Heads leaking oil

[elansmith70]

Just coming to the completion of my Buggy with a single port engine but the heads have started leaking oil. Why? I found a similar older post but need clarification.

Way back when (before the body was on) I took the heads and barrels off due to bad running and discovered broken rings on number 1. I replaced all the rings, new push rod tubes and seals, heads back on. Test ran engine a couple of times, no problems.

Obviously, now everything is together issues are popping up. What is oil doing in the combustion chamber to be leaking out? Why oil rather than gases? Leaks when running. Drips when not running.

Compression test 1=130psi 2=135psi 3=140psi 4 135psi

Checked torques on bottom nuts (obviously tops covered with tinware) not changed, still okay.

Did notice when fitting the heads that the push rod tubes made it hard to tighten the head down and are completely compressed (no gaps) issue?

Thanks for your help in advance.

Cheers. Jason

[sjbartnik]

Where is it actually leaking from?

That's step one. Get your head under there and look. Pushrod tube seals? Valve cover gasket?

Pretty rare for it to leak from the actual head/cylinder joint but certainly possible if the heads weren't flycut, or if the cylinder heights weren't within a couple thousandths of each other on assembly, or if the heads are not torqued correctly, or if the sealing surfaces inside the heads where the cylinders seat were not clean on assembly. Some oil will always get into combustion chambers. Some gets past the rings, some is introduced via the breather as crankcase vapors containing oil mist get routed into the intake.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[mukluk]

You can also get oil leaks from the rocker area via the lower cylinder stud holes if you didn't seal the nuts/washers. Likewise, oil can leak around the rocker assembly studs if the seals are missing or bad.
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1960 Ragtop w/Semaphores "Inga"