383 LT4 with paxton supercharger problems

Old 10-21-2007, 04:35 PM
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Default 383 LT4 with paxton supercharger problems

Ok here is the deal. My father bought a Corvette that has a LT4 thats now a 383 and setup to run a paxton supercharger. When we got it, the charger wasn't all hooked up and there was no instructions. Although we was told that it had been run on the motor before. After getting it hooked up, it started and ran fine, but after geting on it a little discovered oil leaks. 1st up was the dipstick and it was resealed. 2nd was the rear seal so it and the oilpan was resealed just for safety and to check the bottom end. After all this we got it together it blew the rear of the intake out and spits oil out if you get on it just a little. It was taken off, new gaskets, the ends cleaned and new silicone was installed. Everything was fine again until he stepped into it and the rear of the intake again blew out. 3rd time and again it blew. What hoses need to be took off, added or what? I'm not up to date on superchargers, but blowing the seals out tells me there is too much pressure in the motor. Compression is around 140 across the board, has eagle bottom end and JE pistons. Does anyone have an answer to where we are getting all the internal pressure from and how to fix it? Thanks for any help[/b]
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Old 10-22-2007, 12:16 PM
Join Date: Sep 2005
Location: East Texas
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What do you have for your block ventillation? i.e. Are you running a PCV valve, or open breathers, or do you even have your valve covers vented at all? My immediate inclination is your not venting or need to replace the PCV valve. If a new valve doesn't vent it enough, go to a filtered breather. Your building pressure in you crankcase, either by too much blowby at the piston rings, or just normal pressure not being relieved.

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Old 10-23-2007, 09:38 AM
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install the proper e-vac system...4 vane moroso should help if not eliminate this problem...have about 500 to 800 to send ..depending how much of the kit you need..

Also before you go doing all of this you should check the size heads you have and the exhaust..the most natural way for exhaust to exit an engine..if you cannot get it out of the exhaust fast enough it will find its own way out such as intake gaskets, rear seals.etc......

after you go here then check on the pump deal...you need the pump irregardless IMO.

thanks- Brian

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Old 10-23-2007, 02:18 PM
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you need the pump irregardless IMO.
What they said!
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Old 10-24-2007, 04:51 AM
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Thanks guys. The motor is running the stock aluminum valve covers and they are not vented. The PVC is almost new. There is 1 line from the throttle body running into the only hole in the valve covers and I thought this might be a direct pressure point. We will try venting the motor with a different set of valve covers and bypass the line I spoke of. Since this is just a everyday street car that my father wants to drive, the vacuum pump option is out. I wouldn't know where to put it anyway, since it has all the options on the drivers side of the motor and the blower stuff on the passengers. He's just wanting to be able to drive it mostly normally and get on it on occasion without oiling the motor and headers down. Thanks again for the replies.
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