The Stovebolt Site Forums The Shop Area Engine Shop 235 issues, again

good day everyone, i was checking my valves a couple days ago and i noticed whoever rebuilt the engine didnt adjust them properly, and they were all the way tight! a couple valves were sticking open even. it ran but poorly and it sounded funky, which led me to check the valves.
and im glad i did. anyway, ive seen everywhere that a valve adjustment cannot be done cold. does anyone know why? is it something to do with the lifters? because when i went to adjust them and pushed down on a rocker the push rod sank a good centimeter off the valve rod!
usually when a lifter sinks it means its bad but because the engine only has a total run time of maybe 1 hour since its restoration a couple months ago, im not sure whats up with it, they are hydraulic and i know theyre variable but i dont think they should just sink down like that.

1951 chevy 3100 1/2 ton pickup with 1954 235 engine (installed sometime in the 50s).

it was overbored .080 if that helps

i have a easy way to heat it up, granted if the engine runs right. i have it face first in my garage so there isnt much fresh air flow, so it should get up to temp. and because my temp gauge isnt installed yet, ill just watch the top hose temp with a infrared thermometer, granted the engine runs after my "adjustment"

Hy Mr. Dane, valves can be adjusted cold for an initial startup, but adjusting them after the engine has been brought up to temperature and allowed to normalize will give you an adjustment closest to specification. Hydraulic lifters are much more forgiving in their adjustment, once all the clearance is gone between the components then anywhere between a half and one turn down will set the plunger in the "middle" of its travel, hope that helps.

It seems that whomever did the "restoration" shouldn't be allowed anywhere near a tool box if he can't adjust valves properly. That makes the rest of his work highly suspect. What, exactly was done during this alleged rebuild?
Jerry

to be fair, whoever did the resto couldnt run the engine, but the two things i noticed he did wrong was paint over a oiled surface, but who knows, he may have not gotten to some of the cracks and crevices, and the valves, everything else is fine though, still dont know whats up with the lifter deal though..

what im saying is i go to adjust them, but when i push down on the rocker with a screw driver the push rod sinks down a good centimeter or so, im wondering if the lifters are bad already or what, because only a couple cylinders do this (3 4 and 5) at any given rotation (valves closed obviously) and i tried just not pushing down at all and setting it when it felt pressure, but then when i turn it over it wont push down on the valve at all. im gonna talk with my local mechanic and hopefully he can help..

ill try running it untill the water sits at 180 or 190 for a little bit, which shouldnt take long, as its nose first in the garage w/o a fan blowing into it, ill check them then i suppose.

Use a priming tool to develop oil pressure without running the engine and turn the crankshaft over slowly by hand. It sounds like the lifters were installed without pre-oiling them, and it might take a long time for them to fill so they can be adjusted correctly. An empty lifter has trapped air in it, which is why at least some of them can be compressed by hand. Stovebolt hydraulic lifters, particularly the ones made recently in some third world country, are notorious for being defective. There are ways to work around those problems, but there's nothing easy or completely reliable about it.

Air trapped in a hydraulic lifter is a common problem, and it is what usually causes them to be spongy.
Have a look at my blog post on this subject.

ill make sure to do that.

thats gotta be my issue. thanks for the tip!

I had this issue with a 235 with hydraulic lifter on a new rebuild. I set the lifters similar how solid lifters are adjusted in preparation for a 20 minute 2,000 RPM camshaft break-in.
It was noisy, but not much more than a 216 with a little too much valve clearance, and quieted down as it warmed up.
The key to doing this is to constantly twist the push rod as you tighten the rocker arm screw. Once you feel resistance in the push rod while twisting it, stop and tighten the lock nut.

"1951 chevy 3100 1/2 ton pickup with 1954 235 engine (installed sometime in the 50s)."

Has it been established that you have a mechanical lifter or hydraulic lifter 1954 engine?
I might have missed that pertinent statement in the posts, above. (I apologize, if this is stated, above.)

What is the engine serial number that is stamped into the block in the ledge to the rear of the distributor?

update: (a week ago) i loosened the clearance, let it run (it ran rough) once it heated i found that the lifters had filled up and i just made the adjustment and now it runs just perfect!

Sounds like a winner! Sometimes the KISS principle is the best approach!
Have fun!
Jerry