Distributor O-ring size? (type 4 engine)

[grandfatherjim]

Replacing my tired out 1700 with a fresh rebuild made into an 1800,



and really want this to be the end of oil leaks. I'm tight for time and I need a distributor O-ring in case that's the source of this:



Can anyone tell me the dimensions of the O-ring? I do not have time to order one but can go and pick one up someplace.

Thanks!
Jim

[grandfatherjim]

Update - immediately after posting I realized how easy it would be to take the old ring with me... but on removing it I see that it does not have a round cross-section. Is it supposed to?
Thanks,
Jim

[Gypsie]

My recollection is that it starts out round but will become squished and set into the shape of the void that it fills while it sits there heatin' and sealin'.

find one that fits the circumference and sticks out of the groove a scosh. I wonder if a small end pushrod tube seal would fit?

This is of course a temp fix til you can source the proper part. Did you buy an engine seal kit when you did the engine? Should've been one in there.

[Randy in Maine]

Buy this one as it actually fits and does not leak.

http://vwparts.aircooled.net/Distributo ... 05-261.htm

[SlowLane]

My recollection is that it starts out round but will become squished and set into the shape of the void that it fills while it sits there heatin' and sealin'.

Nope, it starts out with a "D"-shaped cross section, with the flat part of the "D" on the inner circumference of the ring. Regular round-section o-rings don't seem to fit in this slot very well and can make insertion of the distributor a real challenge if the ring thickness is just a skosh too large.

They eventually assume a rectangular cross-section as Gypsie notes, and then they get hard and brittle.

I could have sworn that some vendor (AirHead Parts, perhaps) was selling a Viton version, but I can't seem to find it. As long as your old one is still pliable it should be okay to use.

This is one of the few parts which are common to both the type 1 and type IV engines, so don't worry about sourcing a type-IV-specific part.