maybe hurt the motor

:mad:Ok guys had a issue this Saturday last sand drag race of the season, was making my first time trial run come up to the starting line at about 170 degrees motor temp a little cooler then I normally like the motor to be but it was a really cold night. Launch at 5300 at into second gear maybe 20 feet into the run and about midrace hit 3rd and that’s when I had a issue hard a pop and oil everywhere couldn’t see out of the windshield shut the truck down and get taken to the pits as were looking to see where a the oil came from can find anything obvious but its dark out.
Sunday morning wash the motor down to see if I can see anything but still can’t tell were the oil came from it looks like it came from up front but can’t tell from where. I’m thinking it blow the seal between the intake and block china wall but it still looks ok. My question is how much crank case pressure would it take to do that and would the colder oil temps have also played a factor in it letting go. I was able to start it yesterday morning and the motor was holding 55 lbs of oil pressure. I do run a exhaust evac system to try and help any ideas what I should look for when I tear it down. the motor is a 552 14.1 compression running Alcohol

Are you using the gasket on the china wall or RTV my 460 the 1st time I built it I used the gasket 1st time on track with it  blew the gasket out. Now I only use RTV and have never had it to blow out like the gasket I am also running a 552 with 14.7 cr on alky turning it 7000 with no problem. But I do run a electric evac pump what I like about the electric evac pump is I leave it running after I shut the engine down to pull any moister that might be in the engine crank case. Rings might be getting worn and building more crank case pressure might be one thing to look for.

im using RTV
its a freash build maybe 30 passes on the motor but at 300 feet at a time I might have to go electric on the pump if the exhuast evac system isnt pulling enough vac

Check the oil filter? Cool oil is thicker.....

it looks like the oil came from up top there was a lot of oil on top of the timing cover

the dip stick tube has blown out before maybe a inche but hardly with worring about,
but could i be building that much crank case pressure without having a bad running motor its a new build with maybe 35 passes on it from the sand drags 300 ft.

Also check your valve guides if they have alot of ware they can be letting in compression on the exhaust side

muddog899 wrote:the dip stick tube has blown out before maybe a inche but hardly with worring about,
but could i be building that much crank case pressure without having a bad running motor its a new build with maybe 35 passes on it from the sand drags 300 ft.

very possible....

I plan to do a compression test and also a leak down test to see if that gives me any clues before i tear it down for a look see hopefully nothing major.

If you dont find anything i'd suggested a good vacuum pump.they help keep moisture out when running alcohol.

Header evacs are junk imo, fuel vapors in the crankcase from cold temps.... One of the antibackfire checkvalves hangs open, little pop out the header and boom....