Engine: Running out of Valve adjustment

[Steve Winzar]

Hi all-
I am close to running out of valve adjustment on the Reconditioned 289 V8 I'm building. Of note is that the oil holes at the top of the rocker arms in the Left bank are almost shut by the adjusting screws, the right bank are well and truly shut. I believe that a couple are at their maximum and will not allow a 0.027 cold valve adjustment .
Now, I believe I've done my homework right-
1961 engine with number P77537 (therefore, after modified rockers and pushrod sets occurred)
All rockers show part No. 1550613- later production as per above
All Pushrods in my collection were all the same length- give or take a 'poof-teenth' - in the order of 11 5/16" long
All adjusters look to be barely one inch long= i.e. short versions as required for 15450613.
I have installed 0.015" steel shim head gaskets rather than the wafer type the heads originally had out of the '63 cruiser.
The block has been decked a minimal amount- I believe that it has never been shaved before.
The heads came off another engine-a '63 cruiser. I believe that just maybe they might have been shaved before- checked volume of one combustion chamber at approx 65cc. I imagine this might be the mail cause.
I'm wondering what more experienced fellers might suggest-
Do I pull the rockers (damn- just pulled down both head gaskets!) and shorten the adjuster screws to expedite oiling?
Ought I shim under the rocker stands to lift 'em up?
Do both the above.
Cherry picking the shortest pushrods out of my spares collection to re-install is a commonsense option but not likely to solve the problem on its own.
Steve

[doofus]

Steve you have come up with a head scratcher!!! the valves are probably sunk in to their seats. I am a CASO so i would shorten the adjusting screws first then go through all my spare push rods. let us know how things come out. Good Luck , Doofus

[Bud]

I've seen your problem in the past. It's a combination of the deck and block being milled, valve seats being cut a couple of times and valves being refaced causing the valve stem installed height being incorrect. Add to this the use of a shim head gasket and you run out adjustment on the rocker arms. I don't know that the adjustment screws can be shortened as the adjustment screws are installed from the bottom of the rocker arms and have the socket for the push rod in them. Using shorter push rods is the easy way to solve your problem without tearing the engine apart. Bud

[bezhawk]

It must have been an export Cruiser, as those are low compression heads. Same as trucks, and the R2 engines. Someone may have put GM valves in as a replacement, they are much shorter.

[Hawkowner]

Had this problem with a 53 Cad that had the heads milled but non adjustable rocker arms because engine had hyd lifters.
We shimmed the rocker shaft stands and cured the problem it was a simple fix that worked.Another solution would be to grind off the top of the valve stems like setting the clearance on a flat head Ford but you would have to pull heads and replace head gaskets.
l am making the assumption that the adjusting screws are going too deep into rocker arms.

[PackardV8]

IIRC, the '51-61 pushrods are enough shorter to solve your problem. Try finding one of those, install and see if that gives you more room to back out the adjuster. You won't bother the head gasket removing the rockers, but it's possible to replace pushrods by moving the rocker to the side as each valve is closed.

jack vines

[altair]

If the lifters were reground to the standard convex may have offered additional adjustment. As suggested above find shorter push rods.

[Dwain G.]

Earlier pushrods measure 11 11/64" to 11 7/32". Late pushrods, 11 21/64" to 11 3/8".
I don't have the spec for valve installed height, Jack V. probably does.

[PackardV8]

Earlier pushrods measure 11 11/64" to 11 7/32". Late pushrods, 11 21/64" to 11 3/8".
I don't have the spec for valve installed height, Jack V. probably does.

Installed height 2.032"

jack vines

[Steve Winzar]

Steve you have come up with a head scratcher!!! the valves are probably sunk in to their seats. I am a CASO so i would shorten the adjusting screws first then go through all my spare push rods. let us know how things come out. Good Luck , Doofus

Thanks for the reply, Doofus. I had not thought of valve seat recession and that may well be a conributing factor.
Yep, headscratcher....trust me to do that !
By the way what is CASO??
Regards, Steve

[Steve Winzar]

It must have been an export Cruiser, as those are low compression heads. Same as trucks, and the R2 engines. Someone may have put GM valves in as a replacement, they are much shorter.

Thanks Bez- you are correct, this is an Australian Stude, likely CKD and assembled here. I made a real mistake by not reconditioning the original higher compression heads. I had a little corrosion pitting in a couple of combustion chambers and decided to pass on them since I had a few sets of heads spare. Back in the day (I was only six or seven years old then!) we had 'Standard' grade petrol, so the Studebakers would be able to use it. I believe the valves are indeed OEM Studebaker.
Steve

[Steve Winzar]

I've seen your problem in the past. It's a combination of the deck and block being milled, valve seats being cut a couple of times and valves being refaced causing the valve stem installed height being incorrect. Add to this the use of a shim head gasket and you run out adjustment on the rocker arms. I don't know that the adjustment screws can be shortened as the adjustment screws are installed from the bottom of the rocker arms and have the socket for the push rod in them. Using shorter push rods is the easy way to solve your problem without tearing the engine apart. Bud

Hi Bud-
I was thinking of removing the adjusting screws and grinding the ends of the threads to expedite the opening up of the oil hole up at the top of the rocker arm. It appears I'm on the right track from what you have said. My preference at this stage is to make up some shims and bunk up the rocker shafts just short of 1/16" rather than grind any adjusters- I hate buggering up original parts. I daresay that as time goes on , Stude enthusiasts will see this problem occuring more commonly.
Steve

[Steve Winzar]

Had this problem with a 53 Cad that had the heads milled but non adjustable rocker arms because engine had hyd lifters.
We shimmed the rocker shaft stands and cured the problem it was a simple fix that worked.Another solution would be to grind off the top of the valve stems like setting the clearance on a flat head Ford but you would have to pull heads and replace head gaskets.
l am making the assumption that the adjusting screws are going too deep into rocker arms.

Hi Hawkowner-
You are correct about the adjusting screws- they are getting screwed right up inside the rocker arms. a couple are at their limits and proper clearance can't be achieved. Thanks for confirming the idea about shimming as I am going to go down this track in preference to any other adjustment means.
Steve

[Steve Winzar]

Thanks Dwain- It is evident that all my stock of pushrods are of the longer type. Thanks for confirming those lengths- I have a copy of a post from some time ago and I think they were wrongly quoted in that.
Steve

[Steve Winzar]

Installed height 2.032"

jack vines

Hi Jack- Thanks for that. As best I can measure with a rule it looks like I have just under 2 1/16"- but I am measuring from the top of the rim around the spring pad and I'd guess that isn't the right place. That would mean the installed height is plenty higher than specified- am I right?. I notice that the reconditioners placed copper spacers under the springs, too.
Regards, Steve
Steve