I cant find the recommended preload for Morel lifters? I am asking in here cause I've seen CStraub and other experienced with Morels in here. Thanks.

Charlie

 

.030-.020"

 

Thansk. Time to go remeasure and adjust p rod length as necessary.

 

.030 to .040"

 

CStraub, thanks...I was wondering if you hadn't slipped off the site...*wipes sweat from brow* I appreciate it. While your here, if you look back here, how is this for checking length...
Remove rocker arm and pushrod
Rotate the engine until both valves are closed? Or is until one valve is mid-lift and check opposite valve?
Insert Checker
Torque Stock Rocker to 22ftlbs
Adjust Checker until there is zero lash, and then add in Morels recommended pre-load + .010" for growth while hot of Aluminum block/heads.

So, in this way, insert checker, zero lash, measure it, we'll say 8.000" add in the .040" (morels pre-load) + .010" (growth) = 8.050"? And of course use overall or oil hole drilled measurement.

Also, is it better to run the high (.040") or low side (.030") of pre-load, what effect might there be?

Charlie

 

I thought it was .20 - .60. that is what lunati's web site says, and they are 'supposed' to be the same thing.

 

Ive always heard .030, whereas the stocker like .080 - .110

 

Some people probably swipe their brow when I leave. Anyway. Yeah what you are doing work. More preload less power. The negative. . .tend be a little noiser.

 

Why would more preload make for less power? Because its got an extra 5# of spring to compress? How about considering the fact that more preload means less oil in the lifter which means less weight which makes for a lighter valvetrain.

 

That microgram of oil wt is not even a consideration for mass vs energy. Thats like arguing against using a 3/8" .135" wall pushrod, which is what I will be swapping to as the 5/16" .080" wall are really not up to the task. Feel free to reference Phil99vettes post in internal section on how his 7.8+ prods held up. Mine are longer at 8.100".

CStraub, thanks again. Will get this done hopefully before I ship the car back to the mainland. I will also check the swipe across the valve tip.

Charlie

 

Guitsboy,
I am no engineer but it has something to do with the high pressure area/ chamber in the bottom of the lifter. Hyd. lifters came up in conversation on my back deck during the NHRA race with Ed Morel. He would not go into detail but they happen on something with the valving of hyd lifters and amount of preload and the power loss it causes. The next generation hyd will be out around August and the pre-load will be minimal but the rpm potential will be much greater and for continuous durations of 15 to 20 minutes at the upper rpm.

 

Very interesting. The way I picture it in my head, more preload seems like it would shore things up and snap the valve open quicker because with more lifter spring pressure, theres less force bleeding the lifter down. Perhaps it has to do with geometry instead? I dont know, but ill definetly look for info on the new lifters in a couple months. Seems counterintuitive, but that makes it all the more fun to read up on... Thanks for the info.

 

A bit of trivia. . .care to guess the hyd PSI in a std hyd roller lifter at 6500 rpm? Just take a stab.

 

Im gonna take a shot and say around 2500 psi. Figure a dual spring at 350# of open pressure against a plunger that looks to be about 1/6 of an square inch at max lift. That would account for 2100 psi right there. Then add on another couple hundred psi just for accelerating the inertia of the pushrod, the rocker, the valve, the retainer and atleast some of the spring. Just a shot in the dark.

 

Try 36,000#'s.

 

But if youve got more preload, that little spring is gonna cut that down to 35,995# Damn, thats a lot.

 

One problem with the OEM lifters is body distortion at upper rpm levels because of this pressure.

 

Less preload also makes more power due to the longer duration and more lift, but the biggie is when the lifters go into "pump up", which is what happens when something in the system causes a gap in the system that the lifter has to take up, so it stays pumped up and holds the valve open, and then power goes down.

Bret

 

Okay...I am also double checking my pushrod length soon.

Iron block, aluminum heads.
Lunati/morel lifters.
Just to clarify...zero lash is when there is no play in the pushrod correct??
Take that number and add 040" for pre-load and pump-up.
Sound right?