Oil Leak causes?

[Guest zfan]

My sbc 355 is leaking quit a bit of oil at high rpm's in the back area of block where heads,manifold and block meet. I also noticed it around distributor shaft seal. This is the high point of oil trail, my friends say it would not be from there but probably sending unit or manifold where block comes into seat.

 

Does anyone or has anyone had simular problems in this area. Local shop said it is not that uncommon for sbc to have this problem back there!

I guess I'll pull manifold and try to reseal as well as around distributor and sending unit.

 

Any Ideas or hints would be appreciated.

Mike

[fl327]

hey i just cured that! mine was leaking out the back from the rear of the passenger side valve cover and looked was gushing down the manifold heads and block and dripping down to my exhaust pipes! i dont know if its the same problem we have here but i switched to taller

valve cover gaskets and boom, all gone! hope this helps. Lenster

[Modern Motorsports Ltd]

So why can't it be your dizzy? Mines done that.....had oil pooling on my Victor Jr dizzy seals can easily leak......happens on mine if I leave it 'loose' too long doing a dizzy timing adjustment and happened on my wifes V6 camaro when a mechanic never replaced that gasket after doing some service for her when she was on a roadtrip alone.

 

Do the dizzy gasket first....it's easily done/cheap and a likely cause. Check that your intake bolts are all tight as well as your oil psi sender

 

HTH

[BLKMGK]

Umm, the distributor has a seal? Heh, do tell please! I'm new to SBC but my Ford never had any sort of seal - just drop it on and go. Wazzit look like?

[pparaska]

It's just a circular, flat piece of paper gasket material, with a concentric hole in the center - like a flatened donut .

[DavyZ]

Some of those nice MSD billet aluminum distys have O-rings to keep the oil from coming out. Nice!

 

Davy

[Guest Anonymous]

Yeah like Pete said. (Jim) Look in your intake manifold gasket box, its a little round donut looking guy, goes between the dist and manifold. (unless as Davy said your using a dist that has a O ring or something).

 

Theres several culprits for leaking back there, like Len said, valve covers, also the rear intake seal (did you use RTV or the seal without it (I did both)), the sender could be leaking a bit, particularly at high rpm's more pressure could weep, did you teflon tape it when you installed it? Is the sender itself leaking? Thats a possibility as well. Outside of cleaning it all up and then running it up to rpm and seeing, I'm not sure how else you'll find it.

 

Thats a few ideas anyway,

 

Lone

[BLKMGK]

Neener neener, I've got an O-ring! Want to bet it leaks?

[pparaska]

Oh yeah - if the block has been decked, the heads shaved, etc. the manifold can sit lower in relation to the cam and the distributor shaft inside can be "bottoming" on the bushings in the dizzy housing - causing it to not be able to sit all the way down on the manifold. Even if you have a gasket or o-ring it would still leak.

 

BTW, I have a complete Mr. Gasket set of nylon? distributor shims for spacing the dizzy up a bit (you put the shim under the gasket). If you need them, just holler.