horist

It doesn't happen all the time... no coolant in the oil... motor is stock. I have run about 120lbs of nitrous through the car (100 shot)...

Only occurs after the car has run for a while (seems over 2 hours) and at high speeds (seems to be over 100mph). Several people have suggested it may be PCV blowby problem... but I dunno...

Havne't done a compression check yet

What do you think it could be? I'm planning on replacing the ENTIRE top end (only stock parts should be block, crank, rods, pistons, and maybe a few parts I don't know about) this winter... but this smoke is pissing me off...

it's only happened on 2 occasions, but once it starts, every time I get on the gas at high MPH it does it again... and you can see it out the rear view mirror.

thanks

Edit: Smoke appears white from inside the car.... but at the speeds it occurs i'm paying more attention to the front than the back.

Is it possible to have a VERY small crack in hte head gasket, and it only is opening up enough to let coolant through at high speeds (high combustion chamber pressures)

<small>[ September 27, 2002, 11:41 PM: Message edited by: horist ]</small>

LS1derfull

Yes it is possible to have coolant seepage from gasket,do a cylinder leak test on each cylinder and check for bubbles in coolant. Also all LS1 motors have inadequate pcv system baffling because valvecovers are so shallow there is no room for it.It is necessary to do this externally, the best way is to use oil separator/filter for paint spray gun application.Install this after pcv valve but before port on intake manifold.

wrencher

iTrader: (2)

When it smokes after you give it gas was it closed throttle no gas? Do you have a spark knock issue at hi-speed? High milage motor, the stock pistons leave alot to be desired.

horist

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wrencher:
<strong>When it smokes after you give it gas was it closed throttle no gas? Do you have a spark knock issue at hi-speed? High milage motor, the stock pistons leave alot to be desired.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">well... not sure about the spark knock issue, not sure what that means.

It has occured both under gas and when I let off... today at the drag strip it happened when I let off.

I was getting 3-5 degrees of KR up top today... and my mph is way down.

Motor has about 40,000 miles on it

I think my valve train is pretty tired ... when I first got the car I knew nothing about cars and figured a mere 600 RPM was nothing... so I was shifting at 6600 RPM (hpp3) for about 75 runs....

I'm planning a top end rebuild this winter.... hopefully the bottom end is ok (no weird noises, no rod knock....)