Cam O-ring/Gasket leak after rebuild

kstylianos · 10-10-2003, 09:53 AM

I'm happy to say the rebuilt engine runs and drives pretty well!! I have not been able to really get on the gas too much around the back neighborhoods during the initial 3-4 mile drive, but it definitely has a lot more low end grunt than it used to.....bonus!!

I unfortunately have one small oil leak, right at the cam case --->cam tower joint on the right side.....getting some small drips on the heat exchangers. The left side is dry as a bone. I obviously need to replace the gasket and o-ring at this union, but just wondering what could be causing it to leak here? All 6 heads were fly cut .35mm and the cam towers and C's were not touched. I read that if there was more than a .5mm difference from stock shaved off, then the chain case will need to be fly cut or chain case-->block gasket deleted and used some 574 instead.

I'm hoping its either a kinked o-ring or gasket as the other side is not leaking and it appears the gasket it wet at the 5 o-clock position. If I were more than .5m off and with the cam chain under tension, that joint should be leaking a little higher. Any thoughts here?

As I don't want to do this again (timing the cams with the engine in the car is not going to be fun), are there any tricks to ensure a dry joint here? I used Curil-T on the on the o-ring/gasket initially.

Thanks for any help......

ChrisBennet · ChrisBennet's Garage

I'm not an expert (but I have made lots of leaks

) but I always rub a little sealant (Loctite 518 but Curi-T should work) into the gasket and put Dow Corning 111 on the big O-ring. Be careful not to pinch the O-ring during installation.
-Chris

kstylianos · 10-10-2003, 04:19 PM

Thanks Chris.

I'm gonna bump this back up.

Superman · 10-10-2003, 07:03 PM

Congratulations, Charlie! The gasket under the thrust ring with (I think) three bolts in it likes to get on crooked. It sags downward against the bolt, for example. This is bad because it allows oil to seep fromt he wet area into the bolt hole. From there, it gets out between the chain housing and the cam tower. It's probably important to clean the surfaces completely, and I use a spray-on copper dressing on those paper gaskets. When tacky, it holds the gasket in place.

\when you get it apart, you'll see what i mean. It's possible to put the paper gasket on in a way that allows oil to exit.

But that might not be the whole story either. I fixed mine and it still leaks. My heads were flycut as well.

Jim

rcwaldo · 10-10-2003, 07:26 PM

You can visually see how centered the aluminum plate is in relationship to the chainbox housing. Make sure its reasonably centered. Otherwise you may have to shim the chainbox or machine it depending on which way you need to move it.

Good luck!

kstylianos · 10-10-2003, 07:55 PM

Superman,

How much were your heads flycut? Are both side leaking, or just one? Trying to get a feeling of whats an acceptable limit.

During the initial install the plate looked pretty centered, not visually off to one side more than the other.

I'm going to be replacing the gasket and o-ring on the right side tomorrow and giving it the same Curil-T treatment. If it still leaks, I may delete the gasket, or have a local shop take care of it.......depending on the PITA factor.

RoninLB · 10-10-2003, 09:34 PM

was the rear of the chain housing sealed seperately where the idler pins stick thru?
huh... Ron

Superman · 10-10-2003, 11:08 PM

Don't recall how much was cut from my heads, but not enough to warrant cutting the chain housing, according to conventional wisdom. The right side is the only side leaking. Ron has a point. Those pins are supposed to be epoxied. My housings were powder coated, so the factory epoxy may be cracked from the heat of the PC process.

kstylianos · 10-11-2003, 07:42 AM

Ron,

Yes, the rear of the chain housing were re-epoxied (JB-Weld). I can clearly see that the leak is right by one of the bolt holes.

Thanks guys.....

RoninLB · 10-11-2003, 09:50 PM

Quote:

Originally posted by kstylianos
Ron,
I can clearly see that the leak is right by one of the bolt holes.

wow.. that's enough to keep me on the lookout when I start minor surgery soon..

but the good news is that the preforated metal engine comp liner got installed today.. looks OK.. I think it has potential.......Ron