235 Chevy valves- Why don't they stay adjusted?

[raven]

Well folkes,
Most of you know that I just rebuilt this engine (1958 235 Chevy six) in my '54 and I adjusted the valves before startup. After the initial break-in, I adjusted them again when I re-torqued the head. I then ran it for about 120 miles and the valves were so far out of adjustment after that, that on popped loose. I re-adjusted them (on the side of the road) and it ran fine and sounded great. Well, that was last week and Saturday I ran to pick up the 'T' touring back half that Fatasswhitewalls had and the valves were so loud that I knew I'd need to run them again. Sunday I took the vavle cover off and adjusted them once more. Some of them were scary loose. Today on the way into work, they ae starting to sound loud again. I am to the point that when I set the lash, I'm really putting the torque to the locking nut in hopes that they will stay right for a little while longer. Do I need to put lock-tite on the locking nuts?
Do I need to put locking washer on the adjusters?
Does anyone have any experience with similar problems?
If I have to keep this up. I'm tempted to put the Buick 215 in it...
r

[Unkl Ian]

Is the 235 valvetrain like the SBC?Stamped rockers?As I remember,the stock nuts on the SBC do not turn freely.They are squeezed out of round to create a locking effect on the stud.If the nuts were worn to the point that they would turn freely,they wouldn't hold the setting.

[brjr51]

I've never had one where the screws and lock nuts come loose. I've seen the threads on the screws go bad,maybe check that. You're not wipin' out the lobes on the cam or lifters are ya? Have you checked for metal in your oil? I seem to recall you're not supposed to run factory lifters with an aftermarket cam or vice-versa. Something about the different type of iron used in factory cams.

[raven]

I just changed the oil yesterday and didn't look to see if there was anything in it.
I guess i'll run until this weekend and change it again to see if something is there.
If that's the case, what would wipe out the cam?
I've been babying this thing since the rebuild and changing the oil often just to take care of it.
r

[safariknut]

Don't have a whole lot of experience with inlines but some things to consider:
Are the locknuts backing off or are they still tight when you reset them? If they're loose,I would replace them with new ones.If they are NOT backing off,then there is something wearing and causing the excessive lash.I would then suspect incompatibility between the cam followers and camshaft.You also didn't mention what you were setting the lash at;if it were set too tight it might cause excessive pressure between the lobes and followers or it could bend the pushrods.
Rather than use Loctite I would consider setting the valve lash and then "staking"the locknuts by using a center punch and hitting it at the juncture of the locknut and the thread.Just enough to keep the nut from turning but still allow it to be turned with a wrench.JMO

[raven]

The first time I re-adjusted them, they were very loose. This last time I didn't notice that the lock nuts were loose, so based on that, it seems that I've got a lot of wearing going on. What would cause that?
I'm setting the lash at factory specified lash.
Intake: .008
Exhaust: .016
r

[mr57]

Are you getting enough oil on the top end along the rocker shaft? no dry spots? Didn't bypass the oil filter? You could be losing lifters if some of them are dry on the top end. I had that probl;em once. Also, the lock nuts can loosen up if not tightened. I had one thread it's way right out once.

[raven]

She's wet on top.
I tightened the crap out of them.
Didn't by-pass the oil filter.
r

[brjr51]

I've never tightened the nuts past a good snug. Shouldn't have to bear down on 'em. Lash clearance(.008-.016) is good.Usually if you bend a pushrod,it won't run worth crap and you don't bend 'em all unless maybe you've got super stiff springs.If the nuts are tight the next time you check it's almost got to be wear.The screws can't move if the nuts are tight and the lash won't change.Check the valve ends of the arms to see if they show unusual wear too.

[brjr51]

Forgot to ask,what kind of cam do you got in it?

[Smokin Joe]

I put about 50k miles on my old 57 pickup. Never touched the valve lash after the first time.

[porknbeaner]

School me here someone. Did the 235 have stud mount rockers?
If they are does this particular motor have screw in studs or the press in studs that GM is so famous for. If they are press in studs they are probably pulling out causing you to loose adjustment on the valves.
Just a thought.

[raven]

The short block is all stock (picked it up from Jim Carter's) with a stock cam and lifters.
One point of interest was the old motor (a '55 vintage) had hydraulic lifters and this one (a '58 vintage) Cater's gave me solid lifters.
Is that right?
r

[Rocket88]

.008 and .016, are you setting them hot or cold? Did you repalce the rockers themselves? I'm also curious about the end that sits on the valve. My bro's 50 had a couple rockers that kept slacking off. We touched up the rocker ends and changed the adjusting nuts, it cured his problem.
.008 is a little too tight for my liking, I usually set them at .012 and .016 hot.

[raven]

That's the factory setting hot.
that's what I'm doing.
I replaced the shafts and a couple of the nuts and ends that fit on the pushrod end, but other than that, just new valves.
What would cause excessive cam wear?
r

[Kustm52]

This is a new motor, right? Did you break the cam in properly before starting driving it??

Brian

[mr57]

I was thinking the same thing about the cam. Did you prime it? Any sort of assembly lube used? The rocker balls aren't worn to a point anywhere where they meet the pushrod?

I did have a 235 once that had seven lifters collapse on it in less than 50 miles during breakin. They were just bad lifters, though. Swapped them out and as far as I know the motor is still running fine 17 years later.

[raven]

Primed the engine several times before and after I installed the head. Right before I installed the lifters, I lubed the cam lobes. I primed the engine again. Shortly afterward we got it started. Ran it for a short while (3-5 min.) then shut it down due to a mysterious 'noise' from the crank area. Fired it up again and ran it for a short time (5-6 min.). Dropped the pan and checked the torque on all the rods (fine) buttoned it up and new oil. Fired it up again (3-5 min.) shut it off.
Went to get cleaned up.
Hour later got in it and ran the KCSP all day.
Did I screw up the cam?
r

[Zodoff]

Looong pushrods on those.. Easy to bend...

[Roothawg]

I THINK that you can put solids in any block but not vica versa. Is this right?

Also...not to insult your intelligence but did you have new cam and lifters? I see where you bought the short block and you said stock cam and lifters...just making sure you didn't reuse the old lifters and move them to other holes.That will kill a cam in a matter of minutes.

[Kustm52]

Root, you are correct. 235 hydraulic lifters are fickle sumbitches...I had two or three that started ticking after just a few thousand miles. Put in a whole new set...usually when cranking cold at least one ticks for a few minutes. I read somewhere that the new ones don't have something correct, seems like one oil hole is too small or somehting...supposedly Patrick's has ones that are correct. I just put up with the ticking...only does it when cold and not always then. Raven, if you are expecting the valves to be quiet when adjusted properly, they won't be... my grandad ( who was a chevy mechanic first certified in '47, and taught me a lot!) said if you can't hear them, they are too tight....I'd adjust them again, and make sure the nuts are not backing off....if they get worse you could have possibly screwed up the cam. You know, now that I think about it, when I first fired my 235 I didn't do any cam break in either...the engine had been built several years and just sitting....I just primed it and fired it off. Guess I just got lucky....or maybe that is the reason I have the ticking now...?? Good luck...maybe you didn't f** up the cam. It can be replaced with the engine in, but it's still a bitch.....

Brian

[raven]

The new short block had a new cam in it. When I picked up the new short block they gave me a new set of lifters, which I used in the new short block. When I went to prime the new lifters, I noticed that they were solids. when did Chevy go to hydraulic lifters in the 235?
This is a '58 vintage short block.
r

[41ChevyTrucker]

raven61, reading your orig. post are you saying the adjuster nuts are just loosening up or that you have to keep cranking them down a little farther each time to get the same lash setting?

maybe the locknuts are just worn and backing themselves out from the vibration?

[raven]

If I remember right, the first couple of times the lash nuts were actually loosening, the last time they weren't loose at all, just out of adjustment...
r