Engine: "My engine's running rough"

[Mike Van Veghten]

First I'll admit that this post/thread, is sort of useless. The folks that NEED to read it...wont. Why, because it isn't about THEIR, exact...car. BUT...it is !

We all keep reading about all of the cars (NOT..."cars"...but engines !) running rough.
In over 99% of them, the owners report that the ignition timing was "checked (checked to what ?), the carburetor was rebuilt (by whom), the fuel filter was replaced, etc., etc.

BUT in most reports of this kind, almost no one says ANYTHING...about checking the valve adjustment ! In their I-6 or V-8's.
I'd bet that in most cases, even if the valves are/were not the cause of the rough running, that the valves...are...out of proper adjustment.

People, all post war (WWII) Studebakers have mechanical valves from the factory. They need periodic adjustment, especially with no lead in the fuel to lube and cushion the valve to seat contact. The engine will run rough with the valves, out of adjustment, plain and simple. And yes, even with hardened valve seats, just not as often.

Ok...rant done.

Mike

[Studebakercenteroforegon]

I agree. Back before unleaded gas, valve trains all wore somewhat, so a valve adjustment would consist of decreasing excessive clearance. Then, due to reduced valve seat lubrication from the lack of “lead” the valves would recess and thus reduce the required clearance. So typically a valve train adjustment done in the last 30 years or so might find some valves loose and some valves tight. You could always tell the engine was happy again after an adjustment.

[DEEPNHOCK]

Agree here.
Just had a sobering experience myself.
Ran the valves and had a ticking noise at idle when warmed up.
Ran the valves again, but had someone else do the feeler gauge adjustment.
Due to a mobility issue, I did not get 6 and 8 adjusted properly. (No excuse used here...My fault 100%)
Tick noise went away.

[TN GT Hawk]

Agree here.
Just had a sobering experience myself.
Ran the valves and had a ticking noise at idle when warmed up.
Ran the valves again, but had someone else do the feeler gauge adjustment.
Due to a mobility issue, I did not get 6 and 8 adjusted properly. (No excuse used here...My fault 100%)
Tick noise went away.

I'm a bit reluctant to do this because I've only done valve adjustments on air cooled VW engines, not V-8's. But I guess the process is about the same.

BTW, just sent you a reply to a PM you sent a while back RE: manifolds.

[altair]

When I adjusted the valves after an engine job each piston was brought up to TDC and the feeler gage was inserted between the rocker and the top of the valve, if there is clearance and the feeler goes in, any rough running could not be the valve adjustment. Even if it was open too far it still wouldn't matter. If one was too tight there would be a single miss. Rough running would have to be a fuel mixture issue, usually a leaking gasket some where.

[Big Dan]

So, this is a great post! Can I throw another dimension into it that kind of goes along the lines of what 'altair" said?

I just got my Champion running after probably 20 years of sitting in the desert. I ran a compression check, and ONE cylinder was low at about 70psi.

I put a squirt of oil in it and is didn't bring the compression up AT ALL! So, I assumed I had compression leaking past one of the valves (#2 cylinder).

(New head and manifold gaskets, complete water jacket cleaned, rebuilt carb, Pertronix ignition and 92 octane lead free gas)

But here's what is throwing me. I started the engine up and with the exception of a few irregular "spits" when still cold - the thing RAN like a top - no missing NO ADJUSTMENTS. I haven't rechecked the compression since.

Is it possible that low compression check is related to the valve adjustment, and it wouldn't affect the engine as it ran? That doesn't make sense to me.

[altair]

So, this is a great post! Can I throw another dimension into it that kind of goes along the lines of what 'altair" said?

I just got my Champion running after probably 20 years of sitting in the desert. I ran a compression check, and ONE cylinder was low at about 70psi.

I put a squirt of oil in it and is didn't bring the compression up AT ALL! So, I assumed I had compression leaking past one of the valves (#2 cylinder).

(New head and manifold gaskets, complete water jacket cleaned, rebuilt carb, Pertronix ignition and 92 octane lead free gas)

But here's what is throwing me. I started the engine up and with the exception of a few irregular "spits" when still cold - the thing RAN like a top - no missing NO ADJUSTMENTS. I haven't rechecked the compression since.

Is it possible that low compression check is related to the valve adjustment, and it wouldn't affect the engine as it ran? That doesn't make sense to me.

You may have a leaking valve and no adjustment will fix that. Apply some compressed air to that cylinder, if leaking you will hear air escaping back up the carb or out the exhaust.

[Hawklover]

First I'll admit that this post/thread, is sort of useless. The folks that NEED to read it...wont. Why, because it isn't about THEIR, exact...car. BUT...it is !

We all keep reading about all of the cars (NOT..."cars"...but engines !) running rough.
In over 99% of them, the owners report that the ignition timing was "checked (checked to what ?), the carburetor was rebuilt (by whom), the fuel filter was replaced, etc., etc.

BUT in most reports of this kind, almost no one says ANYTHING...about checking the valve adjustment ! In their I-6 or V-8's.
I'd bet that in most cases, even if the valves are/were not the cause of the rough running, that the valves...are...out of proper adjustment.

People, all post war (WWII) Studebakers have mechanical valves from the factory. They need periodic adjustment, especially with no lead in the fuel to lube and cushion the valve to seat contact. The engine will run rough with the valves, out of adjustment, plain and simple. And yes, even with hardened valve seats, just not as often.

Ok...rant done.

Mike

Mike maybe I am a freak, but I have about 30K miles on the R-1 engine that I had rebuilt. That engine has never had the valves adjusted since the re-build. And truthfully she still runs beautiful, basically the same as it did just after the re-build. I will in all honesty say that for now I am still able to mix into the fuel TEL, MMO, and Lubrizol.
I guess when I can no longer afford the mixing of my "witches" brew, then I will have to de-tune the engine.

[StudeRich]

That sounds all good, but IF you were to CHECK the Valve clearances you MAY find the Exhausts getting a bit closer than .024 Hot/.026 Cold or whatever the Cam Grinder recommended.
If you added Hard Exhaust Seats maybe Not.

Running Good, does not always mean all the Clearances, etc. are still perfect.

[Hawklover]

That sounds all good, but IF you were to CHECK the Valve clearances you MAY find the Exhausts getting a bit closer than .024 Hot/.026 Cold or whatever the Cam Grinder recommended.
If you added Hard Exhaust Seats maybe Not.

Running Good, does not always mean all the Clearances, etc. are still perfect.

Yes I have hardened seats and SS valves.

[62 Lark]

After a valve adjustment years ago, I installed this inverse oiler, as an upper cylinder lube. . I run Marvel Mystery oil in it, and it's fully adjustable. The NOS kits pop up on flea bay now and then.