Rear Main Seal Tilt Test
 

I have installed the BOP one piece rear main seal. I have 6 quarts of oil in the pan and am doing the tilt/leak test. It has set over night and dry as a bone. I am curious if I have the engine tilted enough take a look at the picture and let me know if you think this is tilted far enough for a good test. Thanks.

I think that should do it. Here's how far I tipped mine back - and it leaked.

https://forums.maxperformanceinc.com...1&d=1670260391

BOP one-piece seal.

After sitting overnight with 5 quarts in the pan no leaks.

The next day it was broken in on the run stand and it ran for a couple of hours leak-free.

I had 6 quarts in the pan and let it sit overnight and not a single drop, it's bone dry up there. Let hope it stays that way after I get it in the car and I start driving it.

Mine was leaking with an hour or two so if you made it overnight, you're probably looking good.

Wade at BOP has mentioned that he doesn't think the tip test is reliable since some oil can get by the crank serrations. IMO the test seems to be a pretty good indicator of whether things will seal or not. I had the one and two piece leak on me with the tip test. The graphite seal is still dry after a few weeks.

Here's mine, left it there a couple of days, not a drop. BOP one piece.

I'd guess if the serrations are enough to let oil pass in the tilt test, they are probably large enough to trash the seal after running for a while.

https://forums.maxperformanceinc.com...1&d=1670271937

I inadvertently used the tilt test on a RAIV about 17 years ago. A friend had it built by a well known Va. builder (since retired), and he used the BOP one piece. It was hanging in the air between the fenders with the 4 speed attached, when a steady stream began to run off of the bell housing. Back on the stand! The builder drove down and replaced it again, and it leaked less! He blamed it on the serrations, so I guess that's a popular excuse.
About a year later we pulled it out and shipped it to the guys in Tenn. to be built again. Same crank and no leaks.

The final test will be when I start driving the car fingers crossed. Thanks for all the responses.

Tilt test won’t tell if it will leak or not. After a day of tilt test, with no leaks, my one piece seal leaked like a sieve with the engine running. Wasn’t the seals fault, it was mine. Rushed the install trying to make a NMCA race two days later. Very important to follow BOP’s installation instructions to the letter.

Not aware that the 1 piece seal was around from BOP that long (17 years).

Tom V.

Are you saying the builder used the one-piece RMS 17 years ago? Did you mean the two-piece? The one-piece wasn’t available that long ago.

Having been that long ago it very well could have been the one piece. The engine was strong with no issues, but leaking at the rear main, being why it was removed. Not my intention to cast doubts on the reliability on the one piece. The mention of serrations is what drew my attention. My apologies to Wade or anyone else taking offense.
I don’t remember what I ate for lunch that day either. I do remember Tom talking with the builder the following year at VMP though.

Yeahhh. CRS has been trying to get the best of me, here in last 3-4 years, I'm not giving in!!!

I'll just throw this out there. Another issue with rear main seals is blow-by. Seems to me when increasing H/P on these engines and higher rpm's tends to create more pressure in the crankcase. I've seem oil dipstick pushed out more than once. I guess making sure your PCV system is in good working order. Or running a vacuum pump in the case of higher H/P, Torque and RPM's. Just saying. I'm hoping it's all works out good for you also Tim.

FWIW my 1-piece rear seal leaked badly for a year but has stopped leaking the past few years. Dry back there. Wore-in? 103 cast crank.