Maintenance

VS57 Supercharger Maintenance

Maintain the oil level in the supercharger sump as indicated by the upper mark on the oil level dipstick. Use only Mobiloil ATF 200, or equivalent  Type A (AQ-ATF quality) automatic transmission fluid. Under no circumstances should any other type of lubricant be used  or added to the oil sump. This includes the use of friction reducing compounds or fluids, or stop leak type products. Total fluid capacity is 8 ounces and this should be checked every 2000 miles or less. Under normal operation it should not be necessary to add lubricant to the sump between intervals of 1500 to 200 miles of operation. Should excessive lubricant consumption occur then the supercharger will require rebuilding.

Under normal operation, the lubricant within the supercharger should retain its original color without darkening or formation of sludge. Therefore, when checking the lubricant level, wipe the dipstick with either a clean cloth or paper and check the condition of the lubricant. Extreme darkening or the presence of foreign matter in the lubricant is sufficient reason to drain and thoroughly flush the lubricant sump. After flushing fill the sump with 8 ounces of Type A automatic transmission fluid.

Drain and flush out the automatic transmission fluid every 3,000 miles, by removing the supercharger from its mounting bracket and draining through the dipstick opening. Refill the sump with 8 ounces of Type A automatic transmission fluid.

Oil the bushing of the idler arm assembly every 2000 miles. Check the oil hole and remove dirt accumulation prior to oiling and, if available, use a pressure type oiler to thoroughly saturate the felt wick.

During zero or freezing weather, should engine operation indicate a rich fuel mixture, check the air cleaner intake for ice formation. In such event, thaw out the ice formation.

UNDER NO CIRCUMSTANCES should any other type of lubricant other than of Type A automatic transmission fluid be used or added to the oil sump. This includes the use of friction reducing compounds or fluids, or stop leak type products.

DO NOT race the engine (and drive the supercharger) without the discharge duct fitted between the supercharger and carburetor bonnet being in place. To do so can result in failure of the supercharger.

NEVER drive the supercharger with the dipstick removed from its housing. This would result in lubricant loss and possible damage to the supercharger.

Direct Oil (VR and DO-VS) Supercharger Maintenance

Change engine oil and filter every 3000 miles. DO NOT use synthetic/semi-synthetic oils, oils containing detergents, or friction reducing compounds/fluids, or stop leak type products. STP (Supercharger Termination Probable) is particularly good at destroying superchargers.

Oil the bushing of the idler arm assembly every 2000 miles. Check the oil hole and remove dirt accumulation prior to oiling and, if available, use a pressure type oiler to thoroughly saturate the felt wick.

During zero or freezing weather, should engine operation indicate a rich fuel mixture, check the air cleaner intake for ice formation. In such event, thaw out the ice formation.

The minimum oil pressure required for the direct oil superchargers is 20 psi at idle and 40 psi under load. If necessary the oil pressure in the engine can be boosted by installing a 5/16 spacer under the oil pump relief valve spring. A low oil pressure is generally indicative of a worn engine, or of problems with the oil system, which should be rectified before using the supercharger. Usage of the supercharger with oil pressures below these minimums will result in failure of the supercharger.

DO NOT drive the supercharger without the discharge duct (connection between the supercharger and carburetor bonnet) being in place, for more than one minute, and never above idle speed. To do so can result in failure of the supercharger.

DO NOT Run the engine for more than a few minutes without the supercharger drive belt being place, without plugging the oil pressure feed to the supercharger, otherwise the supercharger will fill up with oil which will eventually be sucked into the carburetor.

General Comments

It is believed that the reason why a large number of the McCulloch superchargers failed or had to be rebuilt during the late fifties was that the bearings ran dry due to infrequent and/or seasonal usage. To prevent this it is suggested that you should spin the engine without spark or gas for about 30 seconds after a month or so downtime so that oil pressure builds up and the bearings are primed.

Another precautionary measure that is recommended, is that you make sure on each startup before blower use, or shutdown after blower use, that there be a reasonable period of low engine speed so that the oil can get warm and flowing well before/after using the blower. Two minutes up, one minute down would be sufficient to fulfill this.  With that sort of precaution, I believe it was said that the McCullough would last years and years without repairs.

In the case of the direct oil superchargers, the life of the supercharger is heavily dependent upon the quality of the engine oil being fed to the supercharger. Any contaminants or particulates can  score the bearings and races, and eventually destroy them, so apart from the regular engine oil and filter change it is recommended that additional filtration (i.e. OBERG inline filter or similar) is added to the oil supply fed to the supercharger. An inline oil cooler, either for the engine in general, or specifically for the supercharger oil supply, would also be beneficial as it would allow the supercharger to run cooler.

The oil drain from the supercharger is also an area that could be improved upon to prevent potential problems with the supercharger. To prevent blowback from the sump (due to crankcase pressure) an extra large return line, ideally with some sort of baffle system, should be used to connect the supercharger to the sump. Any build up of oil pressure within the supercharger can cause seal damage or failure, and result in oil being forced into the air being blown into the carburetor.

Indeed, the Ford VR57 Phase I, and some early Phase II, installations used a small diameter oil return line which caused problems with more oil getting into the supercharger than was getting out. This was resolved in later Phase II installations via the use of a larger diameter oil return pipe. Also in some Thunderbird installations a restrictor was added to the oil feed to the supercharger to reduce the input pressure, which could be a bit over enthusiastic.

The oil return line from the supercharger to the engine sump should always maintain a continuous downward flow, with no part of the drain hose being below the elbow connecting it to the hose pan. Failure to observe this will result in oil build up in the supercharger and ultimately will lead to oil being blown into the carburetor and potential seal damage in the supercharger.