Read this first part of this thread: http://forums.corvetteforum.com/show...05&forum_id=48

Yestrday I removed two rockers and springs in order to see the oil seals on the valve guide. I was expecting worn or missing or fluctuating seals. NOTING the seals are perfect planted on the valve guide. And there is no play between the valve stem and the guide. .
The seals seems new too.
how can i collect a teaspoon of oil at the back of the Intake valve when this is closed. I'm missing something? The only way the oil can stay there it's thru the valve guide.... I'm wrong? some other test to try?
Thanks
-Beppe-

 

Did not go to the other thread, so I might be missing something.....but do you have rocker studs that go into the intake port? If so the oil could be following the threads and making it into the runner.

Also you need to disassemble the heads to really check out the valves and the seals.

I just had my springs changed on my 2year old heads ~4k miles on them max, and the valves were worn severely??? Brodix uses junk stuff on their assembled heads and my intake valve stems were .008-.010" worn!

If the heads are off the car, I would have them taken apart and at a min new valve seals put in, yours could be dried/worn. Is it EVERY port that is getting oil? How do you know its coming from their? Reversion can deposit oil in the runners as well if your rings are not good. So can an intake leak.....

 

Yes, studs goes in to the ports on my Trickflow heads.
I'm sure there is rtv on the treads.
Remove the heads?? There is NO play in the valveguides...
The seals (positive Viton) SEEMS like new.
I don't think it's my case.
It SEEMS that every ports has oil sitting on the int valve. (some more...like a teaspoon others just coated with something that seems oil).
I don't understand the Reversion thing...
Ok, during the overlap I can have some gasses returning up to the runners. But ...How can collet oil on the intake valve if the culprit are the rings? If the rings are worn (Leakdown test is GOOD..) the oil should be sucked in the combustion chamber and BURNED BEFORE to entering in to the intake tract and be collected o top of the valve..
I'm wrong? I'm using a 219 cam not a cam with a diabolical OVERLAP..
?

Thanks
-Beppe-

 

If every intake valve had oil on the head this appears that the oil is being introduced through the intake manifold instead of the valve seals. Did you check your PCV valve to see if it is good and that oil is not being drawn through it? Look inside the PCV valve hose to see if there is oil in there.

 

I believe he said he has no PCV-sounds like bad guides to me-

 

Let's try to analyze this logically. It can't be rings. The ports have no oil, so it can't be oil sucked from the valley. The oil cannot be puddling on the backs of the intake valves while the engine is running. There may be oil passing through there when the engine is running, but the rings stop pumping and the manifold stops sucking, when the engine is shut off, which is when the oil is accumulating. That pretty much narrows it down to two sources; the rocker studs or the valve guides. How are you holding the valves from dropping into the cylinder while you are removing the spring? Air pressure? Are you releasing whatever is holding the valves in place, and allowing them to drop a 1/4" to 1/2" to effectively check the guides for wear? The first thing *I* would do is remove each intake rocker stud, inspect it for oil, clean the threads that go into the head and reinstall them with Permatex No. 2, or some other good, non-hardening gasket sealer. You could try replacing the valve stem seals at the same time. If you find oil on the threads you can button it up and give it another try. To fix the guides, the heads will have to come off. In my mind, the only way for oil to accumulate behind the valves, is with the engine off. And to me the only way oil can get there is by gravity. Let me know if you see a flaw in my reasoning.

RACE ON!!!

 

Can't get any better than that CFI-EFI. Since it sounds like this is happening throughout the entire train, and actually a teaspoon of oil is
a considerable amount-I would almost eliminate seals, very well could be the studs-but still that's a substantial amount of oil-which leads me to believe there was a poor job done on the guides. Just my 2 cents.

 

Guides or studs, but that is a lot of oil.

 

It is a hellava lot of oil. I wonder if Beppe has an oil drain back problem out of the heads?

RACE ON!!!

 

Maybe-but I doubt it-what is there, a half inch drain hole, front and back on both heads? I think someone did a **** poor job on the guides.
Seals-maybe, but that's unlikely to account for that much oil on the valves-

 

No, PCV is not the source.
Yes, the CFI EFI reasoning is what I allways thought.
But the two seals I removed seems right new, not distorted , not brittle. Yes, I tried the clearance of the valve stem at every valve lift an there is NO play. I also put a hand vacuum pump on the guide with the valve open and I can maintain vacuum.
I have not yet removed the studs, but I can see that there is RTV on it.
Probably the RTV is not good? I have to use a Teflon pipe sealant?
but even thinking that the RTV is not the proper sealant to use, it is possible that using RTV it's worse than using nothing?. I also thought to remove the heads...but on my little garage it's very difficult to remove all others parts involved. In addition I think it's very difficult to add the correct torque on each bolt of the head with the engine in the car.
-Beppe-

 

Just a thought, did you remove the shield on underside of super ram base and checked to see if all the pipe plugs are in and have sealant on the threads

 

What I can add is that not all rtv's are very oil resistant. The ultras (blue, black, copper) are the best in the series and "right stuff" is far superior for stength and oil resistance. Ultras would work, with extreme prep (zero oil, crud,etc.) I wouldn't use the right stuff on r.studs. With any of these, there is the potentail for some silicon can get into the oil etc. Also if rtv's were to be used it would be important to let it cure all the way before use.
Permatex #2 is an excellent product for the studs. Prep is very imp. clean all thread thouroghlly, on bolts after all the crud is off I use some carb cleaner. The only thing about yours is I always 'chase' the thread w/a tap to get all the crap off the threads. On yours the old selant etc.will fall in, and I'm not sure you can if you can get a rag deep enough in there to prevent that (don't own that style head, mine don't go all the way through).

As to torquing and or removing the heads, the biggest PIA doing it in the car is re torquing the bottom head bolt #8 cylinder (pass. side).

 

The intake WAS installed WITHOUT the shield. OK, this is not good for the heat that the manifold receive from the hot oil in the lifter valley... but if the plugs are good sealed there is non way the oil can be suked in.
I've NOT checked if the plugs are full screwed or with sealant because I haven't found yet an allen wrench so big to use with...
-Beppe-

 

I can't find the permatex #2 here in Italy..
I have a Mr. Gaskets product called Pro-Pipe teflon sealer non ardening compound... (I don't remmber if this is the right name ....but it's very similar...)
This is good for the studs?.
-Beppe-

 

I have never used liquid teflons in this area, so I would not want to lead you down the wrong road. If I only had the choice between the teflon and say ultra black or blue, I would go with the Ultra.
What I can tell you is Permatex #2 ('form a gasket'), is a reisin based formula not a teflon or silicon, according to permatex. Permatex has a # that might be able to provide you information on availabilty internationally 877-376-2839.
Sorry, I always forget where you live and what you must have to go through to get some things we take for granted.

 

Whatever you use, make sure it is O2 friendly.

RACE ON!!!

 

Is this the permatex #2?

 

Yes. See the part number on the tube? The "A" designates the size of the tube. Some where on the tube it will say, "Non hardening".

RACE ON!!!

 

Probably I find the source of the oil on the inlet valves even if I'm a bit skeptic on this.
The source can be the studs entering in the intake ports.
Putting a finger on these holes, the finger has a little of oil on it.
I tried to put a lot of oil on the stud from the TOP of the head, but there is no vacuum to allow the passage from the rocker area to the head port. I have a manual vacuum pump, but it's impossible to put the tube of the pump (or an adaptor) on the hole in the port of the head. Probably applying the vacuum directly on the port of the head will be a good test to see if the oil surrounding the stud can migrate in the port, but it's very difficult....I haven't an adapter of the shape of the port.
I'm open to suggestions to find a way to apply vacuum on the port.
-Beppe-
PS could I use teflon tape on the studs instead of the permatex 2?