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shimming pedestal rockers

4825 Views 6 Replies 4 Participants Last post by  TALONS
Hello Gents

I was helping my son put the top end of his motor together last night. He was trying to shim the pedestals on his 86 5.0.

Long story short... I noticed some lifters would not collapse for the preload - it compressed the spring instead? I took his used lifters out ( he didn't have $'s to get new ones )- they looked like they were varnished and the piston did not move on many of them. Some I could compress. I had asked him to soak them in oil last week- he did. Some of these lifters - the plungers just don't want to budge.

He is buying new lifters - gotta have them.

anybody have any benificial experiences they would like to share that would help us get through this?

the block has been decked .01 and the heads milled .010-.015. I looked at rocker arm contact patch - looks ok

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The lifters will bleed down after a while. I have seen this many times when reinstalling rocker arms. Some cars are alittle hard to start until the lifters bleed down and readjust themselves after starting. If yoy are real concerned, you could take the lifters apart, clean and reassemble.
I shoved a pushrod in the cup and tried pushing the plunger down - some will not budge( would rather compress the valve spring with 145 seat pressure ). Some are real easy to move the lifter plunger and you can see oil bleed out of the hole.

We have new ones coming. I would think the oil would bleed out of the hole as opposed to compressing a big valve spring

thanks jim
I used to put old lifters in the vise and bleed the oil out of them. It took a lot of strength and time to get them depresurized. Why did I do this you ask. Because prior engines had a very hard time starting due to lack of compression because the valves would not close all the way. I even had my boss tell me I put the timing belt on wrong causing the low compression. Nope. After cranking the crap out of the engine for a half hour it finally started and ran well. I even had some cars after reinstalling the valvetrain that I had to back the rocker arm nuts loose to get it started and then retighten slowly after it started. These were non adjustable valvetrains. All cars had no problems after starting and the lifters readjust them.selves
Hey there, I "rebuilt" every one of the lifters in my Roller engine. I made a mistake on priming the engine too long. When i started to adjust the rocker arms , sure enough if half of them didnt push on the springs instead.
Your lifters arent bad. Save some money. They dont ever need replacing unless theres an issue with the needle rollers or the big roller itself.
On 2006-03-10 14:36, Blue Fastback wrote:
Because prior engines had a very hard time starting due to lack of compression because the valves would not close all the way. I even had my boss tell me I put the timing belt on wrong causing the low compression.

Same thing happened to me on a couple different occasions. Both were on the same 2.3 4 banger. First time, I had just put a ported head on---no compression on #2 and #3 cylinder. Figured I did something wrong with the head gasket & yanked the head back off. Put it back, same thing...only this time I got "smart" and compressed the HLA's (hydraulic lash adjusters...fancy name for "lifter" ). Fired right up & idled great.

Later on after changing turbos I noticed that it would get REALLY loud and start missing above 5500 RPM. First thought was bad HLA's. So I put a new set of HLA's on it and it ran like a raped ape.

Just some food for thought, FWIW. Sometimes the relief won't collapse when it's supposed to. I guess in your case, they can just be taken apart and cleaned with diesel or Kerosene...seems to work pretty good. I didn't mess with the HLA's taking them ahead to just replace the things as they were only like $1.50 each from where I was getting them.
Thanks guys

My son had already bought a set. His old ones - after looking at them - were pretty nasty on the O.D. You could see and feel galling on those surfaces. I have an extra set that I am going to take apart and save and modify a pair of the "ugly" ones( turn'm into solids) for valve train moc-up

Here is an interesting thing I found on the web. See if you can find Buddy Rawls website and there is a section on misconceptions, or something like that. It talks about how preload is not really a good thing for racing. you can even set it to 0 preload or, i believe, a tight .002-.003 lash!

That was a good set of articles

Oh by the way - I had aleady shimmed to .02 preload by the time I had read this article. Engine started right up.

Thanks again
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