[Goatracer1]

I have a rebuilt 1962 389. (I did not have it rebuilt) It ran great. Used no oil. But it pinged badly even with 93 octane gas. Over the winter I changed the heads and intake to 1969 #62 heads and 1965 intake. I used the heads that I removed from my race car 20+ years ago. They had been wrapped in plastic and stored in the house. I lapped the valves and replaced the Perfect Circle style seals with NOS seals that I had in stock. They seemed fine. The problem is that after about 200 miles the engine has started smoking. Were my seals just too old or have I over looked something?

[Goatracer1]

Does anyone have a part number for aftermarket seals to fit the #62 heads if they are the problem?

[pfilean]

Before I got my 61 the PO had the engine rebuilt. Bored, polished crank valve jod new Comp cam. Ran nice but used about a quart every 500 or so. Not good. The rebuilder (experienced Chevy dirt track builder) Put in new valve springs as recommended by Comp. But the springs were a little larger diameter than the stock springs so the drip caps had to go. Should have put on the umbrella seals but only put on the little seal in the spring retainers. I bought another set of heads and had a valve job done using the stock springs with the drip caps and the little seal in the spring retainer.. No umbrella seals. Did a quick head swap and the oil usage is near nonexistant. Sure, I don't put on a lot of miles and change oil based more on months not miles but i don't add between changes.

Without the Perfect seals do you have the drip caps?

[Goatracer1]

It has PC style seals. I don't know what you mean by "drip caps".

[Sirrotica]

I'd be looking at the ring seal, if the engine was pinging/detonating previously. It's not hard at all to break an upper ring with detonation. I've done it on a couple high compression Pontiacs in the mid, and late 70s when all we had to choose from for fuel was 87 unleaded, or 89 leaded fuels.

Compression check or/and a leak down check should either confirm whether you have a broken ring, or damaged ring lands on the piston.

Looking at blowby with the breather/oil fill cap removed sometimes will show a variance if only one cylinder is affected, a puff while looking at the vapor usually signifies one cylinder is leaking more than the others.

[Sirrotica]

Originally Posted by Goatracer1

It has PC style seals. I don't know what you mean by "drip caps".

I believe he's talking about the stamped steel umbrellas/shields that fit between the retainer and valve spring. That would be what you'd leave out if the valve spring was larger diameter than stock springs.

[Goatracer1]

Engine ran great before and after heads were changed. Idles dead smooth and no blow by. Blows smoke for short time after idling. Don't know about when driving down the road. Can't see any and haven't been able to have anyone follow me.

[77 TRASHCAN]

I know I’m preach’n go to choir, here. Have you tried disconnecting the PCV valve?

[pfilean]

I believe he's talking about the stamped steel umbrellas/shields that fit between the retainer and valve spring. That would be what you'd leave out if the valve spring was larger diameter than stock springs.

Well said Sirrotica. I don't remember what they were called but that was the item. They did help. Of course the PC seals are better.

[25stevem]

There are two common size Viton type valve seals depending on the size that the tops of the valve guides are.
If your guide tops are the more common .530” OD then comp cams 518-16 are the seals you need, if the guides are .500” then the part number is 517-16.

If you want the O-rings for use in the bottom of the stock retainers, that is 501-16.

You should also get the proper installation tool for the seals that go on the valve guide, or if you can tack weld you can make one from a cheap tall socket and a washer.

Do not use Teflon valve seals on the exh valves of a street or street strip motor as they seem to run the exh valves too dry.

[Goatracer1]

Thanks for the part numbers. Now if they aren't on back order I'll get some.

[25stevem]

There are other brands that are the same deal if that happens, it’s just that the outer case may be metal, but it makes no difference in there function.

[25stevem]

You did not mention how much valve lift you are running with this 389/ 62 head combo, but if your running stock retainers and have positive valve seals on the guides there may be a issue.
I have to get home to check my notes, but at about .470” lift ( with a stock valve installed height ) you may be pounding the bottom of the stock retainer into the top of the guide seals.

It may take only 200 miles of this to do in the valve seals and make for your condition.

[Goatracer1]

Thanks for the info about the retainer. I don't know what cam it has but when I installed the heads I tried to measure the lift and it seems to indicate a stock replacement cam. When I pull the springs off I'll check for damage from the retainers.

[Tim Corcoran]

Sounds like valve seals to me I would install new valve seals and make sure your retainer is not hitting the valve seal.

[Willshire]

Subscribed. I'm looking at doing a 389 (.030 over) with 068 cam and 62 heads. Any detonation issues with the 72cc 62's?

[Goatracer1]

See my answer to your post about heads. Hope that helped.

[geeteeohguy]

We need to diagnose the engine, guys. Is it valve seals or rings? Valve seals IF: it smokes on decel, like coasting down a hill. Or puffs smoke on start-up after sitting. High vacuum situations.

Rings: if it smokes on accel or under load or being revved up. Low intake vacuum situations. A leak-down test will verify ring seal is good.

Valve seals and rings are two entirely different animals with entirely different solutions. It's a total waste of time to try to blindly trouble shoot this engine with insufficient information, IMO.