So you want to supercharge your engine?!?! Here are some valuable tips to making sure your engine (and supercharger) are properly maintained.
Written by James Bertok – Guest Tech Guru
How Will Engine Maintenance Change With a Supercharger?
Supercharging your vehicle is an investment in its capability. Once installed, your vehicle will offer levels of performance you may not have previously thought possible from a vehicle so large and heavy. In return for this newfound power, your car or truck deserves some extra attention in routine and preventative maintenance. As with any routine maintenance, developing problems can be spotted and resolved before they cause damage and become expensive repairs. A little extra periodic care is the best way to protect your investment now and into the future.
Most supercharger kits provide an increase in horsepower of 40% or more. With that increase it’s also fair to say that your motor is working 40% harder and it’s parts need the same amount of additional protection. For this reason the use of exclusively synthetic engine oil is recommended. Some synthetics offer an extended change interval. Changing the crankcase oil at the regular 3000-mile intervals has proven to be the best practice for supercharged engines. Use a proven, good quality filter and synthetic oil such as Mobil 1(for both). The supercharger does not have an affect on the grade of oil required for your vehicle.
Some kits require the installation of a lower-temperature coolant thermostat. The lower coolant temperature provides some necessary help in preventing detonation by decreasing combustion chamber temperatures slightly. A side effect of the lower temperature is that the cooling system will not reach operating pressures as high as it was designed for. Due to the lower pressure, coolant leaks will generally not make themselves as visibly apparent as they would be with a system running at full temperature.
Periodically check the coolant levels with the engine completely cold to make sure coolant is not being lost to a slow unseen weep. If you find that your engine is experiencing a gradual coolant loss from an undetected location, it may be necessary to reinstall the stock 195-degree thermostat temporarily so that the engine can be brought up to full pressure and temperatures. The leak will generally present itself in the form of visible or audible steam. (Escaping steam is dangerous and caution should be used when working with a cooling system under pressure.) Internal coolant leaks from the intake gaskets will result in engine oil contamination visible as a murky appearance and an odor of coolant in the oil. Keeping tabs on your coolant level will help you catch a problem before it can do serious damage to your engine.
An often overlooked component of the fuel system is the fuel filter. The entire fuel system of a supercharged engine will experience flow rates greater than it ever would have before the supercharger installation. A healthy fuel supply is required to keep the engine from experiencing lean conditions in the high rpm ranges where fuel flow is at its greatest. Factory change intervals for the fuel filter are conservative and are usually sufficient. These intervals vary from one manufacturer and type of vehicle to the next but should be followed as punctually as possible.
Carbon build-up in the combustion chamber, with certain combinations of supercharger kits and engine setups, is sometimes more rapid than normal. A number of factors can contribute to carbon build-up such as the lower coolant temperatures and full-throttle fuel enrichment. Carbon build-up will gradually increase the engine’s effective compression ratio and cause hot spots to be present on the top of the piston during the compression stroke – both conditions which will lead to detonation under boost. Carbon is fairly easy to clean out of the engine with any several different, readily available products. GM, for example, makes a product for this use called “Top Engine Cleaner” that is essentially slowly poured into the intake of an idling engine. When the product is gone, the engine is shut off and allowed to sit for 15 minutes after which time it’s restarted and revved up until all the deposits are blown out. It’s very effective and works with all internal combustion engines – supercharged or not. An oil change is recommended after use of such products since they are solvents.
Identify the belt system that drives your supercharger. Some systems replace the stock belt (used to drive the other accessories) with one longer to drive the supercharger, too. Other systems have separate belts that get power from the crankshaft from a grooved harmonic balancer or their own secondary crankshaft pulley that mounts forward of the stock pulley. These systems will also have a separate belt tensioner mechanism just for the supercharger. This tensioner will either be spring-loaded, to provide the correct tension automatically, or it will be manually adjustable where the tension must be set by hand according to the instructions provided with the supercharger kit. (For the manually adjustable ones, check the belt tension periodically and reset to the correct amount if needed.)
Excessive belt tension places additional stress on the belt and bearings and can also lead to metal fatigue on the supercharger and crank shafts. Manually increasing tension over the suggested amount to resolve a slippage issue should be done only as a last resort. Spring-loaded belt tensioners are usually not adjustable – if one of these systems is slipping it may be an indication that the tensioner has worn out and can no longer keep the belt from slipping. A worn-out spring-loaded tensioner may also be unable to prevent the belt from jumping off the pulleys during hard shifts or deceleration and should therefore be replaced immediately once identified.
Inspect the belt periodically for abnormal wear or if the belt is beginning to squeal during acceleration. A slipping belt may show signs of black dusty buildup on the bracket or brace near the supercharger pulley. Replacing the belt to resolve a slippage issue should be done if the tension has already been verified to be correct. The Goodyear Gatorback Poly and the DayCo Poly Cog provide superior grip and durability over conventional V-belts. Installation of these belts resolves slippage problems almost 100% of the time.
The rotors or impeller of your supercharger have a faster rotational speed than any other mechanical part on your vehicle. The bearings and seals are built to withstand speeds exceeding 40,000 RPM (in the case of some centrifugal superchargers)! These parts are also more precisely balanced than any other rotating part in your vehicle. Identify the oiling system on your supercharger. Some systems are lubricated with engine oil that is fed from the oil pump. These superchargers take more time to install initially and may require tapping into the oil pan. However, once installed they are essentially maintenance free.
Other systems have their own oil reservoirs for self-contained lubrication. These superchargers offer installation convenience but they do require extra maintenance. Refer to the instructions from your supercharger kit for the proper oil grade selection, filling methods, and change intervals. Supercharger oil should be checked at least as often as your engine oil changes. Maintaining the recommended oil level is critical since it serves not only as lubricant, but also as a coolant for the bearings and gears. Overfilling the gear case will cause overheating and damage to the seals. Low oil levels will lead to premature bearing and gear wear.
When it comes time to change the oil in the supercharger, you may find it looking as clean and new as the day you installed it. Since the supercharger oil does not pick up any combustion byproducts, it generally stays fairly clear. It does, however, pick up micro-contaminates and should always be changed at the suggested intervals regardless of how it appears. On some supercharger systems, you may find that the drain plug is located in an inaccessible place on the supercharger housing. In these cases, if possible, a dip tube can be constructed from a length of small-diameter tubing and used with an oil-trap jar to vacuum or siphon the old oil out. This method is especially useful for Whipple systems on GM 5.7L Vortec engines. (Never insert any tube or object into the gear case if the engine is running).
There are quite a bit of points to consider when running a supercharger on your engine. Aside from their technical aspects, superchargers are supposed to be fun. Doing your part to properly maintain your engine and
your supercharger will ensure many fun-filled, supercharged days ahead!