Dumb question about lifters and preload
Dumb question about lifters and preload But the way hyd lifters work can you really set preload on em. I mean all you are doing is pushing the plunger further down into the bore of the lifter, so what are you actually preloading. Moving the plunger down in the bore can poosibly cause high rpm pump up...
With the stockers, no preload setting necessary. Just torque to 22 ft Lbs. On other aftermarket hydraulic lifters, theyre more robust and the spring inside is much stiffer. Setting the preload will push the plunger less distance than with a stock lifter. Conversly, torquing to 22 Ft Lbs may not be enough proload on a stronger aftermarket lifter. Or atleats this is my understanding of it.
Originally Posted by GuitsBoy
With the stockers, no preload setting necessary. Just torque to 22 ft Lbs. On other aftermarket hydraulic lifters, theyre more robust and the spring inside is much stiffer. Setting the preload will push the plunger less distance than with a stock lifter. Conversly, torquing to 22 Ft Lbs may not be enough proload on a stronger aftermarket lifter. Or atleats this is my understanding of it.
If im understanding him correctly, he's saying that you would have to start with the stock cam and valvetrain. Tighten till you can no longer twist the pushrod with your fingers, as this is zero lash. Then count the degrees to get to 22 ft. lbs. Then when you do your cam and valvetrain swap, tighten rockers to zero lash, and then add the same ammount of turns to the rocker bolts. Thats basically your procedure, DAPSUPRSLO, no?
I dont necessarily agree with that, and this is why. When you start to tighen the rocker bolt, you get to zero lash before the rocker pivot has seated home in its base. By the time youve torqued it to 22 ft. lbs, the rocker is fully seated. Tightening it past 22 ft lbs should not increase the preload on the lifter because the rocker is already bottomed out against the base. further tightening will not bring the rocker further down since its already seated. The same should hold true with an aftermarket cam and pushrods. Once the rockers seat, tightening should not increase preload on the lifters. The only way to change the preload is to measure the differenes in base circles and compensate with different pushrod lengths.
Setting preload on aftermarket lifters really needs to be done using adjustable rockers in order to set the correct preload, otherwise you only get the preload that your pushrod length gives you and thats it.
I dont necessarily agree with that, and this is why. When you start to tighen the rocker bolt, you get to zero lash before the rocker pivot has seated home in its base. By the time youve torqued it to 22 ft. lbs, the rocker is fully seated. Tightening it past 22 ft lbs should not increase the preload on the lifter because the rocker is already bottomed out against the base. further tightening will not bring the rocker further down since its already seated. The same should hold true with an aftermarket cam and pushrods. Once the rockers seat, tightening should not increase preload on the lifters. The only way to change the preload is to measure the differenes in base circles and compensate with different pushrod lengths.
Setting preload on aftermarket lifters really needs to be done using adjustable rockers in order to set the correct preload, otherwise you only get the preload that your pushrod length gives you and thats it.
you just mis understood me. We are on the same page. Another way to adjust preload on the stock rocker system is to add shims. Basically with stock rockers you can add shims or change pushrod length to change pre load values. You could also change valve stem length or cut down your rocker pedastools. This is all assuming it does not through off valve train geometry.
Trending Topics
I wish I had time to type a lot and teach class. Most don't undersatnd what is going on. All I can say if you want to know the correct info and proper method...call me.
1-800-365-9145 ext. 558
Thanks,
Brian
1-800-365-9145 ext. 558
Thanks,
Brian
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
Originally Posted by Unaffiliated Racing
I wish I had time to type a lot and teach class. Most don't undersatnd what is going on. All I can say if you want to know the correct info and proper method...call me.
1-800-365-9145 ext. 558
Thanks,
Brian
1-800-365-9145 ext. 558
Thanks,
Brian
TECH Enthusiast
Joined: Dec 2003
Posts: 535
Likes: 0
From: Warner Robins, GA
Originally Posted by Unaffiliated Racing
I wish I had time to type a lot and teach class. Most don't undersatnd what is going on. All I can say if you want to know the correct info and proper method...call me.
1-800-365-9145 ext. 558
Thanks,
Brian
1-800-365-9145 ext. 558
Thanks,
Brian
<------dials number...
Brian told me the difference between lash and preload, which i didn't know.
He also told me why people buy adjustable roller rockers and the amount of preload they work with. For my cam install, i'll drop in the 7.400 pushrods, torque my stock to 22 ft/lbs, and go about my happy way.
Thanks Brian!
Brian told me the difference between lash and preload, which i didn't know.
He also told me why people buy adjustable roller rockers and the amount of preload they work with. For my cam install, i'll drop in the 7.400 pushrods, torque my stock to 22 ft/lbs, and go about my happy way.
Thanks Brian!