so now i have the truck together and can get it to run if i hold the peddel down around 1000+ its ok but even at that im getting crank case pressure??? pcv tube is blocked off and i am running a catch can but dont understand the crank case pressure.
if i try to let off the peddle the rpms drop and die..

why cant this just work like its suposto...

8.1l whipple wtf

 

bump for the late night crowd

 

You are getting crank case pressure at idle -1000rpm?

 

Until you get it figured out run both valve covers to the catch can vented. A lot of people including me run it that way all the time. Some say they get an oily smell, and some don't. About once a month I think I smell something, and figure it's coming from there.

 

I just realized yours is an 8.1l so I don't know if that applies.

 

yea im running a catch can off the intake manifold.. found a spot thats connected to the oil filler neck that was perfict to tie into. i think im gonna try to hook the other side of the catch can to a better spot on the supercharger to get a bigger vacume through it. i think im getting pressure just because i dont have a good enough vacume pulling the air out but it could be excessive blow by. i hope not though because its a fresh rebuild

 

I would assume you are having excessive blow by. 8.1's are known for blowing oil. My brother had a suburban and a truck with 8.1's and they burned excessive oil. Everyone he has talked to has had the same problem. How many miles is on yours? I would apply pressure to the cylinder with compressed air, and see if you can hear it leaking in the crank case.

 

there is 0 miles on the motor just brake in time

 

Were the rings properly gapped, and installed? I would still apply air or do a leak down test.

 

i didnt file the rings to get them in if thats where your going with it.. they were sized for the piston bore so hopefully they are right.. just gotta get time to do a leak down test.. not as concerned with the pressure as i am not being able to get the truck to idle. unless i hold the throttle myself at a certain spot it dies