Okay gentlemen, a little scenario for all of you to mull over. My LG4 has 126,000 on it, and I have never noticed any smoke except for startup (the good ole' chevy valve seats) and at WOT (rich carb. setting). Last week I tuned up my car using Accel 8mm wires and Delco plugs. I also changed the oil, Castrol 10w-30, Delco filter. Since then I have been noticing whitish/purple smoke when I take off, and more than usual at startup. It may just be that I never noticed it before, but I dont think I would have missed it. God I just hope its not the rings going.

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---Grady---
1984 Berlinetta.
LG4 305, 150 hp.
Rochester Quadrajet(Comp. Controlled)
TH-700R4.
Flowmaster 80 series/ 3" cat-back pipe.
Accel Superstock Coil.
7.5 10-bolt rear/ 3.08's.
Edelbrock signature series air cleaner -w- K&N Filtercharger.
Pioneer head unit, Pioneer front 4X6's, Cerwin Vega rear 6x9's.
Daily Driver.

Personal Quote: "The Rice-Boys all tremble with fear when the old American V8 draws near."

 

It's probably a combination of both, to some extent. Usually the vavle guide seals (intake side) are the biggest offender in this area. The rubber or whatever they make them from gets brittle from years of thermal cycling (hot, cold, hot, cold....). A new set of aftermarket push-on intake seals will help get rid of much of this. The factory used to use ONLY an o-ring at the top fo the valve stem and a metal "shedder" around the top of the valve spring to create basically a big "umbrella" (not to be confused with aftermarket umbrella seals) to keep oil from running stright down the valve stem and into the vavle guide. The rubber o-ring is the part that fails.

Later factory heads use the above seals PLUS a push-on style seal on the intake side that clamps onto the top of the valve guide boss and provides a positive seal around the valve stem where it enters the top of the guide. If your heads don't have this seal already- ADD THEM! They can make a big difference in oil consumption. If your heads already have them, replace with new ones- the rubber is probably hardened and worn out. Don't use them on the exhaust, however. Stick with the regular factory o-ring and shedder arrangement only. Exhaust valves need more lubrication than the intakes do.

Probably won't fix the whole problem, but rings can wait until you are ready to do a full rebuild. And rings will usually produce noticable smoke CONSTANTLY, even just sitting at idle you'll get a slight "haze" out of the tailpipes.

 

So basically, until it is putting out smoke all the time, I need to worry about replacing the valve seats. I've never done it before and I hear its a toughy, any tips?

------------------
---Grady---
1984 Berlinetta.
LG4 305, 150 hp.
Rochester Quadrajet(Comp. Controlled)
TH-700R4.
Flowmaster 80 series/ 3" cat-back pipe.
Accel Superstock Coil.
7.5 10-bolt rear/ 3.08's.
Edelbrock signature series air cleaner -w- K&N Filtercharger.
Pioneer head unit, Pioneer front 4X6's, Cerwin Vega rear 6x9's.
Daily Driver.

Personal Quote: "The Rice-Boys all tremble with fear when the old American V8 draws near."

 

back to top, still need some advice

------------------
---Grady---
1984 Berlinetta.
LG4 305, 150 hp.
Rochester Quadrajet(Comp. Controlled)
TH-700R4.
Flowmaster 80 series/ 3" cat-back pipe.
Accel Superstock Coil.
7.5 10-bolt rear/ 3.08's.
Edelbrock signature series air cleaner -w- K&N Filtercharger.
Pioneer head unit, Pioneer front 4X6's, Cerwin Vega rear 6x9's.
Daily Driver.

Personal Quote: "The Rice-Boys all tremble with fear when the old American V8 draws near."