Excessive blowby and oil leaks
 

I have now had this motor out 3 times this summer for oil leaks. I have been through a few crankcase ventilation choices and ended up with a -12 an line to a 1.5 quart breather tank with fuel cell foam in the lines to help hold oil. What it seams to be doing is blowing out part of the oil pan gasket and pushing oil out of the breathers into the breather tank. It now has pushed oil out of 2 different parts of the pan. Last time I had it out I pulled the pan, and I always use a felpro one piece pan gasket, used some rtv as well but this time blew it out towards the back passenger side. I also use studs on my pans and it is a 12 quart offshore milodon pan. Now I also have the whole Hardin Marine remote oil filter setup with 12 an lines as well and have used both a BBC oil filter and the giant nascar filter you can put on it. Both filter leak horribly at the gasket on the filter. I have used different brands with no luck. Anyone else have this issue with the hardin marine unit? Or have any idea on the possible crankcase pressure?
The oil pic is how much drained out of the breather after around about an hour plus of 5k runs with little stops for tuning.

Do a leakdown test.
You probably have excessive blowby on your rings.

Looks like water in the oil to me...is the oil on the dipstick the same milky color as in that second pic?? if so I would start looking at head gaskets or cracked heads

Stewart

Blowby is rings. Always was, always will be. Reversion gets water in them. They rust and stick.

agreed...does that oil not look milky tho?? if the oil is way over full with water it will cause blowby too

First thanks for the responses and I will be doing a leakdown test soon. This is a new build and probably only has about 8-10 hours of actual run time. The oil in the pan is perfectly clean and I have the specific $85 dipstick (lol) to go with this pan. The oil is milky in the catch can because it mixes with the condensation from the motor heating up. Unfortunately this has gone on since day one so it probably is a ring issue. Kinda of bummed as I have built many BBC motors and never had this issue. This is my first boat and seeing all the really clean bilges on this site had me so excited about having a sani oil free bilge because I hate any kind of leak so this has been a very long summer of clean up after clean up.

what ring pack did you use, final hone on the bores was ??

I used to have a lot of blow by and oil leaks until the motors got rebuilt.
I bought the boat with AFR`s in the 9`s.(powervalves in primary and secondaries) maybe even more but FAST only registers to 9AFR.
Washed out the rings and cylinders so check your AFRs but it may be too late.

Be that as it may, during the many attempts at leak free motors before rebuilds I found the one piece gaskets to be $hit, always pushed out somewhere (even after rebuilds). Using the 4 piece was better but
best advice I got From Eddie Young was to throw away the front and rear rubber gaskets just use the cork on the side and caulk the rest . I used Right stuff, works like a charm. No more blowouts and bilge is oil free.

I believe I used this ring pack https://www.summitracing.com/nv/part...7-35/overview/ and file fit each cyclinderwith all the correct tools. My machinist whom I have had for years and machined many drag motors for me honed the cylinders to the pistons I gave him. I cannot tell you off hand what it is is but the pistons I got from Icon had the skirt coating and the piston to skirt clearance was set to that specification. I have never used a skirt coating before you think that may be an issue? I have only heard good things though. I also know that he does use a very good honing machine and have not had this issue in the past, in fact the last dragster motor I built that he honed was one of the best sealed up motors I have run. Thinking end of year might as well pull it again and take a look plus I was not happy with a 5400 max rpm LOL.

Are they the right rings for those pistons? Or do they want metric rings?