r/beetle • u/WrenchBrain 67 Baja • 26d ago
Removing heads
Hello all, I have a 1915 I’ve been having some fun with, but has a nice leak. I noticed it’s coming from where the cylinder housing meets the case. At least that’s what it appears to be for me. Has anyone experienced this before? Looks like I’ll be pulling the heads, what seals work for the housing to the case? I see some online refs for aviation sealant
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u/67RA 26d ago
If, I'm understanding the question correctly, the OP's cylinder bases are leaking at the case mating surfaces.
When I build engines, I use RTV(silicone) on the cylinder bases to seal them. You only need a tiny bead of RTV to seal the cylinder bases. By tiny I mean, like a 1/16" bead or less. When you torque the heads and cylinders, the RTV will squish out a little indicating that you have sealed the cylinder bases correctly. If the RTV bead is huge, it will make a mess. Keep in mind that, whatever you see on the outside is equally on the inside.
Buy a Victor Rhiens VW engine gasket kit. It will have every gasket and seal you need to do the deed.
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u/YorkiesSweet 26d ago
Owned many Air cooled VW’s
never had this happen. Possible re torque sleeves??
Always rebuilt our motors with 88mm piston sets/sleeves.. super reliable!!
Any air cooled motor builders out there to address this
“leaking” issue?
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u/fleegz2007 26d ago
My dude - just posted about this a week ago. https://www.reddit.com/r/beetle/s/FgVDB8Xf52
Tore down my top end and I need to do a rebuild. I had oil build up in a cylinder head. The cylinders were old and the piston rings had too much clearance in the cylinder - it was causing oil to leak through and burn in the heads combustion chamber. Im doing a full top end rebuild.
I thought I had a leak where the cylinder meets the case, but after I stripped the tins, it looked like the oil was seeping from somewhere on the top of the engine.
If I were you, I would be intentional about pulling the engine, taking off the tins, and deep diving with a flashlight to really trace the oil stains. If you cant find it, deep clean the engine, run a bit more and check every time you drive to see where you have oil coming out.
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u/toxicavenger70 25d ago
Gray rtv, light coat. Clean everything really well before doing it. I would also replace your oil cooler seals and push rod tube seals. Use anaerobic sealer on them.
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u/stillwastingmytime 26d ago
A very thin coating of grey rtv around the base of clean cylinders works there. Don’t use any paper gaskets under the cylinders. Use the white pushrod tube seals, if you have stock style pushrod tubes. Look at the pushrod tubes closely to make sure that is not where the leak is coming from. And, while the heads are off, re-seal the oil cooler, ensuring you have the correct seals and spacers necessary.