[product id=”1794″]

Supercharger Description

Speedwell Supercharger kit for Volkswagen 25/36 HP engines (1949 – 1960). On the outside the Speedwell supercharger looks like the 1950’s supercharger. However, on the inside, it gets better…. The internal parts have been redesigned to outperform the original period supercharger. The shafts are 4140 chrome-molly steel and run all the way through the rotors. The 8620 carburized gears have switched positions with the bearings, so the bearings now carry the moment load ahead of the gears. The gears have more teeth, an improved pressure angle and a pitch diameter that meshes precisely. This results in less gear friction, reduced noise and increased reliability.

The kit includes the supercharger assembly, carburetor mounting flange, induction flange, drive pulley, two V-Belts, air and main carburetor jets, modified throttle and choke linkages, gaskets, a custom 13mm/14mm “S” wrench, all hardware and an installation manual. If your vintage Volkswagen 25/36 HP engine is from 1949-1954, this kit is 100% complete and ready to install today….no modifications are necessary. If your engine is from 1955-1960, then only one tiny modification is required….you may have to trim the generator pulley in order to clear the the supercharger.

The Speedwell supercharger is absolutely period correct! This masterpiece was designed, cast, machined, heat treated, assembled and tested all completely in San Jose, California. You are getting a quality American product that was hand built to perfection.

Installation Instructions

Remove the crankshaft pulley cap screw (30mm).

Clean paint and burrs from surface of hub around bore of pulley.

Install supercharger drive pulley by engaging register of pulley in bore of original pulley making sure spring roll pins are through the pulley slots.

Replace cap screw and tighten securely making sure the pulley register is properly engaged.

Warning: It is absolutely necessary for the pulley to run concentric and without wobble. Check by cranking engine with starter and observing pulley.
Remove air cleaner. Remover fuel line. Disengage throttle and choke linkage from the carburetor.

Remove carburetor nuts & washers from under induction pipe. Remove carburetor and set on a clean workspace.

Remove two carburetor studs from bottom of carburetor flange (under fuel bowl). Use double nuts to facilitate stud removal.

Remove choke locknut.

Installation Instructions cont.

Remove choke arm and set aside loosely with linkage intact.

Remove throttle arm locknut (save) and barrel nut (save). Remove throttle arm. Remove throttle adjustment screw (save).

Install throttle arm adjustment screw on new throttle arm (supplied with kit). Install throttle with arm pointing towards air horn.

Install throttle arm washer and choke linkage. Install choke linkage barrel nut.

Install new supercharger throttle linkage (supplied with kit) and locknut. Ij

Install new adjustable throttle linkage (supplied with kit).

Installation Instructions cont.

Remove four screws and top owl from carburetor. Set bowl aside with linkage attached.

Caution: The housing around the air correction jet can be fragile.

Replace top bowl and install and tighten four screws.

Remove main jet retainer nut.

The OEM main jet is typically a No. 112 or 117. Replace main jet with nNo. 125 hey (suppleidwith kit). Reinstall main jet retainer nut and tighten. Apply threads-locker sealant to the flat head screws (supplied with kit). Install flange to carburetor with gasket and two flat head screws. Tighten flange screws securely so they will not drop into supercharger and damage rotors.

Installation Instructions cont.

Remove hex head plug in side of supercharger. Apply Teflon tape to threads of oil cup and install oil cup on supercharger.

Remove hex head plug. apply Teflon around threads of breather cap (supplied with kit) and install breather cap to top of supercharger. Use 11mm wrench to tighten snug.

Set carburetor/flange assembly to supercharger with gasket (supplied with kit). Install with bowl facing away from pulley.

Use four pan head screws with lock washers to secure carburetor assembly to supercharger. Tighten screws.

Install supercharger induction flange with gasket. Secure with pan head screws & lock washers (supplied with kit).

Remover voltage regulator from generator. Install two small adapter brackets (supplied with kit) between generator and voltage regulator using brackets.

Installation Instructions cont.

Install supercharger loosely on intake manifold flange. Rotate supercharger to install two drive V-belts. Hold assembly firm on flange to determine number of gaskets needed to get proper belt tension. Belts should be snug, but not taut as belts too tight add unnecessary strain on supercharger bearings.

Recommended belt deflection: 1/4 to 1/2”.

Note: On “55” models, it may be necessary to remove approximately 1/8” from flange of generator pulley to keep belts from interfering. Also if severe scuffing of back side of belts is noted by interference on generator pulley capscrew, round corners of hex slightly with a file.

An occasional application of belt dressing will keep belts from slipping and prolong the intervals between adding flange gaskets to tighten belts.

Install slotted brace to crankshaft under head of bolt holding original induction flange brace to supercharger under hex capscrew to left of oil cup.

A slight belt adjustment may be accomplished by springing supercharger and induction piping when bolt in crankcase is tightened.

Install throttle linkage assembly to supercharger. Insert stud into side boss supercharger. Tighten and adjust stud and locknut so that linkage moves freely but not too loose.

Hook up throttle controls. To make spring loaded sleeve slide smoothly it may be necessary to bend steel tube extending through shroud slightly downwards to line up with travel of throttle transfer arm supercharger.

Bend fuel line as required and install from fuel pump carburetor.

Installation Instructions cont.

On models equiped with vacuum advance distributor cut vacuum line and lengthen by use of 1/8” hose.

Fill supercharger with SAE 75W90 Synthetic gear oil through oil cup. Check oil level in cup. Oil level should be maintained about halfway in cup.

Oil should be drained from supercharger and replaced at same intervals engine oil is changed.

Start engine and after warm-up, set idle speed and mixture. A top lube in the fuel is recommended for the first 500 miles to aid in breaking in the supercharger seals.

When the foregoing instructions are followed, the operation and performance should be satisfactory for ordinary highway driving. Under continuous over-speeding, or full throttle operation of the engine, an electric fuel pump is recommended to ensure proper fuel pressure to carburetor. When fuel pressure drops or carburetor leans at high speed, serious damage can result to pistons valves and cylinder heads. For higher performance, it is advisable to use a relieved muffler, use larger venturi with suitable jets and bleeds and remove preheat tubes from intake manifold. An exhaust gas analyser should be used to obtain proper air-fuel ratios. Remember spark plugs are cheaper than pistons.