The Stovebolt Site Forums The Shop Area Engine Shop Valve Settings!!!!!!!!!!

Is there cold settings on the valves for a 1942 Chevy 235 engine that will work so I don't have to try to adjust them hot? Thanks!!!!

Marv.

Only as a preliminary adjustment when work has been done that would change the settings. The fnal adjustment must be made with the engine warm.

I was hoping that someone with knowledge of metal heat treating would know what the expansion of the valve stems would be at operating temperature. Is this possible??????? Thanks again!!!!

marvin ribbich,

If you ADD .005 to your hot specs when you set your valves COLD, you will be very close.

It would be good insurance to check them when the engine was up to temperature, but not necessarily running. With the valve cover off and the plugs pulled, this isn't a big chore. I think Hotrod Lincolns 'companion cylinder' method makes this task even easier.

I personally like to set the valves hot with the engine running. I find it quite accurate, and not as messy as folks make it out to be...these old rockers 'drip', they don't spray!

Stuart

I'm with atomarc on this one. No big deal to set them with the engine running. That's the way my uncle did them (GM mechanic).

Isnt setting valves on solid lifters with the engine running asking for trouble???

rustednuts,

You might be thinking of hydraulic lifters, although they can be set perfectly fine while the engine is running too.

Solid lifters are traditionally set with the engine warmed up and idling. Take a look at the Chevrolet service manual for an AD 235 engine.

Stuart

No, I was thinking solid lifters since you have no play in the lifter.

Hydraulic if done slowly will keep squishing the oil out of the lifter without bending pushrods.

I thought my manual says warmed up with the engine off.

I dont remember drinking to much egg nog... What am I missing?

Chasing a moving rocker arm around with a screwdriver, a feeler gauge, and a box-end wrench is an exercise in frustration, plus it's messy. Go ahead and do it that way if you choose, just to be traditional, but it's pretty difficult to get a good adjustment. The difficulty usually crops up when the tip of the rocker arm gets worn concave, or the acceleration ramp on the cam wears out, and no matter how close you think you're getting with the clearance, the valves still rattle. Attempting a running adjustment on a hydraulic lifter is just foolish!
Jerry

I have adjusted hydraulic lifters many times while the engine was running. What didn't I understand about this that made my task 'foolish'...in your opinion.

Stuart

Another way to check the tappet clearances is set them slightly loose cold, run the engine for about 20 minutes after the heat indicator on dash shows normal running temperature. Valve tappet clearance should be adjusted with the aid of a vacuum gauge. With warm engine idling saturate valve stem and guides with penetrating oil. Watch vacuum gauge while inserting a 0.002" feeler stock between stem and rocker arm noting the vacuum reading. If the 0.002 " feeler causes the needle to fluctuate, increase clearance until needle is steady. If no change in reading tighten clearance. Repeat till all are the same.

Every fraction of a second, the cam lobe comes around and slaps the valve open, which means that it's impossible to get a true "zero lash" starting point on a running engine. The lifter is going to be operating in a partially-compressed situation all the time, plus it's going to be virtually impossible to get a true adjustment with the lifter moving. Compressing the lifter while it's stopped on the base circle of the cam lobe, and measuring the exact amount of bleed-down between the lifter body and the plunger is the only accurate way to get an adjustment, but a stopped-engine adjustment without waiting for the lifter to bleed down is usually suitable for street use. I'm accustomed to adjusting race engine hydraulic lifters that operate in the 7,000+ RPM range, and a running adjustment is definitely out of the question in that case.
Jerry

I have only adjusted valve settings on truck engines - all 216/235/261 truck engines had mechanical (solid) lifters. Years ago, I adjusted valves with the engine running (after warming up the engine). About 10 years ago, I started using this technique on a warmed-up non-running engine. This is a lot easier, less messy, and seems to give excellent results.

As stated above, if the engine has been rebuilt, or the rocker arms removed, and/or the rocker-to-valve-stem surface has been ground/polished, you can set the cold clearance about .005" wider to start and warm up the engine. Then, the valve lash can be set on a non-running engine.

I can't open your link tc but I do know how to static adjust the valves. I still prefer the running engine technique. As far as chasing a moving rocker with a screwdriver, wrench, and feeler guage: I have a tool with the screwdriver attached over the box end that you can operate very easily with one hand. I used to see these in any parts house (they may still have them).

On my hydraulic lifter 235 I just back each lifter down until it clatters, then tighten until it just quiets down. Is this not a good procedure??

Couldn't you simply adjust the valves with the engine at operating temperature, wait for it to cool and then check the setting to determine what they should be set at when cold?

Also, what about using a dial indicator? I remember many years ago that if the rocker arm is concave a feeler gauge isn't accurate.

Again, forgive me if my thinking is all wrong, I'm not a mechanic.

Take a hydraulic lifter apart sometime, and look at the relationship between the pieces. Yes, there's a little fudge factor to allow for adjustment errors, but they don't work right unless a pretty narrow adjustment window is achieved. Chevy is about the only engine out there that allows for hydraulic lifter adjustment. Most of the others depend on specific-length pushrods and/or grinding of valve stems to the correct length on a valve job. I'm getting a little tired of arguing with people who weren't even born when I started adjusting lifters, solid of hydraulic! It's a waste of time!
Jerry

Yeah clue me in on the hydrolic lifters too! I'v always done em running.Tom

Jerry,

I checked the personal profile of everyone that posted on this subject and can find no year of birth for any of them.

My birth date is July of '46...were you adjusting lifters previous to this?

Stuart

You guys blow me away...tclederman(much repect for your trucks brother!) gave a pretty good answer, but No one gave the man the specs he asked for! The correct answer is .006 Intake and .013 Exhaust HOT! If you wanna try it cold, go about .008 and .016. If any of you have hydraulic lifters, the correct setting is Zero plus one and a half turns, WITH THE ENGINE RUNNING! For anyone who cares, all the motor oil on the shelf has had the zinc removed! Please use Valvoline VR1 Racing Oil, Rotella T, or Royal Purple only in your cast iron blocks! Otherwise, you are looking at new bearings, cam, lifters, and oil pump very soon!

.006 and .013 is corect for passenger, truck (or at least stock '55) is .006 and .018 for 235. i set mine hot, engine off, like HRL does. It can be done running, but can be a pain unless you get the rpm very low or have the special tool for doing it.
Not to hijack the thread, but have you come up with a definite answer on Royal Purple, AZRacer? I've been trying to come up with a definite answer if it's ok for flat tappets, but noone seems to be able, or want to, give an answer on synthetics. Right now, I'm running Valvoline 30wt Super HPO, and according to the Valvoline site, they haven't reduced the zddp in their oils. I have been considering going to RP or possibly Lucas (I've used their products with exellent results), but want to be sure before I make the switch.

At the link I gave above are mechanical valve lash settings (hot) from various Shop Manuals and Owners Manuals (they do not always agree, even in the same year):

216 cubic inch
Intake: .006 to 008; .010 for heavy duty operation
Exhaust: .013 to .015; .010 for heavy duty operation

235 cubic inch (high pressure)
Intake: .006
Exhaust: .016 or .018

261 cubic inch
Intake: .006
Exhaust: .018 (up to 1 ton trucks); .020 for 1 ton and larger trucks

I'm used to setting valve clearances on SOHC and DOHC engines. I wouldn't be caught dead trying to adjust one with it running, so I do the stovebolt with it off as well.

Ok automark-dob,1957 youve been at it longer than me!!

I don't mean to be argumentative but this information contradicts the factory specs according to THE MANUAL.

Can you please verify your setting for the intake lash and qualify your reference, or point out the error in my thinking?

Woody,

There is no problem in pointing out what could be a mistake. It's been a few years since I accumulated that information and I am out of town until late Sunday. I'll look up the numbers in several manuals and post them late Sunday. The high pressure 235/261 numbers most likely came from a 1954 manual.

As stated above, the settings came from, "various Shop Manuals and Owners Manuals (they do not always agree, even in the same year)".

That 1955 Shop Manual that you linked shows a setting of .020 for the intake valves. That seems very wide. Take a look at the same year's Owner's Manual: .006" for intake (and .016" for exhaust).

Tim

Hey AZRACER,

I have hydraulic lifters.

You say, "the correct setting is Zero plus one and a half turns, WITH THE ENGINE RUNNING!"

How do I determine/find Zero lash, while the engine is running?

Hydraulic lifters are a foreign realm to me, but you might be interested in the procedures/recommendations at the bottom of this tech tip: http://speedprint.com/deves50/valveadjust.php

Now, you hydraulically lifted stovebolters have a few new things to opine over.

Tim

Oilrag to adjust hydraulics usually you back off the nut until you can start to hear the rocker and pushrod tapping away. Slowly tighten until the noise subsides and that gives you your zero setting. Now SLOWLY turn about 1/4 turn at a time until your at your adjustment. I dont know what the setting is for these so I cant tell you if it is 1 1/2 turns??? I know a SBC is about 1/2 - 1 turn depending on who you ask.

I was never answered before, but isnt setting valves on solid lifters with the engine running asking for trouble???

Thanks, Jeff

Jeff,

I did make a comment on this. It's common and done all the time.

If you're in a shop building "race engines", you have the engine on a stand, no car, and no way to install and run the engine. These would be the conditions where one would set the valve lash with a non-running procedure.

If you are in a working automotive shop where the customer is paying $75 dollars a hour and he drives the car into the stall, you would adjust them with the engine running.

If you adjust them running on a regular basis, handling the stubby screwdriver, end wrench and feeler gauge would become habit. It's difficult to be proficient at something when you never do it, but that doesn't mean you need to brand the gentleman that does it the "other" way a fool or a shade-tree mechanic.

Stuart

Well, I guess I'm one of them "hydraulically lifted stovebolters" and I don't feel so bad after reading the article tc linked to. The author suggests adjusting hydraulics in 2 stages, first with engine off, then, I guess to make sure everything's kosher, with engine running. I just have always skipped step 1 and went right to step 2.

I didn't add hydraulics to my '54 "Y" code block, it came with them from the factory so, after 50 plus years of operation, I'm not too concerned that the 235 engine won't supply enough oil pressure to keep the lifters pumped up.

And, it seems to me that either running or non-running techniques work equally well with solids. I've done it both ways and have never burned a valve or bent a pushrod.

I'm ready to bury the feeler guages and just try to get along.

Finding zero lash on a running 235 engine, with hydraulic lifters, will not be accurate.
It will only be a guess.

As far as I know, the only way to determine you have zero lash, is on an engine that is not running.

With one hand on the pushrod and a screw driver in the other hand,
turn the rocker arm adjusting screw until all clearance
between the valve stem and rocker arm is removed.

You must find zero lash before you continue to the next step.

If there is another way to find zero, please let us know.

Stuart, Im sorry, I didnt realize I had 'branded' anyone a fool.

I asked a simple question and apparently missed the response. Ive never done it myself (running w/solids) and I never said it was wrong. I was under the impression doing it with solid lifters would mean your chances were far more likely to bend pushrods or worse.

There are always exceptions to every rule. I adjust hydraulics with the engine running, just wasnt sure about solids???

Im a little confused, did I miss something???

Jeff

Jeff,

That comment wasn't directed at you, sorry for the inference. You asked a perfectly legitimate question and I guess I muddied it up with my rant....sorry!

Stuart