Tech Articles

Installing the Supercharger Kit


A full set of photos of the supercharger installation will be added soon.

Supercharger Installation Instructions
Partially Updated 5/25/06

Over the past 6 years these instructions have been changed based on the feedback from prior customer installations and this process will continue with your help. A version with photos will soon be available on our website.  If you have a problem during installation or find that these instructions are not clear, please let us know.  There are a number of differences between Volvo models and model years and variations in your car's setup from those that we have so far encountered may require modifications in how some parts are installed. Feel free to call or email me at any time if you have questions.
The supercharger kit is designed to be a weekend installation that requires moderate mechanical skills and readily available tools. However, there is a fair amount of work involved, and it has to be done correctly, so most people may want to spread it out over several days. Fine tuning for maximum performance will take even longer, but that's where a lot of the fun comes in.
Please note that installation on some models in certain states or countries could violate emission control or other regulations. In most states the cars that the supercharger is designed for are old enough to be exempt from these regulations. In those states or countries where there is not a clear exemption the system is sold for off road use only.
Significantly increasing the power of a vintage car should not be done without first evaluating carefully the condition of all of the other systems of the vehicle, especially those related to the  suspension, handling, braking, and safety. This evaluation should be done by a qualified mechanic. All upgrades and/or repairs recommended should be done before the installation of the supercharger system. Although suspension and drive line upgrades are recommended by us for all vintage Volvos, they should be considered mandatory for those using the SC system at high boost / power settings. Vintage Performance Developments offers an extensive line of parts designed to upgrade these component systems. 
Please read all of these instructions before starting, and email or call with any questions that you may have.

Pre-installation Preparation

Oil Change
Some things are recommended in terms of preparation. The oil and filter should be changed and we strongly recommend using synthetic oil such as Mobil One. For hot climates ( Cal, Florida, Texas ) we recommend the 15/50 grade.

Windshield Washer
On models where the windshield washer is located on the firewall behind the intake manifold/carb area, it should be removed and may have to be permanently relocated.

Particularly on the 1800, the battery must be temporarily removed in order to have the access necessary for a proper installation of the supercharger/intercooler/manifold unit. It can be replaced once the supercharger/intercooler/manifold unit and carb are installed. A smaller than stock battery will allow the use of a larger air cleaner which may be better for performance. 

On a 122 the size of the battery is critical to having enough room to install the carb and air cleaner. With large batteries there may not be room for the air cleaner supplied with the kit. As  sufficient air flow is probably not possible with a shorter air cleaner, it is recommended that a smaller battery be installed, or, as an alternative, the battery can be moved to the trunk.
Supercharger Support Bracket
The support bracket for the supercharger goes from the bottom of the supercharger to the engine block. It is designed to attach to the screw hole on the block where the brace for the injected manifold bolts to the block. On some early blocks this tapped hole my not exist. In that case a modified brace will be needed that attaches to the top motor mount bolt. Please check this and let me know so that I can send you the proper brace.  A further modification may have to be made to the brace if you have a generator instead of an alternator. Changing to an alternator is highly  recommended and necessary if a tubular header is to be installed along with the SC.

Fuel Injected Cars
Fuel injected cars have a good deal of additional equipment necessary to operate the FI system that is not necessary for the supercharged engine. This is true whether the supercharger system will be operated with a carb or new FI system. Although the supercharger system can be installed with the injectors and fuel rail in place, unless the plan is to use the superchager with a FI system, it is advised that the injectors and fuel rail be removed so that there is more room for the installation. The injector holes can be plugged with readily available freeze plugs. The sensors and some wiring for the FI system can be removed to make more space for the SC installation. The large sensor on the front of the head must be removed. As this is a water temp sensor the opening in the head must be blocked off with a plate and this should be done before attempting installation of the SC system.  In order to operate the fuel system, you may find it easier to leave the related FI system wiring in place. This includes the ground wires in the ECU wiring harness, the wire to the FI points, and the ECU. With these items left in place the fuel system will operate in a normal manner, with the pump coming on when the key is turned on, and shutting off when there is sufficient pressure or when the engine is not operating.
For a carbed application, in order to provide fuel at the proper pressure the stock fuel "in" and return lines should be plumbed to a fuel pressure regulator with a range that allow adjustments in the 0 - 7 psi range. I suggest that a small fuel pressure gauge be attached to the regulator for ease in adjusting and checking that the pressure stays in the proper range. For the Weber carb supplied this should be between 3 and 5 lbs.

Other "Space" Issues
On many of the models the supercharger system was designed to fit, it is a close fit and any changes in the car from stock may create "space" problems.  As we could not accommodate all possible changes, testing of both installation and operation was done on typical cars assumed to have stock components. In developing the system from prototype to production versions, we made sure that the system would fit these vehicles. Any changes from stock may create problems.   So far we have encountered problems where owners have installed larger than stock batteries, heavy duty engine and/or transmission mounts, or have removed the stock caster adjustment shims between the front cross member and the body (this raises the engine in relation to the body ).  All of these problems can be dealt with as they are encountered.
In the 1800 these "space problems" are perhaps most critical in terms of hood clearance. Although I have installed the system on several 1800s in our shop without problems and even without any modifications, there are customers who have had hood clearance problems. It is tight, but should fit. The most significant problem may be the removal of the factory shims between the cross member and the frame which are used to set caster. This brings the front of the cross member up and raises the front of the engine. A weak rubber trans mount may also allow the rear of the engine to sag and raise the front. Solutions range from replacing the shims between the cross member and the frame which raises the body in relation to the cross member, installing modified steel motor mount brackets with slotted bolt holes, installing thinner rubber ( the stock 544 mount is the shortest ) or poly motor mounts, to installing a modified or shimmed transmission mount. Some customers have chosen to modify the hood with a slight bulge or dimple for clearance, but we do not recommend changing the classic outside appearance of the 1800 if it can be avoided. 

Head Bolts
If the head has not been off the car for some time, or if it was not retorqued warm after the most recent installation, we suggest that the head bolts be retorqued to the factory spec of 65 ft. lbs. using the proper sequence, with the engine warm.  If the head is off the car, we recommend that it be re-installed using head studs such as those sold by ARP. We can provide these or you can obtain them from an ARP dealer or direct. The part number for most heads is AP5.5L, with the nut being APN58, and washer APW1316.

Head Gasket
If the head is off, obviously a new head gasket should be installed. We do not recommend any of the thicker head gaskets as these destroy the "squish" action designed into the head. Ideally the depth of this area ( head gasket compressed thickness + deck height )  should be in the .030 - .040 range. Use a gasket with approx. .030 - .035 compressed thickness if possible.

Intake - Exhaust Gasket
We recommend that this gasket be replaced with a new gasket as part of the installation process.

Ignition Timing
Timing is critical in tuning an engine. To be sure that the timing is close for your first start up of the supercharged engine, I suggest that you check and reset the timing on the engine before you begin the supercharger installation process. A setting of 12 - 14  deg. at 1000 - 1200 RPM, or 10 degrees at idle is a good starting point. Also check the timing at full advance, over 3,000 RPM. Timing at this RPM with full mechanical advance, vacuum advance or retard disconnected, should be no more than 32 deg. If your distributor has vacuum retard, we suggest disconnecting it permanently. Vacuum advance distributors are preferred. If there is detonation, pinging, the timing may have to be retarded.

Installation of the Intercooler Radiator System
Installing the intercooler radiator It is recommended that the components of the intercooler radiator system be installed first. This consists of the intercooler radiator, water pump, hoses and filler tank. For those of you who drive your cars everyday, this part of the installation can be done while keeping the car in driveable condition, although removing the car's radiator may facilitate access. It is important to lay out the location of all components before the actual installation is started. The water hoses are 3/4 inch cooling system hose and can only be bent to a limited degree without restricting flow.
The radiator is installed behind the grill, in front of the car's radiator so the first step is to remove the grill. In most models the best location for the coolant pump is on the passenger side of the grill opening, slightly lower than the intercooler radiator so that coolant can drain from the IC radiator into the pump.  A hose from the bottom of the intercooler radiator goes to the center inlet on the pump. Photos of the installation are, or will soon, be available on our website and should give you a guide as to the layout. Aluminum straps/strips , approx. 1" x 1/8" or 3/4" x 1/8" available at most hardware stores, are used as  mounting brackets for the intercooler radiator. These should be mounted horizontally across the car's radiator opening with sheet metal screws, pop rivets, or small bolts attaching them to the sheet metal on each side of the car's radiator. If the car's radiator is still in place the utmost caution must be taken not to drill into the radiator. It is important to dry fit all components before any drilling or cutting.
First measure the width of the opening and cut the aluminum strips to the correct length. Determine whether sheet metal screws or poprivets will be used to mount the aluminum strips. If using poprivets, we suggest that stainless steel rivets of 3/16 inch diameter be used.  Drill holes in the ends of the AL strips that match areas on each side of the radiator opening where holes can be drilled in order to mount the strips. The strips have to be mounted far enough apart vertically to attach them to the mounting tabs on the intercooler radiator. With the strips in place, mark matching holes in the sheet metal on each side of the radiator. After drilling the holes, temporarily install the mounting strips. With the strips in place locate the intercooler radiator in relation to the strips, and mark the location in the strips where holes need to be drilled to attach the Int. radiator. Remove the strips from the car to drill the mounting holes. Depending on your car model it may be easier to attach the radiator to the strips before installing them in the vehicle. Before doing the final installation, with the intercooler radiator temporarily held in place, lay out the positions of the water pump and hoses to be sure there is sufficient clearance.  The hose needed for the installation is 3/4" coolant hose available at any auto parts store.
Installing the water pump and hoses The water pump is normally installed in front of the left (facing the front of the car ) side of the intercooler radiator with the pump inlet ( center ) facing to the right, the outlet pointed up. On some cars a hole has to be drilled ( with an appropriate size hole saw ) to the left of the radiator in order to rout the water hoses into the engine compartment. This is not necessary on the 1800 E and ES and some 140's as the hoses can be routed through the air intake hole after the air cleaner is removed.  Once the water pump is appropriately located,  mark holes for mounting bolts. Drill the holes.  Once all holes for mounting the radiator and pump are drilled, they can be installed, with the intercooler radiator being installed first.
The black wire from the pump should be grounded to a screw or bolt close to the pump. One of the mounting bolts can be used.  The red wire is the positive lead and should be connected to a source that is on only when the ignition is on. The feed should be fused. We suggest that the line also be switched so that the pump can be turned off if there is a leak or problem with the water system, as running the pump dry can damage it.
Once the wiring is completed the hose can be connected between the bottom intercooler radiator outlet and the lower outlet on the water pump. Slide hose clamps over the hose ends before sliding the hoses onto the outlets. The hose from the top of the pump goes to the bottom of the intercooler. A hose with two right  angles in it is provided to go from the top of the pump through a hole in the sheetmetal on the side of the radiator into the engine compartment. This hose will eventually be attached to the bottom of the intercooler at the front of the engine using a plastic connector  included in the kit with hose barbs on each end and an additional  piece of hose.  This connection must wait until the intercooler is installed.  The hose from the side of the intercooler radiator will eventually be connected to the front of the intercooler filler tank.

The Intercooler filler tank - The intercooler system filler tank should be mounted in the highest possible location, higher than the actual intercooler.  It is designed to be mounted to the passenger side inner fender as far to the rear as possible. On 1800E and ES cars the FI air sensor should be removed to make room for the tank.
A small aluminum mounting plate with two holes is usually included in the kit. (If not included it is made from the same aluminum strips used to mount the intercooler radiator.)  Drill two holes in the inner fender matching the holes in the tank mounting plate.  The tank is held to the plate by one or two large hose clamps that go around the tank and mounting plate. Test fit the tank in place and determine that it clears the hood, etc. before permanently attaching the plate, and determine whether one or two clamps will be used. Put the clamp(s) around the mounting plate before permanently attaching it to the inner fender. 
Once the tank is mounted the 3/4 inch coolant hose can be connected from the front outlet of the tank to the upper outlet on the intercooler radiator. Slide hose clamps over the hose before sliding the hose over the outlets. The hose from the side of the filler tank will be connected to the back of the intercooler after it has been installed.
Preparation for Installation of the Supercharger/Intercooler Unit
The next step in the overall installation process is to remove the car's intake manifold. This will be replaced with the supercharger/manifold/intercooler unit. But before the supercharger/intercooler unit is installed some preparations need to be made.

The Oiling System
The supercharger's gears are lubricated and cooled with engine oil. The source for hooking up an oil line, the blue hose provided, is the passenger side of the engine block where there is an oil outlet for the oil pressure gauge on some of the cars. If your car has a pressure gauge, use the provided brass "T"and nipples  to connect to outlet in the block, allowing an outlet to the pressure gauge and another to the supercharger. If there is no pressure gauge, there is a plug in the block to the right of the oil filter. This plug should be removed and a 1/8th NPT hose barb fitting for the oil line is installed in place of the plug. ( A thread sealer or teflon tape should be used on all threaded connections to assure a good seal.) A right angle fitting will facilitate clearance with the exhaust system and other components.  Use a hose clamp to secure the oil line to the fitting. In most kits a blue high pressure line is provided. This line must me carefully routed to clear the exhaust manifold up to the oil fitting on the top of the supercharger closest to the engine.
Two other oil lines are needed. As these are not high pressure lines, black fuel line can be used instead of the blue high pressure hose.  One is an oil return line from the bottom of the supercharger that returns the oil to engine. On cars with a mechanical fuel pump this is connected to the modified breather supplied that replaces the normal breather on the distributor side of the block. On cars with an electric fuel pump the oil return is usually connected to a fitting in the plate that blocks off mechanical fuel pump mount hole. This oil return line starts under the supercharger, at the lowest outlet (closest to the engine) with a right angle fitting, and is routed across the front of the engine to the lower connection on the breather or either connection on the fuel pump block off plate. A bracket will allow the hose to be held to the front of the head close to where it crosses over the water pump and fan belt pulley. It is important that the hose is routed as horizontally as possible, with a slight down angle from the supercharger outlet, allowing the oil to drain by running downhill. Some customers have found it easier to use hose at each end with a section of 1/4" steel tube ( brake line tube is the easiest to get ) forming the center section in front of the head.   If this routing is not possible, an alternative is to rout the line down under the front of the engine, just below the crank pulley,  around the timing cover, attached to the front cover bolts with brackets. The third oil line is a breather line that is routed from the top of the supercharger, the port farthest from the engine,  to the top fitting on the modified breather or either fitting on the fuel pump block off plate.   
If the oil and oil filter have not been changed, I suggest that they be changed at this time, as it is much more difficult to get to the filter after the supercharger unit is installed.  We strongly suggest that synthetic oil such as Mobil 1 be used.
If the car has an oil pressure gauge, and all should, inspect the flexible line to be sure that it is in good condition. If it is 30 years old it should be replaced.

The Crank Pulley
The engine's standard crank pulley has to be swapped for a pulley provided in the kit. Early kits used a modified pulley originally used on cars with AC. Later kits have a custom made aluminum pulley. To change pulleys loosen the alternator bracket bolt holding the alternator belt in tension so that the alternator/water pump belt can be removed. Remove the belt. Unscrew the crank bolt. If there is a problem unscrewing the crank bolt, have someone sit in the car, with the car in gear,  with their foot on the brake as torque is applied to the bolt.  Remove the pulley.  If you have the typical sheet metal pulley, after removing the pulley you must remove the sleeve that fits over the end of the crank. Do not worry if it is damaged in being removed as it is not needed again. To remove it, you may have to grip it with vice grips and pry outward against the vice grips with large screwdrivers or pry bars. In some cases you may have to remove the front timing cover in order to get sufficient access to the sleeve, but this is normally not necessary. In  any case, the collar should be considered expendable, while the crank snout must remain unaffected and undamaged.
If the crank seal is the old style felt seal, we recommend that the timing cover be replaced with a cover that has been modified to use the later type neoprene seal. We can supply these modified front covers on a core exchange basis. If this has not been done, the felt seal should at least be replaced with a new one before the new crank pulley is installed. If the front cover has been removed be sure to re-center the cover in relation to the crank per factory guidelines. Some oil should be spread on the collar of the new crank pulley where it will contact the seal, before it is installed. Installation is a simple slip on. Before permanently installing the new pulley, check to see that the bolt will engage the crank with sufficient threads. In some cases a longer crank bolt may be needed. ( Cars that originally had a cast pulley normally have the longer crank bolt ). With the aluminum pulley it is extremely important that the slot in the pulley be exactly lined up with the key on the crank. If it is not lined up properly when the bolt is tightened, the aluminum pulley can easily be damaged on installation. Install it slowly and carefully and  tighten the crank bolt  to approx. 65 ft.lbs.
The alternator/water pump belt can now be replaced.  However, I suggest that you wait to re- install the belt, as being able to move the alternator will facilitate access to other components during their installation. A longer than stock belt will allow the alternator to be tilted farther away from the engine and help with clearance issues.

The Supercharger Support Brace
The last preparatory step is to mount the supercharger support brace to the block.  The bottom hole on the brace is attached to the block through the hole on the B20 block provided for the FI intake brace. This should be done with a bolt and lock washer provided. If you have a block that does not have this hole, a different support bracket will have to be provided that attaches to the top bolt of the motor mount.  Use blue Loctite and a lock washer on the bolt, but do not tighten the bolt yet, as some movement is necessary in the installation process. The top of the brace will later be attached to the bottom of the intercooler with bolts provided.

Installation of the Supercharger/Intercooler Unit
The supercharger/intercooler/intake manifold unit is provided assembled into one unit and is not designed to be disassembled by the car owner.  (It is assembled using an anaerobic gasket forming material that would need to be entirely removed and replaced if any sections of the unit are disassembled. If there is a problem requiring disassembly the unit should be returned  to us for repair.) The unit mounts in the same manner as the car's original intake manifold but is much  heavier so extra care must be taken.
Before mounting the supercharger unit, check to be sure that the oil line attached to the block is properly installed with the clamp tight on the hose. We recommend that a thread sealing compound or appropriate tape be used on all threads in the oiling system to prevent leaks.
Prior to installation, you should measure the thickness of the intake manifold flange and the exhaust manifold flange to determine whether offset thickness washers are necessary where one stud serves to clamp down both the intake and exhaust manifolds. (Exhaust manifolds, even stock Volvo, have different thicknesses at the mount flange.)  It is very important that if the thicknesses are different adapter washers be used so that the clamping action will be even on both manifolds and will not bend the studs when torque is applied.
Washers and lock washers should be used for installation in order to prevent loosening under vibration. It is crucial that equal pressure/torque be applied to each of the nuts on the head studs in order to distribute the load of the weight of the supercharger evenly. Failure to do this, and maintain even tightness, may result in a cracked intake manifold and/or intake or exhaust leak. 
If the manifold mounting studs are rusted or the threads otherwise "beat up", we suggest that the studs be replaced or at least cleaned up with an appropriate die. This will make installation much easier in the long run, and allow even torque to be applied to each nut. The studs are normally 5/16 coarse thread.
It is vitally important that the manifold be installed evenly in terms of vertical height on each end.  There is some play and it is possible to install it with one end higher than the other. The top of the head should be used as a reference and both ends of the intake manifold should be even with the top of the head or both should be an equal amount above or below it.  The goal is to have the top of the supercharger parallel to the top of the head. Failure to do this can result in misalignment of the supercharger pulley and problems keeping the drive belt in the proper position on the pulley.
Each stud should have at least one thick washer, a lock washer and nut. (Nylock nuts are usually not affective as the heat will destroy the locking material.) I suggest that two washers be used on those studs where the washers will have to put pressure on both the intake and exhaust manifolds. It is vital that either the flanges of the intake and exhaust manifolds be equal thickness or that special washers be made up that will accommodate any difference in flange thickness. If this is an issue contact me for further information.
It is admittedly difficult to access the two lower center manifold bolts. It can be done, but takes some time. It is a left handed operation that requires both a hand under the manifold and a thin screwdriver or like instrument used through gaps in the intake manifold to assist in getting the washers and nut on the studs. If you have a friend with small hands who is good at manipulating parts in a small space ( a left handed surgeon would be good ),  you might want to ask for his/her help, otherwise, just take your time and put one washer on at a time. Once the nut is started on the stud a ½ inch socket, preferably a swivel socket, on a 3/8 drive extension must be used to tighten the nuts on these lower studs. Tightening should be done evenly, with none of the nuts being fully tightened until all of the other nuts, top and bottom, have at least been snugged up. Before fully tightening the nuts, check again to be sure that the manifold is sitting evenly in relation to the head. Then go over each nut on each stud and make sure that they are equally tight.

The Support Bracket
The next step is attaching the support bracket to the supercharger. Be sure to use a lock washer and Loctite or other thread locking compound on the bolts that go into the supercharger. This is a metric thread, so be sure to use the correct bolts, normally provided. It is vitally important that tightening these bolts not put any downward pressure on the supercharger. If the bolts cannot be snugged up without pulling down on the supercharger,  washers should be used between the brace and the supercharger to assure that tightening the bolts does not apply any downward pressure. Once the top bolts are attached and tightened with the bottom hole of the bracket loosely attached to the bolt on the block, the bolt attaching the support bracket to the block should be tightened. Again, be sure that tightening this bolt does not put any pressure on the brace. If the bottom of the brace sits out from the block, remove the bolt and place one or more washers behind it so that when the bolt is tightened it will not put any pressure on the brace tending to bend it or pull down on the supercharger/intercooler unit. These bolts should be checked periodically to be sure they have not loosened. 

Oil fittings
Next, install the oil fittings in the supercharger. There are three right angle fittings that are installed into the threaded holes at the front of the supercharger - two on the top and one on the bottom. Two, or in some cases, three of these fittings are externally identical, but one of them has a restrictive orifice screwed into it. This fitting is the "oil in" fitting, and is installed in the top of the supercharger, in the port closest to the engine. It is critical that this fitting with the restricted oriface be attached to the oil delivery hose from the block. Another fitting, either angled or straight, is the "oil out" fitting and goes in the bottom of the supercharger in the outlet closest to the engine. The third angled fitting is the breather and is installed into the threaded hole in the top of the supercharger farthest from the engine. For 1800s and other models where hood clearance is a problem this is a smaller fitting than the other two, and has been custom made to provide as much clearance in relation to the hood as possible. Each of these fittings should have a washer with an "O" ring attached between the fitting and the supercharger. The fourth port in the supercharger should be filled by a threaded plug which should also be backed by an "O" ringed washer. Do not make substitutes for any of these fittings as the threads in the compressor are not the common NPT thread, but are British Pipe Thread.

Oil Lines
The next step is to attach the oil lines to the fittings in the supercharger. The oil "in" line from the block goes to the top fitting closest to the block.  A hose from the top of the breather ( or fuel pump block off plate ) goes to the other top fitting. In some cases this hose is a smaller diameter than the other hoses. The hose from the side of the engine breather on the distributor side ( or fuel pump block off plate ) goes to the outlet on the bottom of the supercharger. (Make sure that this line is solidly located so that it clears and will not rub the fan belt pulley.)  Tighten the hose clamps on each oil line. Once the engine is started these oil hose fittings should be regularly checked to be sure there are no leaks.

Intercooler Coolant Hoses
The coolant hoses from the filler tank and the coolant pump should now be connected to the intercooler. A straight, metallic fitting is provided for the bottom-front of the intercooler. An angled fitting, usually plastic, is provided for the rear of the intercooler. Thread sealer or teflon tape should be used on both of these fittings. The  hose from the back of the intercooler goes to the connector on the side of the filler tank. The hose from the top of the coolant pump goes to the bottom of the intercooler. Check that the coolant flow path is from the top of the coolant pump, to the bottom of the intercooler, from the back of the intercooler to the filler tank, from the filler tank to the side of the radiator, and from the bottom of the radiator back to the center port on the coolant pump.  Fill the intercooler radiator system with water, mixed antifreeze. Even in climates where freezing weather may not be encountered the antifreeze provides corrosion protection. Loosen the vent on the top of the intercooler and keep it open until a steady stream of fluid exits from intercooler as you are filling the system.  After the tank appears to be full, start the water pump and allow it to run with the filler tank cap off to vent air. Noise from the pump usually indicates that there is still air trapped in the system.  Over a short period of time the air should vent and the system may need additional fluid.

Gauges and Vacuum/pressure lines
All gauges, especially the boost gauge, can now be attached.  1/8 NPT holes are provided on the intake manifold for lines to the boost gauge and for a feed to the ignition controller and/or vacuum advance distributor if they are being used. Use 1/8 flexible copper tube, not the plastic tube commonly supplied with the gauges. The plastic tube can melt and create a vacuum leak. A thread sealing compound should be used whenever fittings are screwed into the intake manifold to prevent vacuum leaks.

The Supercharger Pulley and Drive Extension
The large screw on the side of the SC drive extension tensions an internal spring that applies pressure to the shaft to counteract the pressure of the drive belt. If the supercharger was delivered with a pulley installed, this screw is pre-torqued to 20NM ( approx. 13 foot lbs.) and a sealer has been applied to the threads. If the pulley is not installed as delivered, or if there is an oil leak, or other reason to remove this screw it is important that it be re-torqued to 20 NM with an appropriate non-hardening thread sealer on the threads, with a SC pulley bolted in place and properly torqued to 60 NM. This should be done before the SC drive belt is installed. At 20 NM the screw will bottom out  on a shoulder in the extension so tighten it slowly to be sure not to damage the threads. Failure to do this will result in the eventual failure of the supercharger drive extension and damage to the supercharger unit.  If the SC pulley needs to be removed or installed a special tool will need to be used ( which you can make ), to hold the pulley from turning while the bolt is tightened or loosened. Please contact me for further information if this is an issue.
The supercharger is normally shipped with a 57 mm pulley, other diameters are usually stocked. Crank pulleys are normally either   120 mm or 127 mm. You can compute the drive ratio by dividing the crank pulley diameter by the supercharger pulley diameter. 120/57 =s 2.10 ratio.  127/57 =s 2.22 ratio. Multiplying this ratio by the engine rpm gives you the supercharger rpm at any engine speed. Higher ratios will normally produce higher boost pressures at any particular engine rpm.  

Installation of the Belt Tensioner and SC Drive Belt.
There have been several changes to the belt tensioner system. The current version consists of two pulleys mounted on a plate, backed by spacer blocks, mounted to the front of the intercooler. The position of each pulley is adjustable with the pulley closest to the supercharger being spring loaded to apply constant pressure to the belt.  Although the SC may be delivered with the tensioner pulleys and their mounting plate installed, adjusting the position of these pulleys is part of the process of installing and tightening the SC drive belt. Different positions of the tensioning pulleys, as well as different length drive belts may be necessary depending on the size of the SC drive pulley that is being used. For newly rebuilt engines, we recommend running a drive pulley that will result in no more than 8 lbs. of boost during the initial break in period - approx. 500 miles.
It is also possible, due to casting variations in the head, block and intake manifold, that some adjustments must be made to align the crank pulley with the SC pulley.  This adjustment may require using different thicknesses of spacers behind the SC pulley on its shaft ( the SC is supplied with a standard spacer ) , washers under the tensioner pulley mount plate to shim it out, or a thinner spacer block behind the pulley mount plate to move it back towards the engine. We can provide a thinner tensioner spacer block if needed, or the one provided can be milled by any machine shop if the tensioner pulley needs to be moved towards the rear.  Different widths of drive belt can also be used to help with some alignment problems, but we strongly recommend the use of a 6 rib belt.
The aluminum crank pulley provided normally has 7 grooves, allowing a 6 rib belt to be mounted in two different positions. The extra groove is provided to accommodate differences in alignment. Normally a 6 rib belt is mounted on the outer 6 grooves leaving the groove closest to the engine empty. Most applications will use either a 50.5 inch, usually designated 505K6, or  51 inch           ( 510K6 ) 6 rib belt. A smaller belt may be necessary if a smaller supercharger pulley is installed to increase boost.  
A straight edge such as a good quality yardstick can be used to judge whether the pulleys line up with each other and the tensioner pulleys.  If you believe that you have a problem with pulley alignment, let me know.  Installations to date have shown that there are variations in the dimensions of the stock Volvo castings that can make adjustments necessary. The supercharger - intercooler components are all CNC milled and drilled and thus do not have similar dimensional variations but are mounted on stock castings which do vary considerably.  
Three allen head screws provided mount the tensioner pulley system to the front of the intercooler. A spacer block goes between the tensioner system and the front of the intercooler. As with all screws/bolts used in the system they should be loctited, normally using loctite blue. The bolts holding the tensioner pulleys to the mount plate and swivel arm are located behind the pulley covers. The covers must be removed to facilitate belt installation and to allow you to loctite and tighten the pulley mount bolts. This is also necessary to allow the pulley closest to the engine to be adjusted up or down to properly tension the belt.  The bolt holding the lower pulley should be removed, loctited, and reinstalled loose enough that it can be moved up and down in its slot.
The drive belt should now be placed over the crank pulley and then over the SC drive pulley. You should use the smallest belt possible as larger belts may not allow sufficient tension to be put on the belt.   Belts narrower than 6 rib may be easier to install but will transmit less torque and thus are more likely to slip.   It will be easier to install the belt if  the front pulley covers are off the tensioner pulleys. To install the belt, first install it on the crank pulley and then the  supercharger pulley, by passing the tensioner pulleys. You may need to roll the car forward or backwards, in 4th gear, or use a wrench on the crank bolt,  in order to turn over the engine and inch it onto the SC pulley after placing it around the crank pulley.  Start it on one part of the SC pulley,  and then roll the car to turn the belt and the pulley to roll it on the rest of the way on. Be careful that your fingers do not get pinched between belt and the pulley. closest to the engine, with this pulley in its top position, and slide the bottom part of the belt, as it comes off the SC pulley, over the pulley closest to the supercharger.
The lower ( closer to the engine ) tensioner pulley should be positioned on top of the drive belt. With the cap off the pulley, the bolt that holds the pulley to the block is exposed. Loosening this bolt will allow the pulley to be moved up and down in its slot. Move it all the way up to install the belt. By twisting the belt, you can slide the top part of the belt under the pulley.
The top tensioner pulley ( farther from the engine )  should be positioned so that it provides pressure on the underside of  the drive belt where it comes off the underside of the SC pulley. It is spring loaded and will apply constant pressure to the belt. A 1/4" bolt with lock nut should be installed in the bottom of the pulley mount plate to adjust tension on the tensioner spring. This screw should be backed off to install the belt on the tensioner pulley. Again, by twisting the belt, you can slide the top part of the belt over the pulley.  Once the belt is on all pulleys and properly aligned, it is time to tension the belt.
First go back to the pulley closest to the engine. You will be pushing down on this pulley to at least put enough pressure on the top of the belt so that the belt clears the fan belt pulley. Basically, with the belt in place, push down on the pulley as far as it will go and tighten the bolt holding it in place. Loctite should have been placed on the bolt at the beginning of the operation. 
Next, address the tensioner pulley closest to the supercharger. There is a tensioning bolt at the bottom of the mount plate. Tightened this bolt to apply pressure to the belt. Do not tighten it to the point that the spring is in coil bind. If this bolt is not tight enough, the pulley and swing arm may "chatter" at certain rpms. The belt should now be tight enough that it is difficult to twist it more than a half turn by hand.
Now reinstall the pulley covers, with Loctite on each screw.
The engine can now be turned over with the starter motor to see if the belt tracks properly on the pulleys.  The belt will sometimes move until it settles down into the grooves and there may be some additional movement once the engine is started and run at speed. Once the engine has been turned over, check to be sure that the belt is still in the same grooves it started in. The belt should not hang off the end of either the SC or crank pulley. Adjustments are sometimes necessary and both the tensioner pulleys and the supercharger pulley can be shimmed to change their fore and aft location. Belts normally stretch when first run, and may have to be re-adjusted. A belt that seemed tight on the crank and SC pulleys may be loose after the car is run for as short a time as a few minutes. In most cases the belt will stretch to its maximum length within 20 - 30 minutes of running. Adjusting the tension is usually a simple process with the new tensioner system where this is done by the turn of the adjusting screw on the bottom of the tensioner pulley mount plate. Additional pressure can sometimes be applied by repositioning the guide pulley - the pulley closest to the engine.  If there is a problem with belt tracking after running - stretching of the belt beyond the capacity of the system to adjust is a likely cause. This may require going to the next smaller size belt.
A belt that is not tight enough may slip on the pulleys under load. It will often work at low boost and then slip at higher boosts when more power is needed to turn the SC. For example, it is possible that the belt will work fine at up to 6 lbs. boost but will start to slip as the engine RPM and the power needed to turn the SC increases, thus preventing the boost from going higher than 6 lbs.  In this case the boost is being limited to the point at which the power needed to turn the SC at higher RPM equals the power that can be transmitted by a belt that is not as tight as it should be. The only indications of this condition may be boost levels below expectations, boost that does not continue to rise as expected with increased RPM, and the presence of a fine black powder in the engine compartment near the belt.  
Contact me at any time if there are any questions or problems with the belt system.

Carburetor Installation
Most units will be delivered with the carburetor adaptor and mounting plates attached to the compressor.  (If the carb adapter plates are not attached to the SC, or have to be removed for some reason, contact me for additional instructions.) The carburetor is packaged separately from the SC/intercooler unit and must be installed by the customer. The carb now used is a Mikuni HSR 45 specifically modified for this purpose. Do not attempt to use an unmodified carb as it will not work, will cause a lean condition, and could damage the system. Most modifications involve the pump jet circuit. It is expected that some post installation tuning may be required since almost every engine application will be different in some respect.  Exhaust configurations that typically differ from car to car have proved to be crucial both to performance levels and the necessity of additional carb tuning.
The carb installation section is currently being rewritten to include instructions for the Mikuni carb and Fuel Injection throttle bodies. Below is the old section on the Weber 45 DCOE. Some of the information, such as on  throttle cables will remain basically unchanged.

Throttle Cable Installation
All installations are now designed to be used with throttle cables. On cars originally equipped with throttle cables, the cable provided in the kit is designed to be attached to the stock attachment point on the throttle pedal rod on the passenger side of the firewall. For models that came with rod-type linkage, we have worked out an attachment for the throttle cable to the rod linkage on the engine side of the firewall. This requires that a small bracket be installed on the firewall, below the firewall opening where the throttle rod comes through the firewall. The cable sheath is attached to this bracket and the cable to the rod, close to where it comes through the firewall.
The carb is set up ready to attach the cable. The cable system consists of:
1)  a stainless steel braided cable sheath with two threaded end pieces
2) the actual cable
3) a short cable end adapter and a longer adapter ( both usually blue aluminum ) with the longer adapter serving as a length adjuster. Both screw into the ends of the cable sheath end pieces.
4) end fittings for each end of the internal cable - a barrel shaped fitting for the carb end and either a threaded adapter or a crimp-on fitting for the firewall end. 
On most models the adjuster should be installed on top of the carb mounting plate. On the 1800, with limited vertical clearance, it is usually better to fit the adjuster to the firewall and fit the shorter cable end adapter at the carb mounting plate. 
Adapting the SC Throttle Cable to Rod Type Throttle Linkage Cars
On cars with rod type throttle linkages the cable comes with a threaded adapter attached. This screws into one of the rod ends from the rod type linkage where it comes through the firewall. An angle bracket is included that should be pop riveted or screwed to the firewall several inches below the hole that the throttle rod comes out of. Make sure that it is lined up so that the cable will pull straight through the bracket, not at an angle. One of the blue adapters goes through the hole in the bracket and is secured with a nut. The cable sheath is then screwed to the adapter. The longer (blue ) adjuster should be screwed to the other end of the cable sheath. The actual cable should then be inserted through the bracket on the firewall into the cable sheath, and out through the adjuster on the other end. It is now ready to attach the carb.

Adapting the SC Throttle Cable to Cable Type Throttle Linkage Cars
Installation in a car that originally had a cable type throttle is similar. On these cars the original throttle cable was attached to a rod attached to the throttle pedal on the passenger side of the firewall. The stock attachment bracket to this rod is retained and will be used with the cable supplied with the SC kit. Pay particular attention to the way the stock cable attaches to the throttle pedal rod as the SC cable will be attached in the same way.  One of the blue cable adapter ends ( the longer adjuster in the 1800 ), is attached to the firewall where the stock cable comes through it. The other blue cable end adapter is attached to the bracket on top of the carb mount plate.  Screw the cable sheath to each of these ends.  After measuring the approximate length of inner cable needed, crimp a stop on one end of the cable. A good blow with a hammer against a solid backstop will do. The cable should then be threaded through the bracket attached to the throttle rod, and into the cable adapter screwed into the firewall, and through the cable sheath.     

Depending on your car model the exact sequence of steps in attaching the cable to the carb may differ.  It may or may not be easier to attach the cable adjuster to the bracket on the carb mount plate before attaching the cable to the carb. In any case, the small, brass, barrel shaped fitting goes on the end of the cable and then into the round opening in the cable attachment arm on the side of the carb. With the set screw backed out the cable can slide through the fitting to adjust for approx. length. ( If you loose the set screw, do not panic, they are available at most hardware stores. If you loose the brass fitting, it can be replaced with a cable end fitting used for lawnmower throttle cables that are also available at most hardware stores.)  Additional slack in the cable can be taken up by extending the adjuster.
If yours is a model that we have not yet done an installation on, the cable provided may have to be assembled and cut to length, as will the sheath. End fittings will be provided for the sheath that will have to be installed on the sheath once it is cut to length. Dry fit all parts first to determine the lengths necessary.  Provided is a cable stop or a threaded end that is crimped onto the cable and serves to prevent it from pulling out of the stock throttle linkage.  Once the correct length has been determined and the "stop" attached to the cable, the cable is attached in the same manner as the stock throttle cable.  "Slack" or "play" should be adjusted out using the cable adjuster mounted on the carb mounting plate.
Make sure that the throttle plate ( the carb butterfly ) closes all the way with the idle speed adjustment screw backed all of the way out. You want to be able to adjust the idle speed with the adjustment screw, not with the cable slack adjuster. Also make sure that the plate opens all the way when the throttle pedal is depressed to its limit.

Throttle Return Spring
It is important that an external throttle return spring be installed on this type of carb. One is provided along with an extension rod. The extension rod attaches directly to the engine side arm on the throttle shaft. It is attached to the return spring, which is attached to the fitting that provides oil to the supercharger. Make sure that it works freely without hanging up. The extension rod may be bent, or otherwise modified to assure smooth operation. Different lengths of extension rod, and/or spring can be substituted to achieve the desired return spring tension. Without sufficient tension on this spring the throttle shaft may not return all the way to the idle position due to the stiffer pump jet spring installed in the carb.

Choke Cable
The 45 DCOE comes with a manual choke. For Volvo models that came with a manual choke you will already have a choke cable, that may or not be of sufficient length to operate the weber choke. Thus, a cable is not provided in the kit. The choke lever, or more properly, the cold start fuel enrichment valve, is located at the back top of the carb, between the float bowl and the mount plate. When installing the "choke" cable, be sure that the "choke" arm has full travel.

Air Cleaner
It is crucial that the system not be run without an air cleaner. The rotors in the supercharger operate with very small clearances and any dirt or other foreign particles can damage the rotors. An air cleaner is normally provided as part of the kit.
Fuel line Installation
For cars that were originally carbed, the installation of the fuel line is the same as for the original carbs, although a longer length of fuel line may be needed to reach the new carb location. As originally provided, there should be a filter in the fuel line.  If it has not been changed recently, do it now. Be especially careful with all fuel line connections. Be sure that all hose clamps are tight, and check for leaks on initial startup and frequently thereafter.
For cars that originally had FI, the installation is more complicated. For a carbed SC application, in order to provide fuel at the proper pressure the stock fuel in and return lines should be plumbed to a fuel pressure regulator with a range that allow adjustments in the 0 - 7 psi range. The left hand ( distributor side ) inner fender is usually the best place to mount this as the stock lines will reach it. I suggest that a small fuel pressure gauge be attached to the regulator for ease in adjusting and checking that the pressure stays in the proper range. For the Weber carb this should be between 3 and 5 lbs. As with all other fittings we recommend that a thread sealer be used on all fittings and that they are checked on initial pressurizing of the fuel system and frequently thereafter to guard against fuel leaks.

Final Checks, Start UP, and Tuning
Now is the time to go over everything and make sure that all bolts and hose clamps are tight. Check the routing of all of the lines to make sure they clear the header and all moving parts. Check the oil level. Check the coolant level in both the car's radiator and the intercooler system.
Run the intercooler pump with the filler tank cap off to release any air trapped in the system and fill with more coolant as necessary.  Open the vent on the front end of the intercooler. If the air has been vented from the system coolant should come out of the vent without bubbles. If the coolant pump is making more noise than a smooth hum it is probably cavitating on trapped air and further venting will be necessary.
When everything checks out OK, start the engine briefly and check further for any leaks once the oil system is up to pressure. Be sure to check carefully for oil leaks before driving the car. You should also check to be sure that the supercharger is getting oil. There is a restricting orifice in the oil line to the supercharger. This can be plugged by small particles in the oil so it is wise to pull off the oil return line and verify that oil is running through the system once the oil pressure is up. This should be checked again if any unusual noises start coming from the front end of the supercharger.
Check the carb and fuel line connections for any fuel leaks.
Blip the throttle while watching the SC drive belt to be sure that it has not jumped grooves on the pulleys.  This would be an indication that more tension, a shorter belt, or additional alignment work is necessary.
If you have not checked the ignition timing do so now.  The car will run more efficiently if the timing is set at slightly more advance than the factory setting, with 12 to 15 deg. advance at 800 - 1000 RPM being normal.  After checking the timing at idle, rev the engine to 3500 RPM and check the advance at that engine speed. It should not be more than 35 deg.. The total amount of advance depends on what type of distributor you are using and its condition. Record the results for future reference. If you are using a standard centrifugal advance distributor without any provision for ignition retard under boost the total timing should be limited to no more than 32 degrees and may even have to be adjusted to 30 deg. or less to prevent detonation under boost. For systems without an auxiliary ignition system that retards the ignition timing based on either boost level or knock sensing, a vacuum advance distributor is recommended.  With either the knock sensing ignition system or a vacuum advance distributor a greater amount of ignition advance at idle can be used. This usually provides better off idle throttle response.
With the engine having run for a few minutes, enough to be warm, you are ready to adjust the idle jet screws and idle stop screws. This may take several attempts, as changes in the idle mixture screws will change the idle speed. First adjust the idle speed screw that is on the engine side of the carb and contacts the arm attached to the throttle shaft so that the engine is in the 800 - 1000 RPM range. Then turn one of the idle mixture screws at a time out to find the point at which the idle speed is at its highest and then in to find the point at which the speed drops. It should be set approx. ½ turn out from the point at which the speed drops.  Since booth barrels of the carb feed the whole engine, there should be no reason that the adjustment will be much different from barrel to barrel.  This means that you will have to go back and forth between the screws in order to find points where the screws are turned approx. the same amount out, and both are near the point where they affect the idle speed.  If the screws have to be turned more than 3 turns out it is likely that you need to go to a richer idle jet than that provided. The idle jets control essentially all carb tuning up to about 3000 RPM and in part throttle operation, so if the idle circuit is adjusted properly the engine should accelerate cleanly when the throttle is blipped. It is possible to adjust the idle adjustment screws so that the mixture is right at 500 to 1500 rpm, while it is still too lean in the 1500 - 2500 rpm range. If this is the case you need to go to a richer idle jet as the adjustment screws have little affect over 1500 rpm.  If you have a problem, let me know.  
Assuming you have not detected any problems in the above checks, you are now ready to drive the car. Take it easy at first, and just try to determine if everything is running smoothly without the need for major changes in carb tuning. Hesitation, rough running, popping in the exhaust are all indications that the engine is running either lean or rich and needs tunning. Use of the recommended air/fuel ratio meter should give you a good idea which it is. Without the meter, you can have a friend take a look at the exhaust, and/or check the plug color to get an idea if you do not have a meter installed. 
Do not continue to drive the car at speeds where it is running rough, as lean conditions, especially, can cause engine damage fairly quickly. Popping back, or lean backfires, can easily damage seals in the system and cause vacuum leaks. In most instances, if the hesitation is under acceleration at speed under boost conditions the engine will be running lean, especially if gradual applications of throttle produce smooth acceleration while more sudden throttle openings cause the power to go flat.  Going to larger main jets or larger pump jets should cure this. A stiffer pump jet spring will also help. If the hesitation is at low speed it is probably related to the idle circuit and you may have to go back and re-adjust the idle screws. Main jets have essentially no affect on operation under 3,000 RPM
Take it easy during the tuning process, as it is easy to go in the wrong direction.  The carbs should be fairly close as delivered, so small changes should be sufficient. We have a good supply of the various jets and can usually send you jets and other parts necessary for tuning changes.
Changes in the SC to engine drive ratio, made by changing the size of the SC pulley, will change the boost level and may require changes in jetting. I highly recommend installing an air/fuel ratio meter and oxygen sensor as this makes the tuning process much easier and serves to warn of an incorrect mixture before engine damage can occur.

Trouble Shooting


Problem - The car will not start. It has spark and is getting fuel.
Assuming that the ignition timing is correct, the first thing to check is  that the throttle is adjusted so that the carb butterfly will close all the way. If either the adjustment is off or there is a bind in the cable, the butterfly may be hanging up open. This will make it difficult for enough vacuum to be generated to draw sufficient fuel through the carb at cranking speed. With the carb modified with a stronger than stock pump rod spring, an external throttle return spring is usually necessary to ensure that the throttle will close all of the way.

Problem - The car will not start when the weather is cold.
Unfortunately starting in cold weather is a problem we have had with the carbed SC System. With temps near freezing it is hard to start and when started runs rough until it starts to warm up. Part of this is due to a carb design where cold start fuel enrichment is provided rather than a butterfly that limits air flow.
Starting the engine when cold will normally require that the choke be on, and that the throttle pedal be pumped several times to add additional fuel. Pumping the throttle activates the accelerator pump and shoots a stream of fuel into the carb each time it is pumped. There is sometimes a fine line between not enough fuel and too much. After some practice, you will quickly learn the number of pumps that works best in your application.  With engine cold, at temps in the 30 - 40 deg. range or lower, I have found that 4 - 6 pumps will usually get it started, but it may die in 5 - 10 seconds. Four more pumps and it will start again. In really cold weather it may take 3 or 4 cycles of this before it will continue to run cleanly.
In temps well below freezing, the car will usually not start. This is probably due to the necessity of the fuel air mixture having to travel through the intercooler where the fuel may drop out of suspension on contact with the cold intercooler fins. The problem is simply that a design that facilitates operation in warm weather makes cold weather operation difficult. Given the options of good performance in temperatures significantly above freezing, or easy starting in cold weather,  the design choice was fairly easy. A few suggestions for those of you who intend to drive in cold weather are as follows:  The first is to keep the car warm in a garage. The next is to install a heater in the intercooler filler tank so that the intercooler fluid will be warm not cold.  Turn on the intercooler pump to circulate the warmed fluid for 30 seconds or so before starting. The third, and recommended method for cars that will see regular use in temperatures below freezing, is to use the injected version of the system where fuel is injected after the intercooler.

Problem - The car will start and run, but the idle speed varies and the engine speed will not immediately drop down to idle when the throttle is closed.
This is most likely caused by  a vacuum leak. Some of the type 152 weber 45 DCOE carbs have defective