[kenai9]

I have a ZZ502 crate engine with a Moroso oil pan on my 1969 Chevelle. I was reading through prior threads and found one on Oil leaks in BBC engines. I have a similar problem where the oil is leaking at the rear of the oil pan at the bottom of the lip where the oil pan meets the rear seal.

I purchased the engine in 2006, had it run on a dyno, and have about 700 miles on it. I was thinking of lowering the oil pan and applying sealant along the pan, but noticed that the advice from "BlownBBC" to the other thread was:

"Probably gonna have to take it apart. When I assemble, I put a little anaerobic sealant under the rear of the main cap then torque it down. Works perfect. The leak is caused from the oil being pumped through the cap into the block. The resulting pressure is "squeezed" out between the cap and block effectively bypassing the oil pan seal and rear main seal. New blocks, like a gen VI or bowtie, have an o-ring in there to correct this."

Does the zz502 have an o-ring to correct the problem? Will applying sealant work in my case? Has anyone else had problems with rear main seals in zz502's?

Thanks, Ed

 

[Ben Lurkin]

I have a ZZ502 crate engine with a Moroso oil pan on my 1969 Chevelle. I was reading through prior threads and found one on Oil leaks in BBC engines. I have a similar problem where the oil is leaking at the rear of the oil pan at the bottom of the lip where the oil pan meets the rear seal.

I purchased the engine in 2006, had it run on a dyno, and have about 700 miles on it. I was thinking of lowering the oil pan and applying sealant along the pan, but noticed that the advice from "BlownBBC" to the other thread was:

"Probably gonna have to take it apart. When I assemble, I put a little anaerobic sealant under the rear of the main cap then torque it down. Works perfect. The leak is caused from the oil being pumped through the cap into the block. The resulting pressure is "squeezed" out between the cap and block effectively bypassing the oil pan seal and rear main seal. New blocks, like a gen VI or bowtie, have an o-ring in there to correct this."

Does the zz502 have an o-ring to correct the problem? Will applying sealant work in my case? Has anyone else had problems with rear main seals in zz502's?

Thanks, Ed

Yes, your block already has the o-ring between the rear cap and the block.

 

[Dave427]

The Gen IV BBC rarely have leaks at their one piece rear main seals.
I would try re-torquing the oil pan, if thats not it, sounds like you need another pan gasket.

Dave

 

[Big Mike's Garage]

I have a Moroso oil pan too that developed a leak along the bottom edge of the pan, it was welded while on the motor and in the car. Oil was drained and pan was welded fresh oil put back in no leaks. I was at a show and had talked to a Moroso person and he told me to take oil pan off and send it back to them like they knew there was something wrong with them in the first place but i never followed through with sending it back because it stopped leaking after it was welded.

 

[kenai9]

Thank you all for getting back on my post! I tightened the bolts on the pan as a first step. I am relieved to hear that the rear main seal should not be the problem. I changed the oil and started it up and let it get up to temperature (can't drive it yet as we still have snow where I live; Juneau, AK). I put some white board underneath it to check for leaks. A few hours went by and nothing yet. If a leak starts, I'll go with checking the pan.

Thanks again! Ed

 

[boz53bj]

I had one that leaked out the back corner of the head and ran down the block. We ended up haveing to put new head gaskets on and surfacing the heads.