PROFESSOR OVERDRIVE ® Professor Overdrive and Summit’s team of tech experts are hard at work in the lab solving your muf er mysteries, radiator riddles, and piston predicaments! Gather your vehicle’s make/model/year, engine, transmission, and driveline details, and send your tech questions to: Ask Professor Overdrive c/o Summit Racing Equipment PO Box 909 Akron, OH 44309-0909 Visit the online Help Center at SummitRacing.com, where you can browse our technical resource archives and ask questions. Still need help? Call 1-800-230-3030 to speak directly with one of our knowledgeable sales experts. 248 WARNING: For Proposition 65 information, see p. 189 Some parts are not legal for sale or use in California or other states with similar laws/regulations—see p. 189 for details. Choosing the Correct Fuel Filter Tiny particles of dirt and contamination in your fuel system can damage injectors, carburetors, and electric fuel pumps. Choosing the correct fuel fi lter (or fi lters) is critical to protecting sensitive fuel system components and maintaining adequate fuel fl ow and fuel type compatibility. Fuel fi lters are designed to capture particles too small for the naked eye to see. The ef ectiveness of a fi lter is measured in microns, which is the size of the particles that it can reliably remove. Micron ratings range from 2 to 100, with smaller numbers indicating better fi ltration. However, choosing a fi lter with the smallest micron rating is not always the optimal choice, depending on its location and the type of fuel system you have. The wrong fi lter in the wrong position can cause a pump to work harder, leading to premature pump failure or fi lter clogging. It’s best to follow the pump manufacturer’s fi lter recommendation, consider your specifi c situation, and use a fuel pressure gauge to monitor the system for pressure drop. Filtration Range 100 Micron Filters are usually used as pre-fi lters to protect fuel pumps and keep larger debris from clogging your post-pump fi lter. They can be mounted in-line before the pump or in the tank. Pre-fi lters in the tank are often called sock fi lters or fuel strainers. 40 Micron fi lters are generally used for carbureted engines after the fuel pump. Utilizing a 100 micron pre-fi lter with a mechanical fuel pump is still advisable. 10 Micron Filters are typically used after the fuel pump on fuel injected engines and must be paired with a 100 micron pre-fi lter. Filter Material When choosing your fi lter’s element material, consider fuel compatibility, reusability, and its location within your fuel system. Paper Filters are often referred to as cellulose fi lters and are usually disposable. They should not be used with methanol or fuels containing more than 20% ethanol. Stainless Steel Filters are compatible with all fuels and can typically be cleaned and reused. Sintered Bronze/Microglass/ Fiberglass Filters are for post- pump use only and are generally non-cleanable. Turn to page 37 or visit SummitRacing.com and search “Fuel Filter” to fi nd the correct fi lter for your system! THIS EDITION: Fuel Filter Facts and Clutch Classifi cations Find more helpful tips from the Professor in these sections: AIR AND FUEL: External Fuel Pump Mounting PLUMBING: AN to Inch Conversions CAMS AND VALVETRAIN: Flat Tappet Cam Lubrication For handy tech articles, how-tos, and product installs, check out our blog at OnAllCylinders.com! COOLING: Short vs. Long Chevy Water Pumps TRANSMISSIONS: Finding Converter Bolt Patterns WHEELS AND TIRES: Buying Custom Wheels What’s the Difference Between Borg and Beck, Long, and Diaphragm-Style Pressure Plates? A clutch pressure plate is a spring-loaded plate bolted to the engine’s fl ywheel. It applies clamping force to the clutch disc that is splined to the transmission input shaft. When the clutch pedal is depressed, the throwout bearing is pushed (or pulled, in some applications) against the plate’s fi ngers, compressing the springs and releasing the clutch disc from the engine’s hold. When the clutch pedal is released, the clutch disc is squeezed tightly between the pressure plate and fl ywheel, engaging the transmission to the engine. This enables the engine to transfer power to the transmission during acceleration and gear changes. Various pressure plate styles are available, depending on the make and model of your vehicle. Here are three common types: Borg and Beck Borg and Beck pressure plates are commonly found on older GM, Mopar, and some AMC models. These pressure plates use multiple coil springs actuated by three 1" wide levers to engage and disengage the clutch. Borg and Beck pressure plates clamp the disc with a fi xed amount of pressure. Long The Long-style pressure plate is commonly found in older Ford muscle cars and trucks, and is the basis for many modern drag race clutches. It has 3 levers that actuate multiple coil springs to engage and disengage the clutch. The levers are weighted and provide additional centrifugal force as rpm increases. This adds static pressure to the coil springs and helps the clutch hold more power. Diaphragm A diaphragm-style pressure plate is commonly found in late model vehicles and as an upgrade for both previous types. The diaphragm pressure plate utilizes a one-piece Belleville (or diaphragm) spring. The Belleville spring allows for a relatively light pedal ef ort and smoother engagement compared to both the Borg and Beck- and Long-type pressure plates. Want to learn more? Or need help in selecting the proper clutch or fl ywheel for your setup? Scan here with your smartphone!
