oil in cylinder

flat 39

flat 39

Senior Member
What would cause one cylinder to ingest oil like this? Install rings backwards?
 

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Hmmmmm . . . if you have the typical 3-piece oil ring setup (2 rails and an expander), they can't go in backwards - there is no orientation. You didn't happen to check the compression before you pulled the heads did yah? I'd want to know if that cylinder was holding compression the same as the others. If the oil isn't coming by the rings, then the next obvious place is through the intake guide. It looks like it is the rear cylinder, so I'm wondering if your engine has the oil baffles installed in the valley area? Maybe you're throwing a lot of oil up into the valley - and a "loose" guide or one with no seals on it is pulling oil into the cylinder? What type of crankcase breather system are you running? Is it a stock 49-53 setup with the oil draft tube . . . or???? Just some things to think about . . .
 
B&S
It is three ring pistons and I did not check compression.
I will pull the intake and check the valve guide.
also, I am using a PCV system that ports into the vacuum port on an Offenhauser regular dual intake.
Thanks for your input.
 
flat 39 said:
B&S
It is three ring pistons and I did not check compression.
I will pull the intake and check the valve guide.
also, I am using a PCV system that ports into the vacuum port on an Offenhauser regular dual intake.
Thanks for your input.
Click to expand...

Are you running a late style 49-53 manifold that uses a PCV in place of the road-draft tube? The later system works bass-akwards from the earlier pre-49 system - lots of folks mix-match parts and then their whole breathing/venting system is compromised.
 
valve seal on intake, guide very loose in bore. I have seen this before and that is what it turned out to be. also would check to see if oil is draining back to oil pan from intake area, splash pans on the rail?
 
Bored&Stroked said:
Are you running a late style 49-53 manifold that uses a PCV in place of the road-draft tube? The later system works bass-akwards from the earlier pre-49 system - lots of folks mix-match parts and then their whole breathing/venting system is compromised.
Click to expand...

It is the '49-'53 style manifold with the PCV in the road draft port.
 
petehoovie said:
What's with those dings I see in/on the top of the piston?....
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I believe the dings are from a spark plug electrode that hit the exhaust valve. It seams that that plug hole was bored a little deeper than the rest. I now have a copper washer under that plug.
 
So does that mean the plug broke off and banged around the cylinder? I think what we're getting at here is there perhaps a hole or crack thru the piston crown? Jack E/NJ
 

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It looks as if it was firing which I wouldn't think possible with all that oil in the hole . Is it the stock cam , any vacuum port to that intake runner ? Is the motor level , meaning in its stock location and not raised excessively in the front ? Was the oil level correct ? Not relying on the dipstick but on amount installed .
 
Upon further investigation, It appears to be the result of a gunky PCV valve and a little over fill oil level. Waiting for new head gaskets to verify.
 
>>>What would cause one cylinder to ingest oil>>>>?

>>>>It appears to be the result of a gunky PCV valve and a little over fill>>>


But then shouldn't more than just that one cylinder be affected? Jack E/NJ
 
When a cylinder is passing oil by the rings a little will make carbon chunks, cover the top of the pistons , a little more will start washing the piston top clean around the edges, a lot of oil will wash the pistons clean

I have seen oil rings missing, the expander ends overlapping, pieces of rings broke off due to installation problems, std rings in .080 bores---- if that much oil is going in through the intake from the pcv there will be wet oil in the intake and port
 
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