Might this be intake reversion?

[440beep]

I'm in the process of freshening my 440+ RB block and we came across this black crud on the pistons and intake valve. My builder is thinking this might be from reversion but we can't figure out what is causing it. I have 2" headers into 3.5" collectors out a full 3" exhaust. I also have electric cutouts spliced into the collectors and I run "open headers" 95% of the time. And this motor was freshly built 5,000 miles ago.

Would not running through the exhaust limit the backpressure necessary to fully pull out the exhaust gases from the cylinders and instead it's staying in and leaking up into the intake side? Might a cam with more exhaust duration help this?

I welcome comments.

 

[69Bee]

This a normal occurrence. Just because it was rebuilt 5K miles ago, doesn't mean it was done correctly, or that the engine break-in was done correctly. Loose guides and rings will allow more oil into the cylinder, and this is the result.

 

[HEMI-ITIS]

Those 2 valves came out of the same head??? Why were the heads taken apart??

 

[snakeoil24]

Looks like bad guide.

 

[440beep]

Yes, same head, and the one is the exhaust valve. Took heads apart to put new valve springs in.

Those 2 valves came out of the same head??? Why were the heads taken apart??

 

[440beep]

Well, it'd be bad guideS, as all the intake valves were black like this one.

Looks like bad guide.

 

[fishmens67]

Looks like bad guide.

could be this or a leaky intake gasket. I'm leaning toward a bad ring seal.

 

[dvw]

That is oil. Intake to head, valve seal/guide, or ring seal. One of the three.
Doug

 

[lewtot184]

That is oil. Intake to head, valve seal/guide, or ring seal. One of the three.
Doug

this! something ain't sealed up. reversion would be more prevalent with exhaust back pressure (mufflers).

 

[PurpleBeeper]

That is oil. Intake to head, valve seal/guide, or ring seal. One of the three.
Doug

I agree. If the bottom of the intake runners look dry, then valve seals or guides.

 

[brian6pac]

PCV valve sucking oil fumes into intake

 

[brian6pac]

Run your breathers into your header collectors

 

[HEMI-ITIS]

How many cylinders look like that?

 

[Danomt]

A leakdown check would have been good info. I suspect guides/seals. If smoke for a minute after start up , still guides. If smokes on major deceleration, then maybe rings. Put it back together right and all will be good.....

 

[AMX364]

Valve stem seals leaking oil past. Question is why? Valve guides or poor seals. On mine I ended up using Perfect Circle seals which fixed my valve build up. Had to buy the special tool to cut the stems for the seals. IMHO

 

[440beep]

Unfortunately all 8. Perhaps this is what I get for using "certain discounted" heads. We're installing new guides which are hopefully of better quality. My builder is of the highest quality and he knows what he's doing, so I'm thinking perhaps it's the parts I'm using. Maybe it's time for the Trick Flow heads.

How many cylinders look like that?

 

[440beep]

Oh yes, my bad and over analyzing. Guess back pressure would be nonexistant running straight out the headers.

this! something ain't sealed up. reversion would be more prevalent with exhaust back pressure (mufflers).

 

[HEMI-ITIS]

Have them install some good seals and check the valve job

 

[furryfrog]

Sure look likes oil cake to me too. Are these perhaps stealth heads with the original installed valve stem seals? I did a cam swap on my motor and noticed a little oil cake build-up on my intake valves. I am running stealth heads with there supplied valve stem seals. Running water injection on my set-up so it should keep everything clean, especially the combustion chamber. My plugs sure are squeaky clean every time I pull them. Thinking about ordering a $20 bore scope to hook to my phone to periodically look at my intake valves. I plan to change my valve stem seals sometime....

 

[Cranky]

Just need a bit of ice cream with that cake Yeah, no use adding anything to this but reversion 'usually' is when you see black soot tracking back up the intake runner and even into the bottom of the carb. Restrictive exhaust and cam type can cause it but what you have is an oil control problem. If you mentioned what heads you're using, I missed it....and I'd also like to know what kind of valve stem clearance they have and the type of valve stem seals.