Hey Guys,

First of all let me state that I am not having problems I just want to know something.

What effect does more or less preload have on valvelift?

With a Solid cam more Lash equals less valvelift.

If I run less preload on my lifters will I get more or less valvelift?

Thanks in advance!!!

Brad

 

Neither.... Solid is just that.. a solid lifter so the more lash, the more the lifter has to move to make contact with the valve to start it moving. Preload is just that. The valve, lifter and pushrod are all already touching. Youre just adjusting how much tension is on the inside of the lifter.

 

Thanks Man. That leads me into my next question.

What effect does changing the preload have on tuning?
The only reason I ask is because I have heard some say less is better.
Mine are set 1/4 turn past zero lash. I want to put a dial indicator on them and set them @ .004" preload. If not .004" I want to make them all the same.

I don't want to waste my time with it if there is absolutley nothing to be gained. Just need some help before I do this.

Thanks again!!

Brad

 

Comp R's are supposed to be set-up at 0-.004" preload. Any more than thet could be detramental to the lifter, says Comp. I ran mine at 1/4 past and never had any problems, but it did seem to run better when I had them set-up at zero. I doubt pre-load will have any effect on your tuning at all.

 

Comp Rs are supposed to be set at .008-.010" past zero lash...Call the tech line.
Mine are dead quiet set that way

 

I had mine set up at .004 had had major problems. I have them now at .010 with no problems.

If the preload is too tight you will have problems as it cause the lifter to go flat and not work, too loose and it gets sloopy and breaks things.

 

Thanks Guys! Guess I will leave them alone.

Brad

 

I am having problems with mine right now, so much to the point that I am considering pulling them out of the motor. On the dyno my car falls flat on its face at 5200 rpm and the MAF readings go real bad to indicate valve float. It's gotta be the lifters, we checked the springs today and we got the same problem again. Lifters were set to 0 preload, any suggestions?

 

Are you running adjustable rockers? They need to have .008" to .010" preload.
I have heard of some running less than that. Thats why I started this thread.

What camshaft are you running? What Springs?

Brad

 

I am running adjustable rockers (comp pro mag 1.7) They were set to be around .006 when hot. i'm running the Futral F11 (228/230 .581/.591 112) with Crane dual springs (think they are the crane 3030's.) Allan at Futral took time Thursday to help me out with it, we shimmed the springs believing that was the problem, but sure enough it is the lifters. I am pulling them out ASAP and putting the stock ones back in.

 

Let me know how it goes if you dont mind.

Brad

 

I would tighten up the preload some and try it again. Ive had zero problems with 2 sets Ive had. I did have to use a heavier than reccomended preload. With Comps .004, I had massive problems. I have also heard that the Pro Mags have some issues also. Ive seen a few selling them because they had bad experiences.

 

.006 preload hot is incorrect is and probably a source of your issues. .008-.010 cold is recommended. You mean 1.75 Pro Magnums too...I dont think they make 1.7.

 

Yeah, I guess they are 1.75's. See, I just got the car not long ago and when I went to Futral it was to get the rockers pulled off and the set of stockers put on so we could see if that was the problem we were having on the dyno. We soon found out that my heads have the 11/32" valves, which means stock rockers wont fit it, so I am in the same situation.

 

This thread pertains to this towards the end...