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53 Hatt, with two 12V71 TTIs, Started getting oil out of the Airsep catch tank that drains the blower boxes. I just pulled the turbo discharge pipes to the blowers off and I am not getting any oil leaking from the Turbo seals so I suspect that a blower seal may have given out. I am getting about a pint an hour out of both blower box drains at idle. I sthere any other source of oil that can get into here besides a busted oil ring?
Allen
Those are the two most-likely sources.
BTW a pint an hour is pretty bad. If you lose an oil seal entirely on the blower you can get an oil-fed runaway - I'd look into that pronto.
Needless to say having a blower overhauled is cheaper than a teardown.
It donīt get any better, Installed new blowers, same problem. pulled blowers back off and air box covers, # 5 pistons on both banks were black from overheating. Pressured up oil system with the oil change pump and they were bleeding oil into the Vee. The two pistons were starved for oil. Pulled # 5 main cap and found lower half of shell was missing babbit and copper. Top of bearing shell is in good shape, Crank looks good. Mains on either side of 5 look like new. What could cause half of a bearing to flake?
I am doing everything I can not to have to remove this block and crank from the boat.
Allen
Sounds like you got some sort of oil passageway obstruction. Those are nasty and can be "migratory" (whatever is blocking it may or may not always block the passageway), but you have to find it or you'll just cook the replacements.
Crank looks ok with that much damage on the bearing? Uhhhhh... how carefully can you inspect it with the access you have?
This doesn't sound like fun at all.
Quote:
Originally Posted by SLIDELLBIGAL
Hi Allen, I dont think that you're explaining the problem correctly. The pistons are black from oil starvation? #5 main cap? Do you mean #5 rod cap?
Kiwi
The number 5 pistons on both banks are fed oil from the number 5 Main bearing, the oil travels from the main through the crank to the rod throws, then oils the rod bearings then through the rod to the piston pins and to the spray nozzels that cool the underside of the piston crown taking away heat. When the lower half of the bearing failed, metel went up the rods and clooged the nozzles causing the pistons to get hot and start galling in the liners. Today we blow air in the oil gallerys and see if there is an obstruction to the # 5 main bearing.
Allen
N/M - you answered it.
Quote:
Originally Posted by SLIDELLBIGAL
Thank You Allen, for the more detailed explanation.
After having several hundred engine rebuilds under My belt, I can tell You that if Your theory is correct about plugging the small end rod nozzles up from a main bearing failure, that babbit had to run thru the rod journals rendering them in need of resizing.
I have chased oil galley obstuctions before, to no avail and would'nt consider it possible on an original motor. If prior rebuilt then maybe but doubtful. The problem here is that the rod always fails first, from Your story that has not happened.
Please tell me about your chase results and prepare for the worst.
Thanks, Kiwi