small-block stroker oil pan leaks

Posted By: cudasam

small-block stroker oil pan leaks - 03/24/10 03:09 AM

I have a 406 magnum stroker in an e-body, and I can't seem to stop the oil pan from leaking at the rear. I have tried a stock 360 pan with a one-piece magnum gasket, and then I tried a stock size aftermarket pan with a Mopar 360 LA gasket set. This worked great for a few days ,until my motor started to break in .it seems like when I started hitting higher rpm's, the leak started again. I have no windage tray, so is it possible the crank is spinning in oil under acceleration and getting forced out under pressure? Should I just bite the bullet and go with a Milodon low profile? Thanks.

Posted By: goldmember

Re: small-block stroker oil pan leaks - 03/24/10 03:26 AM

Quote:

I have a 406 magnum stroker in an e-body, and I can't seem to stop the oil pan from leaking at the rear. I have tried a stock 360 pan with a one-piece magnum gasket, and then I tried a stock size aftermarket pan with a Mopar 360 LA gasket set. This worked great for a few days ,until my motor started to break in .it seems like when I started hitting higher rpm's, the leak started again. I have no windage tray, so is it possible the crank is spinning in oil under acceleration and getting forced out under pressure? Should I just bite the bullet and go with a Milodon low profile? Thanks.

Changing pans isn't going to fix the problem. Any pan with straight rails and proper installation should work. Are you sure the oil isn't coming from another location? Rear main seal or even oil sending unit? Are you overfilling the pan? If so I'd stop it today.

Posted By: PAINT IT BLACK

Re: small-block stroker oil pan leaks - 03/24/10 03:45 AM

I had the same problem on my 408 on a small scale. I am trying a Milodon low pro pan now, but don't have it back in the car yet.... so I'm not any help...

Posted By: autoxcuda

Re: small-block stroker oil pan leaks - 03/24/10 05:12 AM

The one piece magnum type gasket doesn't fit the older blocks 100% correctly. Something about the corner to pan connection needing spacers.

I put one in my 360 and the rear cap to pan didn't seem right at all.

Posted By: 69Cuda340S

Re: small-block stroker oil pan leaks - 03/24/10 02:48 PM

If you didn't put a thin film of RTV sealer between the block and rear main cap it could be leaking there.

Posted By: Mopar73340

Re: small-block stroker oil pan leaks - 03/25/10 10:24 PM

I have the exact same issue with my 408. I have had the pan off now two times. The last time I used the Kevco pan and magnum gasket. One time it leaks alot the next time very little. I figure it has to be the rear main as everything else is dry. I've built plenty of small blocks (318's and 340's) and never had this problem. The worst part of the whole mess is it didn't leak a drop through 8 dyno pulls and then leaks as soon as installed in the vehicle.