DEL65
Of The Morons
Hi, I've got about 70 miles on the new motor and have been driving it regularly for the past couple of weeks. Runs great and and very fun to drive.
But, after I started driving longer distances and running thru the gears, I developed a leak at the back of the motor. Oil is slowly dripping down behind the rear of the pan and ifo the block plate. Enough to leave a about a 3" diameter spot overnight, or tiny 25 cent-sized spots when parked for 10-15 min or idling after driving for a while.
The flywheel is dry and no oil on the bell housing. It only leaks after driving and does not leak when idling or revving in neutral. I have a high volume oil pump that has about 30-40 psi at idle and 60 when driving. 10-40 oil.
To remedy, my engine builder replaced the 4-piece cork oil pan gasket with the 1-piece rubber one. He checked the rear main seal and it looked ok to him. He also thought that since the motor is new and still breaking in, excess pressure may be building up in the crankcase. He ran a hose from the left front breather back into the air cleaner to try to equalize the pressure. PCV on right valve cover to back of carb has always been hooked up. Still leaking; no more no less.
Questions: Is it possible the baffles in the tall Cobra valve covers are too restrictive and causing a pressure buildup? Should I change out the valve covers to see if that would make a difference? The current vacuum pressure is unknown.
Meanwhile, one of his mechanics theorizes the main seal was installed backwards, and they are thinking of replacing it. (I was a little irritated that they did not do it when they were had dropped the oil pan in the first place, but whatever.)
Are there any other sources for a what appears to be a non-pressure leak at the back of the block? Anything else we should consider? Thanks.
But, after I started driving longer distances and running thru the gears, I developed a leak at the back of the motor. Oil is slowly dripping down behind the rear of the pan and ifo the block plate. Enough to leave a about a 3" diameter spot overnight, or tiny 25 cent-sized spots when parked for 10-15 min or idling after driving for a while.
The flywheel is dry and no oil on the bell housing. It only leaks after driving and does not leak when idling or revving in neutral. I have a high volume oil pump that has about 30-40 psi at idle and 60 when driving. 10-40 oil.
To remedy, my engine builder replaced the 4-piece cork oil pan gasket with the 1-piece rubber one. He checked the rear main seal and it looked ok to him. He also thought that since the motor is new and still breaking in, excess pressure may be building up in the crankcase. He ran a hose from the left front breather back into the air cleaner to try to equalize the pressure. PCV on right valve cover to back of carb has always been hooked up. Still leaking; no more no less.
Questions: Is it possible the baffles in the tall Cobra valve covers are too restrictive and causing a pressure buildup? Should I change out the valve covers to see if that would make a difference? The current vacuum pressure is unknown.
Meanwhile, one of his mechanics theorizes the main seal was installed backwards, and they are thinking of replacing it. (I was a little irritated that they did not do it when they were had dropped the oil pan in the first place, but whatever.)
Are there any other sources for a what appears to be a non-pressure leak at the back of the block? Anything else we should consider? Thanks.
