Got a 2wd cossie, new engine- new 200 block, long studded, ported head, new t34 with .48 exhaust. Running stg 3 (only 20lb/ft as i'm waiting to get it mapped), 500 ic and a pace breather/cache tank.

The engine is vented in 3 places, below the turbo at the base of the block, cam cover and just after the metal kidney/ flame trap. The return to the inlet manifold has been removed aswell.

When i'm running along the motorway, and i totally close the throttle and then bring the rev's down (by braking for example), i reopen the throttle i get a large puff of white looking smoke. If i drop the car into neutral, slow down and then select the right gear i don't seem to get the smoke.

The boost gauge (when the throttle is closed reads - 12 to 13 lb/ft)

I'm not using coolant but i am using oil. i'm currently running 10w40 comma xt2000. Possibility of oil thinning out when it gets up to temperature??

Any suggestions???????? I feel like i'm

Cheers

 

I would use 10w60 (castrol rs or tws motorsport) or mobil 1 motorsport, but hear what experts have to say.

 

did you renew the valve guides

 

Cheers for the replys chaps.

The guides haven't been changed - to my knowledge, but it was a secondhand head. If it were the guides, it would smoke more often than that- surely??

 

i had exactly the same problem, it was my valve oil seals(well shot they were, found some pieces of them in the sump)

Good luck

Ste