Looking for some Help...SBC Oil fouling plug

[Horder]

Schurkey was correct. I did the test wrong.

The carb cleaner was being pulled into the carb making a rich condition and stalling.

No action when the vent tube was removed.

Back to the drawing board...

I think I will pull the springs on #1, feel the guides, re-seal the rocker studs, and put on two new seals.

Thoughts?

[Tom68]

I'm running a sj 327.
No guide seals, just the square orings on the stems, I get a little oil ash on the plugs, but I did build it back in 1983.
Maybe your seals have been pulled up by the dampers.

Grease would be enough to seal the rocker studs unless the machining cut along the top is heavily grooved.

[Schurkey]

He added a massive amount of air, it would then be lean but still has to pick up speed.

If the mixture was "right" with the PCV system in place, adding a massive air leak--an uncorked 3/8 hose--would lean the mixture to the point of stalling the engine.

[Schurkey]

I think I will pull the springs on #1, feel the guides, re-seal the rocker studs, and put on two new seals.

Yes, sir.

As suggested, the finest thread sealer I've used is Loctite/Permatex "PST" which comes in several varieties. #592 is the easiest to source--most any auto parts store has it. Not only is it "Teflon" (PTFE) but it has an anaerobic hardener in it, too. Like a mild thread-locker. Fabulous stuff on either pipe-thread or bolt thread.

https://www.amazon.com/dp/B0002KKTH2/?c ... _lig_dp_it



There's other part numbers--565, 567, and a chapstick-like semi-solid #504467

[HQM383]

Picture of said plugs?

Oil coming down from the top will mist (atomize) a bit through being caught in intake air and burn different than oil coming up from the bottom.

[Horder]

I will put in a fresh plug and run it, and post pics...

Again guys....thanks for the help

[Tom68]

He added a massive amount of air, it would then be lean but still has to pick up speed.

If the mixture was "right" with the PCV system in place, adding a massive air leak--an uncorked 3/8 hose--would lean the mixture to the point of stalling the engine.

Of course I was forgetting that's exactly how the oem's solved dieseling with carbs, open a vacuum solenoid when ign was switched off.

[dannobee]

I'd go back to the bore scope tool (ie "Inspection camera") and look down the intake ports. The trail of oil should be fairly easy to locate, if not obvious. Look at the intake gasket, the valve stem, and the rocker stud. And you have 7 other intake tracts to compare it to. If you don't find anything, look in the cylinder through the spark plug hole.

For some unknown reason, every woman that has seen my borescope tool wants to borrow it. Go figure.

[Horder]

Here is a pic of a plug after 1 hour run time. I marked the plug with red ink on the top side after installation. I then put some black ink on the threads after it was pulled to show the top.

Top side and bottom. Bottom is much more tan.

[steve cowan]

Plugs look nasty,
Regardless of whether it's PCV,sucking oil from base of intake manifold, or Napier second ring upside down my opinion is I would pull engine as it probably has glazed the bore on that oily cylinder. If you are determined to use the stock PCV system I would incorporate a air/oil separator in the system.

[Horder]

Well....not what I was hoping to hear. I had hopes it might be a top end issue.

I redid compression testing on all cylinders today. Got 174-181 on all 8 with #1 being 179 PSI

I picked up some seals today but won’t get a chance to work on anything for a while now as I’m starting vacation.

I have a borescope on order

[Tom68]

Well....not what I was hoping to hear. I had hopes it might be a top end issue.

I redid compression testing on all cylinders today. Got 174-181 on all 8 with #1 being 179 PSI

I picked up some seals today but won’t get a chance to work on anything for a while now as I’m starting vacation.

I have a borescope on order

Don't take equal cranking pressure as a burning oil diagnosis, it only proves the compression ring is sealing, probably with a good oil coating in #1 helping that seal.

Let's hope its a dislodged or torn intake guide seal.

Were the rocker stud holes counter sunk enough to clear the radius on the stud ?

[Horder]

I changed oil after the first hour of running.

I’ve put a few tanks of gas through it since then. I’ve been keeping a close eye on the dipstick and to be honest I haven’t seen much change if any???

[Tom68]

Casting flaw in the valve spring pocket I guess is another possibility.

Not a Chev head but fuellies were close even with their smaller pockets.

02-acp-cylinder-head-theory.jpg

[steve cowan]

I have a set of these trickflow heads that I done work on.
The guides need to be honed to size as they do mention when you read the paperwork. They are a nice casting.
I always seal around the intake ports with silicone on a low port head as well.
It does not take much for a angle miss- alignment.