The Stovebolt Site Forums The Shop Area Engine Shop Static valve adjustment for dummies

Thought I would share how I set the valves on my new-built 235 while it was on a stand, using a "companion cylinder" system. First set #1 cyl TDC compression and check with a straw in the spark plug hole. Then mark the damper at 12:00 for reference. Both #1 cyl valves are now closed. So are #s 2 intake, 3 exhaust, 4 intake and 5 exhaust. I set these .010 for intake and .020 for exhaust.
Turn the engine one revolution back to 12:00 on the damper mark and check #6 piston with the straw. Then set both # 6 valves. Next set 5 intake, 4 exhaust, 3 intake and 2 exhaust. Notice in the picture that the column on the left is a mirror image of its companion cylinder in the column on the right. It runs smooth and quiet, cold or hot. I have not had any reason to re-check the valves after 250 miles on the farm and highway. No "ticking." Almost have to hear the exhaust to tell if it's running. Hope this helps someone.

That's the factory service manual method that's been around for 50+ years. It works best on stock engines that don't run a radical camshaft grind. I've probably outlined the actual "companion cylinder" adjustment procedure at least 50 times over the past several years, so the forum archives should have plenty of references to it by doing a search.
Jerry

I guess I should probably do that. That clackety clack is making me deaf.

HRL, Jethro mentioned marking the crank pulley at 12:00. Would it be possible to use that as a TDC mark for a timing light and use a protractor or some other method to make additional timing degree marks so that you could use a timing light at the front of the engine instead of back in that little flywheel hole?

Jerry... I saw references to setting valves this way but it was somewhat confusing to a novice, already somewhat intimidated with the job at hand, counting valves 1 through 12 holding a wrench, screwdriver, feeler gauge and cell phone while reading a message. By charting it out on paper this way, it all came together in a simple, easy to understand format. Thought I would share, not step on any toes. My apologies for not researching the archives before posting.

Jethro, since the procedure is supposed to be done after the engine is warmed up to operating temperature, I assume your engine is running on it's engine stand.

Did you notice any difference in power/response after you finished the adjustment? Did you detect a decrease in noise?

Also, I notice that you used the "Heavy Duty" settings for your valve clearance. Why is that? Is there some benefit to adjusting for heavy duty use even though the truck will not be used in heavy duty service?

The FSM gives a range of .006 - .008" for intake and .013-.015" for exhaust.

What would be the optimal goal in these ranges. Dead center? High side? Low side?

Also, I could not find the companion cylinder method described in the 1948-1952 FSM. In fact, the valve adjustment is described under Minor Service Operations but no procedure is given. It only lists the clearances and tells you to heat up the engine first.

Unless the lash was really loose, there will be no significant change in engine operation.
If even one valve is too tight, that cylinder will stop working.

If you know the diameter of the balancer ring, shop for a timing tape that matches the diameter. Here is a link to Blocklayers, plenty of printable things to play with. https://www.blocklayer.com/timing-tapeeng I use the degree wheel quit often. You will need a stationary pointer and the degree tape, then a timing light would work.

You can also do it at ambient temperature, just set the lash

.004 tighter for cast iron head and block
.006 tighter for cast iron block and aluminum head
.008 - 0012 tighter for aluminum block and head.

Frank

When did the laws of thermodynamics get repealed? Since pushrods and valve stems get LONGER as the engine heats up, I've been ADDING .002" to the cold valve adjustment specs for around 60 years. A hot re-check has always come out just about perfect.

Otto, adding a timing pointer and an accurate mark on the balancer has been done by race engine builders since Ed Iskenderian outlined the "positive stop" method of finding TDC in his book "Top Tuners' Tips" in the early 1950's.

For a ballpark valve adjustment to get an engine up to running temp, get each cylinder to TDC on the compression stroke, gently tighten the valve adjustment screw to eliminate all the clearance, then back the adjuster off 1/4 turn and lock it down. Run the engine up to operating temp and do a final adjustment.
Jerry

My parents didn't even know each other back then.

Jerry, re-read Frank's post. I think he's right. If your goal is .010" when the engine heats up, you'd need to set the gap at .008" (tighter as he said) when it's cold.

To set the adjustment tighter cold and come out right after warmup, the height of the block would have to grow more than the length of the pushrods does. The valve stem would also have to stay the same, and/or shrink. When both the pushrod and the valve stem grows, the clearance gets tighter, not looser, at least in my world.
Jerry

Note: this method works just as well with any L6 engine (regardless of brand, age or size) with the common 1-5-3-6-2-4 firing order.

Note: the stovebolt (and many other L6 OHV and side-valve engines) has its valves positioned as follows (from the front):
Exhaust - Intake - Intake - Exhaust - Exhaust - Intake - Intake - Exhaust - Exhaust - Intake - Intake - Exhaust

The companion cylinder thing works slick. I just work it through the firing order.

I do have to stop and look up the actual lash settings. But the sequence is pretty well engrained in my brain now.

That's why I don't venture from the instructions in the shop manual for anything. The answers to all life's questions are in the manual.

I agree with Otto. RTFM (read the fine manual).

Thus speaks a retired tech writer.

;-) Dean

The rocker arm adjuster’s 7∕16-20 NF thread pitch makes each full turn .050”, .025” per ½-turn, or .0083” per hex flat of rotation.

With the rocker arm ratio factored in, the movement is larger: each full turn is .074”, .037” per ½-turn, or .012” per hex flat , and (if using 12 points nuts) .006” per point of rotation at the valve. Thanks, HRL!

Then the rocker arm ratio needs to be factored in to get the actual clearance change. 1/4 turn back from zero lash works for me for an initial setting.
Jerry

The answers to all life's questions are in the manual

like referring to that thing on the front of the crankshaft as a "balancer"?

Otto... this engine was a fresh build sitting on a homemade wooden rolling stand. New valve job and rebuilt rocker arms. I needed to set the valves close enough for the engine to run when installed without being too tight when warmed up. The last thing I wanted was bent pushrods etc. I chose .010 and .020 as being close enough for the engine to start and run without damage to the valve train. And start it did... ran so smooth and quiet that I decided "if it ain't broke, don't fix it." I've put a couple hundred miles on it and the response has shown plenty of power and zip.. When I hear the valves chattering amongst themselves then I will go in and do an "attitude adjustment." Until then, I will enjoy having to listen for the exhaust to tell if it's running.

Congrats in getting your truck on the road. It’s a great feeling knowing you brought life back to one of these old trucks. Enjoy you rides!

Thanks... except for a few years that on older gentleman had it back in the 70's, it has been on the farm since new. I learned how to drive in this truck 57 years ago. The licence plate dates the pic to 1988. In '89 a new farm plate was issued and that one is still on the truck. Both receipts are still in the glove box. It feels real good climbing back into an old friend and riding again. Real good.

Setting the valves to the heavy duty specs makes sense on a tight, new engine. I'd leave them alone, too.

My valves clatter all the time so I think I need to do this adjustment.

When did the truck go from black to green?

Related note:

There are usually a handful of vintage “valve adjusting tools” on the big auction site. A few years back, I bought an old Snap On version on a whim. I think I paid less that $20.

It’s a total luxury item for as often as I need to adjust valves. A guy definitely doesn’t NEED one. But it sure does make the task much easier.

What sort of tool is it? Special wrench? Go -NoGo gauge?

It was Juniper Green. Between the two photos Halis Parham, the "older gentleman," brushed green metal roof paint inside and out and removed the 235 and put in a 216. I built the 235 to go back in. The paint job will stay... it's part of its history story and it will look better when I scrub it in the spring. "Ol' Halis," the name given it by my buds at the hunt club when I got it back in '86 wears it's battle scars from hard farm work proudly and I'll change none of it.

Mine is like this one (for reference, not my item for sale)

https://www.ebay.com/itm/2660078288...r=&widget_ver=artemis&media=COPY

But there are a few different makes and styles. On this one, you just add your own 5/8 socket to it.

Edit: Upon further review, my tool is the “V22” model. But you get the point.

Those tools kept the feeler gauge manufacturers in business- - - - -the best way in the world to destroy a feeler gauge was to try to do a running adjustment on an engine with worn rocker arm tips! The "third hand" tools made it possible to really mangle a feeler gauge blade in a hurry.
Jerry

LOL. I have never tried, nor felt compelled, to adjust valves on a running engine.

Benny Hill theme music starts playing in my head, when I try to even imagine doing it that way.

I tried it once on my hydraulic lifters. Did it all the time on SBC’s, but the adjuster was on the pivot, so it didn’t move. Trying to keep a flat bladed screwdriver on the adjuster and a box wrench on the locking nut was impossible for me. Heat the engine up to running temperature, then shut it down to make your adjustment.

I grew up around a bunch of oldtime wrench jockeys who insisted the only way to get a good valve adjustment was on a running engine. They would turn the idle speed WAY down and chase those rocker arms with a screwdriver and a box end wrench, and it was amusing to watch. As I mentioned before, if the rocker tip had a divot worn into it, any kind of adjustment method except a dial indicator was pretty useless. There was a dial indicator equipped tool called a "P & G Valve Gapper" that was clipped onto the top of the valve spring and monitored the movement of the rocker arm that was supposed to be able to compensate for a worn rocker tip, but they were very expensive, and pretty fragile.
Jerry

Ya, when I get around to making the adjustments, it'll be on a non-running engine for sure.

How would they have set them in the factory? I imagine that they set them cold. Probably zero lash, back out a bit, set the lock nut and on to the next station...

Anybody know? And if the factory can set them cold, why do you need a hot engine the next time?

Very few people know what valve lash actually is, and why there's a specification for setting it. Everybody's got their own pet method, and writing a novel the size of War and Peace isn't going to change anyone's mind. Not all cams, even for the same engine from different manufacturers, will have the same adjustment specs. There's a very simple, totally accurate way of figuring out what the lash adjustment for a specific cam should be, but getting anyone to actually check it is as likely as finding a chicken with lips!
Jerry

I guess the block, the head and the rocker stands expand much more than the pushrods, valves and lifters,

But don't take my word for it: cold lash setting


I did that once - it was scary.

What really bummed me is how much the rpm drops/rises when you tighten/loosen the bolts on the rocker arm stands.

Frank

Locking this thread. The OP was only telling us about his success. Time to move on.