I just finished rebuilding my 1985 trans am,
New 350 rollor motor, 8:3 to 1 , forged pistons, gapless ringspink rods,forged crank
Aluminum edelbrock performer heads, full rollor rockers, siamized runners,bored out plenum for 1000 cfm bbk throdle body 36lbs injectors,edelbrock headers, 3 inch flowmaster american thunder exhuast. Paxton sn93 with 10 lb pulley, accel gen 7 dfi. crane cam

I could keep going but ill just get to the point, then engines running great, have a front mounted intercooler, not yet piped up.my problem is when i accelerate hard with high revs, at about 3rd gear i start blowing oil smoke out the back of the car. is this from running too much boost of is there a bigger problem? help me please! summers finaly on its way and i dont thinki can go anouther year without driven my baby. its been 2 years of building.


will

 

did you brake in your new motor? if so how many miles on it? have you done a compression test with all the plugs out?

 

what type pcv system are you using? Are you venting it back into the intake(most common). Even with gapless rings there still is some blowby.

Are you knocking at all? Oil in the combustion chamber will make it knock real quick.

If your knock counts are ok(blowby), the backside of your tb blades aren't covered in oil(pcv), the other places are intake seal, hg seal....

You could run a pump if it's real bad. Mod your vc's to accept a crossover and a line to the pump to suck the pressure from the crank case.

If it's minimal run two valve covers that have the oil fill cap holes and put two breathers in them and eliminate the pcv line. The holes oil drain holes insode the heads are more than large enough to evacuate the crankcase........


HTH!

 

I vote for a messed up PVC...

 

Well on the driver side i still have a stock pcv valve running friom the valve cover to the intake, the passegnger side im running a large breather that runs to the exhaust evac pipe just after the header.

 

check the backside of your tb blades see if there is oil there. Not clear on the evac pipe you're talking about.

Definately get rid of the pcv to tb! Any blowby will cause oil to get in there cause knock(due to the crankcase pressure and just the inherent vaccum from the intake stroke) and if it's bad burn oil in the chambers....

HTH!

 

Well the pvc valve goes to the lower intake, i took the other off the trotle body a wile ago. the crank case evac i have is a pipe welded into the hearer and creates vac when exhaust passes, i have that running to the one valve cover, ill check the trotle blades when i get home.

 

Don't you gotta route the PCV to BEFORE the blower ?

 

I belive the way paxton wanted the pvc routed was to the intake of the blower. but i have had this blower on my original 5.0 h.o motor, and had the same problem, that was the first thing i removed, hopen it would fix the problem. thats why im thinking there is just too much boost, i feel that the 10lb pully is killing power, and causen the smoke, but i was looking at procharger systems and noticed there kits start at like 9 to 12 psi, and even have a kit for up to 20, if im blown smoke now i would not wanna see what 20 psi does lol.