lifter preload with GN1 alum heads....different than irons?

[turbonut85]

I'm just wondering if there is a common practice of putting more preload in hyd roller lifters when installing them on alum heads vs a set of irons? I'm running comp rollers with the afore mentioned GN1 heads and T&D shaft mount rockers...I set them (cold on the stand) at the point of no more up/down movement in the cup, plus 1/2 turn....and they are noisy as hell...and they get noisier when the car gets warm... should they have more preload with the alum head since they would theoretically have more heat expansion than irons?? Ant input is greatly appreciated. ---Keith

 

[whitehot1]

I can't answer your question about iron heads,but.

I have the same setup as you; GN1 heads, T&D shaft mounted roller rockers, Comp roller lifters. I also set the preload on the stand like you did except i took them to 3/4 turn. I'm using the 853 lifters and they are quiet both cold and with the engine warmed up.

 

[turbonut85]

I'm thinking 1/2 turn was not enough...do you happen to know what length pushrods you have??

 

[SPOOLFOOL2]

Typically, with alum heads, you'd run about .010" more preload on your Hyd rollers than you would with irons. T@D rocker arms adjust .050" per turn. Sounds like you've got em set at about .025". I'd try them at 3/4 to a full turn. This should get them to about .040-.050"preload. If that doesn't quiet them down, switch to Morels.

Happy Spooling.

Mike Barnard

 

[whitehot1]

I'm thinking 1/2 turn was not enough...do you happen to know what length pushrods you have??

I don't remember the length of the pushrods off hand,i have it written down in my notebook i'll have to look through it.

I used an adjustable pushrod checker to get the length i needed for my engine. I would recommend you do the same to ensure you get the proper length pushrods for your application.

 

[ek02]

What Comp lifters do you have? The 885 is supposed to be set at zero lash, the 853 is preloaded. If you have 885's, adjust them to zero lash to 1/8 turn on the stand, and then adjust them hot with aluminum heads to zero. I use a .002 feeler guage to get them close to zero when hot, then tighten 1/8 turn. The heads grow a little when hot. If your cam has some fast ramps, any roller lifter may be a little noisy.

 

[turbonut85]

I measured the pushrod length with a checker...so I'm confident I have the correct pushrod length...but I will measure them again. I ran this cam/lifter combo in my last build (with stock rockers) and it was no where near this loud. I will try to check them when hot....pass side is gonna be tough to do though....(hot air has the dp and up pipe in the way) ....I know, I know.....hot air.

 

[usetaboost]

For as long as it will take you to get to the passenger side, you'll have to do it one side at a time. I'm betting you have plenty of practice tearing it down by now though lol

 

[EVIL]

If that doesn't quiet them down, switch to Morels.

My Morels were noisy from day one. I readjusted them probably 10 times with anything from a half turn to about 10% past a full turn on harland sharp rockers. Irons heads. They never quieted down. Luck of the draw I guess.

D

 

[turbonut85]

For as long as it will take you to get to the passenger side, you'll have to do it one side at a time. I'm betting you have plenty of practice tearing it down by now though lol

that's no BS.....think of how hot that dp and up pipe are gonna be.....ugh.

 

[EVIL]

I remove the passenger side motor mount bolt and jack up the engine with a block of would. It makes it easier.

D

 

[usetaboost]

I think you should just do the driver side and that way only the passenger will have to hear the clacking lol

 

[usetaboost]

You could always adjust them with it running. A little oil never hurt anything

 

[turbonut85]

You could always adjust them with it running. A little oil never hurt anything

I wonder how much fun that would be....engine running and exhaust blowing straight in my face directly out of the pass side header....

 

[EVIL]

You could always adjust them with it running. A little oil never hurt anything

That would interesting to see.

D

 

[mikemcvaney]

My Morels were noisy from day one. I readjusted them probably 10 times with anything from a half turn to about 10% past a full turn on harland sharp rockers. Irons heads. They never quieted down. Luck of the draw I guess.

D

What size cam?

 

[EVIL]

212/212

D

 

[turbonut85]

So I finally got some time to deal with this....popped the driver side valve cover...1) it seems the rockers that are on base circle have quite a bit of lateral movement...is that normal?? Also, here are a couple of pics of the tracks on the valve stem and of the rocker adjuster....it seems to me that I may need longer pushrods...?? Thoughts??

 

[turbonut85]

Here is a shot of the pushrod I'm running...

 

[turbonut85]

Any opinions??