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Leaky engine poll

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Crank case has three pressure releaf tubes, one on valve cover to the air cleaner, one from tappet chest to the ground and one from the mech. fuel pump mount to the ground, minimani unit. No back pressure at all.
 
Well you know me. Off the garage I went and cut my oil pressure spring down. Now 55 cold and 40 to 50 hot. Idle still 20 or so, good fit on bearings.

Has been 30 min or so but I see no oil leakeage YET.
 
Its not so much that the oil is pushed past the scroll seal by excessive oil pressure, rather that the crankcase backpressure blows the oil past the seal. A 1275 with proper ventilation(negative pressure via gulp valve) that doesn't leak at the rear seal will start leaking right away if you disconnect the gulp valve and open the crankcase to the atmosphere. A little dab of suction to the crankcase will dry up a lot of leaks.

Glen
 
I have no back pressure at all and in fact have a bit of suction. Maybe I need a bit more. Remember that 948s have no gulp valve or anything else restricting open breathing.

Went out and put 6 or so miles on it. We will see. Did note that my oil pressure guage needs replaced. It is not the Mk I guage it is MK II and is now kind of jumping around a bit.

Guess I need to bite the bullet and have a real Bugeye one rebuilt.
 
Has been two hours now since I parked Miss Agatha.

I have a spot of oil the size of a nickel.

Hmmm, oil pressure at or withing factory range is good it seems.

Will let you know again this evening.
 
Big fat yes on the crankcase pressure. I picked up a Fiat 124 in Jacksonville, FL several years ago to drive back to Oklahoma. DPO said I needed to take some extra oil as it had suddenly started "using." First day I made it to New Orleans but added over a full case of oil on the way. That's about a quart per hundred miles. Figured out the next day that the DPO had recently "de-smogged" the engine and plugged the crankcase breather hose to the intake manifold in the process. Reconnected that hose and drove the car another 5 years or so without ever having to add oil again between changes. That engine also had proper seals at both ends too.
 
Okay, I got home from work and took her for a drive. I have similar oil pressure as Jack. Maybe slightly higher (by 5 pounds at most.) I am getting the majority of my leak from the front of the motor. I believe it to be coming from the timing cover seal. The only vent that I have running from the motor is from the separator to a K&N breather.

Suggestions to try and fix the problem first?
 
Drop the oil pressure. Not a deal, Pull the spring cover. A one inch wrench/socket works. Cut a turn off the spring. Only effects the max oil pressure, will not effect idle as that is bearings.

After three or four hours I have a spot on a peice of smooth metal about the size of a half dollar. I think I can live with that.

For my next trick I am going to close off the manual fuel pump breather and see if I get a bit of negative suction on the crankcase to help a bit more.
 
They don't leak - they mark their territory!
 
I don't mind em marking their territory Tony, it's just when they make a big mess doing it.
 
Yeah, mine is making a big mess every once in awhile. I don't mind the small drip out of the tranny. I just don't want it leaking from where it is not supposed to.

Jack,
Do you think that cutting a turn out of the spring will take the leak away from the front of the engine?
 
No I don't. I think I had too much pressure and it pushed oil from the rear bearing right past the scroll.

I think the front seal just keeps splash from getting out. Think about how that is put together and works. No pressure on the front seal at all. But oil pushes out the rear of the rear main bearing and if enough of it it will seemingly push past the catcher thing and overwelm the scroll seal and drip right out.
 
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