• Clearance Items
• Instructions & Tech Articles
• Dyno Build-ups & Tests
• Customer Rides
• Dealer Locator
• Customer Service

Find Your Part: Search OR

Return to Parts List Category : W2- Wedge World Tech HUG WEDGE WORLD TECH A19 TECH INFO ABOUT HYDRAULIC LIFTERS $0.00   WEDGE WORLD TECH From Hughes Engines  Dedicated to bringing news And truth to wonderful World of Mopar wedge engines   Issue #19 Hydraulic lifters Originally, 100+ years ago, all engines had mechanical, solid lifters. Hydraulic lifters were developed in the late 30's (1930's for you techies) for luxury cars like Cadillacs and Lincolns to make the engines quieter, and that is still the reason for them today. But hot rodders, in their quest to "have it all," want the performance of a mechanical (solid lifter) cam, but with the silence of a hydraulic cam/lifter. The original hydraulic lifters in cars such as your grandfather's '55 Chevy  would "pump up," that means "grow in length," if you kept your foot in it too long. That meant it held the valves open and the engine quit running. Duh! Eventually the lifters would bleed down and the car would start and run fine - prayers answered! The hydraulic lifter industry saw a market for "anti-pump up" lifters and so most lifter manufacterers developed and sold lots of high rev hydraulic lifters. Now the hot rodders, in their quest for a hydraulic lifter that worked like a mechanical lifer but was quiet like a hydraulic, found out that if you reduced the pre-load you could turn more RPM before the lifter pumped-up. However, the minimal pre-load and high RPM tended to push the lock ring out and the lifters would come apart. That usually cost a lot of money to fix - a whole lot! So what is the correct pre-load on any hydraulic lifter? It is my favorite word - TRADE OFFS. The more pre-load, the higher the RPM and the noisier it gets. Is it worth it for a few more RPM - your choice. Or get a mechanical (solid) lifter cam and ou won't have to worry about it!