426 Hemi with stock rocker arms and Erson 278/370 solid roller cam. (238@.050 573/566 lift)

Machinist set lash .012/.014 cold. I've read as tight as .011/.013 hot is good, although cam manufacturers always seem to suggest quite a bit more.

So what is everyone running out there and does it make a difference running stock rocker arms vs A/M?

Depends on if they are cast or aluminum heads and or block. I have an iron block aluminum heads and a solid roller that calls for .020 hot on both. I set them at .012 cold. Crane general guide line is iron iron add .002 cold, iron Alum. minus .006, Alum Alum, minus .012.

Mike

Setting the valve lash can be done in many different ways, set with the piston on the firing stroke at top dead center, setting the intake valve when the exhaust valve rocker arm starts to open and then rotate the motor over until the intake valve opens all the way and start to close to set the exhaust lash. Some people, racers, shade tree and professional mechanics will remove the distributor cap and bump the motor over by hand so the rotor is pointing at the spark plug wire to each cylinder and set the valves that way
As already pointed out about setting the lash cold or hot will come into play depending on which head type you have, iron or aluminum.
I would start with cam makers suggestions on the lash and then experiment to see if you want and like them tighter or looser when hot
I use to run a 1970 Cuda in NHRA stock, it was very sensitive to the lifter preload, same thing on the 1969 Hemi GTX we raced before the Cuda, it was very sensitive the hot lash settings. We where running cheater cams that would check okay in tear down so they where not stock cams
On your roller cam it may want, or you may like it with tighter or looser lash, only you will know what you like and keep

Lash isn't something that is decided by popular vote. You set the lash per the spec provided by the mfg. That is really all there is to it. The mfg tells you what the lash is based on the ramp design of the cam lobe. Different lobes require different lash settings so you have to follow what the cam card says.

I prob should have wrote what I was really thinking lol Mind is going one way and not really getting it all down.

This is my first experience with solid roller and also with 426 Hemi. I've heard the stories about the needle bearing rollers coming apart and after quite a bit of reading and research it seems to be linked mostly to loose lash. Lash is either set too loose, or loosens over time and is not caught and ends up pounding the bearing out.

So, to be more specific, I was wondering who has had the most success running solid roller cam with stock rocker arms, and at what lash?

With the understanding that the cam makers lash recommendations are only that, recommendations for a point to start at, not necessarily to finish at.

Also with the understanding that you have clearance Everywhere to tighten the lash, and that you're not going to tight (power loss situation)

Hopefully that's more clear, and sorry for the confusion of the first post : (

From past experience, that is usually a "which came first, the chicken or the egg?" discussion.

Once the bearing is pounded out, of course the lash will open up for that reason only.

If the adjuster isn't found to be physically loose at the same time, then we would know the adjuster didn't loosen up
on it's own.

In the scenario I am referring to, the lash opened up because of a parts failure and no other reason
(which is much more common than the lash opening up first and parts failing afterwards).

If adjusters are coming loose on their own, then that's really the issue (not where the lash was set).

What brand and type/lobes are in this? If you know someone who has played with the lash a bit
on that lobe family, that's who you would really need to talk to.
What is the cam manufacturer's recommended hot lash?

Crane recommends .020 hot for my R276-420 and that's where I intend to start.....The lobe family
seems to be most commonly used in brand X circle track applications, I don't know of anyone else using
it in a Hemi, so I'll have to sneak up on it and find out. I intend to try looser up to .024 or so, and tighter down to .017 or so.

Well and there I go again! I wrote 50% of the #1 reason for needle bearing failures instead of what I should have written;

#1 reason for failures is lash set or left too loose Or too aggressive of a cam being used which should have been paired with bushed rollers vs needle bearing.

Regardless, great post and this was all I was looking for. If there was consensus on solid rollers living longer due to profile/ lash ect ect or not.

Working on a 30,000 mtr drives me to want to understand and be as sure as I can of every working aspect, even more so then the average mtr build, but knowing that many, don't even know where their cam is, even on a built Hemi, tells me that even the Hemi is looked upon just like any other mtr.

I'll go over what I've found and make a decision, but one things for sure, I will not run looser lash than cam makers recommendation, only tighter, knowing the mtr has all of the clearances to do so.

All the OEM 426 hemi motors that came with solid lifter had .032 lash, correct
I always tighten the lash up some( 10 to 25%)on all the loose lash cams I have used in my motors and recommend it for customer motors also
What rocker arms and camshaft are you using? What is the recommend lash ?
If your using all new valve train parts they will wear some after start up and breaking in, that will add clearances on the lash, once all the parts are broken and seated the lash should stay where you set it
If it doesn't there is a reason for that, abnormal wear or parts failing
Good luck on your deal

What Andy said..

All the info is in the first post. After a little more searching around and talking to guy at Erson cams going to run with the 12/14 lash is has right now : )