This past weekend I was finally able to get the motor started. Recent v6 to v8 swap in to my 92. It is a vortec headed 350 from a 98' ck1500 (Truck) and was believed to have 28k miles on it. It had been sitting in my garage for the past year before I was able to get it in. It was believed to have been in good running condition when bought etc etc etc.

To my problem, motor is running and sounds strong, loud as hell running just the open headers However, about 10 seconds or so after initial start I got tons of smoke through the valve covers. I don't have pcv hooked up yet but did not have valve covers sealed so I don't think the crank case was just under pressure nor have I ever seen that much smoke through the valve covers that wasn't related to bad rings (blow by).

Obviously the next step (should have done before I ever dropped the motor in) is to compression test all the cylinders and verify what I suspect to be the issue. What I want to know is, is there ANYTHING else this could be? I won't have a chance to compression test till Wednesday and I'm really dreading what I may find. Is it maybe just normal for the roller motors to experience this without the pcv hooked up?

Would really appreciate some help here, some crossed fingers or something ya'll!

 

VALVE SEALS.

Time to pull the heads off.

 

lawn spork the guys yard that you bought it from

 

I thought if it was valve seals it would be coming out the exhaust, which it is definately not doing.

 

Lawn spork? what's that?
I bought a motor like that when I was young, had a hole in the piston.

 

Yep do a compression test. Also, if there are any cylindars out of the ordinary, you can pour a bit of oil in that particular cylindar, and run the test on that cylindar. If the compression then goes to what your other cylindars are, you know its most likely valve seals. If it still doesn't fix it, then it could be rings etc..
-Greg

 

Hook up the PCV and just drive it for a while. You said it's been sitting in your garage for about a year correct? The rings may be frozen from sitting. Drive it for a week or so and if it doesn't get any better do a compression test. While it's possible the valve seals are bad they aren't your immediate problem. You also don't need to pull the heads to change them.

 

If the rings are frozen would the motor be unusually hard to turn? While I was trying to get TDC for timing I was unable to turn the motor even with the biggest breaker bar I got by hand.

 

Possible. BTW, if you don't hook up the PCV you will have more blow-by. Hook that up and drive it.

 

I'll give it a shot, will probably still do a compression test later tonight when I get home from work. If for nothing else just so I have a reference point for if it does clear up. Thanks for your guys' help, I'll update when I know something more concrete.

Also, are there any oils/treatments that would be good for freeing up a suspect ring?

 

GM Top Engine Clean
http://www.sdpc2000.com/catalog/1015...8-cyl-18oz.htm

 

Run-on. Is that when you shut your engine off and it continues to try to run? (runs rough for a few seconds then shuts off)

 

Yes. Top engine clean helps dissolve carbon that can cause increased compression and glowing carbon allowing combustion without spark.