I just finished installing my new (built)motor and when you jump in it pretty hard it puts a lot of oil out the blow by pipe. Enough to coat the bottom of the truck rather well if you are going fast. Is there a simple easy way to combat this. I had a drag racer tell me that they run vacuum pumps to vent this efficiently. Any help is appreciated.

How much piston to cylinder wall clearance did you have? Ring end gap?

X2 on the clearances, Also are you running forged pistons? most big motor build have alot of blowby

mine has ZERO blowby...

FWIW...

Piston clearance is six thousandths, mahle pistons, twenty five, twenty, and at least 12 thousandths ring gaps. All these tolerances are what Guy recommended. We have done some more looking and it may be an oil leak. We need to dial back the adj oil pump. After I posted this we put an manual oil press gauge on it and if it is fairly cold and you back it out the drive it will put the gauge clear up to 150. We set the pump to what should have been 65 psi but it is way higher.

could it be your injectors?

I bought brand new GM injectors from a member here and had them modded by extrude hone, so I don't think so. On a second look yesterday after re-routing the breather hose it appears to be a leaky front cover. It is so hard to tell after the fan gets done smearing it around so at first glance we thought blow by. I spoke with Curtis at DPR and we are working on dialing back the oil pressure with some mods to the relief valve. Also special thanks to Tony B for his info even though all I have bought from him is a set of traction bars. Great guy.