Well, this is the 3rd season with my engine build now @ 450whp pump gas and 493 on race gas.
I drove it the last 2 years as a daily driver, over 35k on it.

This year, after upgrading everything to make some bigger power (turbo, clutch, fuel setup) I put it on the dyno and it started smoking when warm. It smokes at idle and WOT when warm.
But if we let it cool down for 10 minutes and make a pass, it wont smoke.

We were at approx 380whp @ 10psi, just starting to make some good power. Then the car dropped 60whp without making any changes. It was smoking during that pass. When it wasnt smoking, the power went back up to 380whp again.

So, we checked a few things and compression. Compression was 180,180,190,190. could be alittle better, but that wasnt the problem. We decided to pack it up there and stop pushing it, just incase something happened. We were thinking it coulda been the turbo, the valve seals or a ring.

I took the car home and did a leakdown test. During the leakdown, nothing was out of the ordinary. One of the cylinders acted funny during the wet compression test. When we took the tester out after, it was smoking out of that cyl only. So naturally I thought the problem was in that cylinder. When I tore the motor apart, the piston that was in the smoking cylinder looked fine, the rings were fine.

We're pretty sure we ruled out the turbo, it has less then 4k on it and there was no sign of any oil in the charge pipes at all.

I run a very large battery sized B&R fittings catch can, with two -10 lines returning back to the block.

Now that I have it ripped apart and saw the rings in that cylinder, Im thinking it could be valve seals.

Other things I was thinking it could be was the oil Im using for the new turbo, its 10w30, but Ive always ran 10w30 in my car with no issues.


What do you think,

thanks

 

Usually if it's the valve seals the smoke would go away once it was warm and burned out. I guess if they are really that bad they could **** out all the time. What do the ports in the head look like? You would be able to pull the mani off after a pass and see in there for oil, that would tell you if it's in the head. If you checked the rings and they are good, then it's head or turbo.

 

looking in the ports on the intake, there is visable oil up there. I dont know if alot of that was from the wet compression test or not... I dont think.

If the valve seals were bad, there would be alot of oil sittin on top of the valves, right?

 

They are leaking. There shouldn't be any oil on the valve stems.

Replacing the valve seals will fix your smoking when warm problem.