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Am I correct in assuming this is probably valve guides?
The o-ring valve seals rotted off once already a few years ago and were replaced with push on umbrellas. Runs terrific though.
Slightly off-topic but it is my corvette parts hauler. One family owned with sentimental value.
93 4.3 S-10 150k miles. TBI
Do not know if it is a vortec or not. Do believe it is a roller block. Basically 3/4 of a SBC of similar vintage. But outside of my area of experience
Here it is in all it's purple paint with my corvettes 454 aluminum head LS6 in the back!
Last edited by leigh1322; May 1, 2021 at 10:06 AM.
Iron guides dont last very long in a SBC or the 6 cyl variant. Worn guides or not, the rubber O-rings are very inexpensive and fairly easy to change. Ruber umbrellas are the other easy option but its hard for me to believe they will last very long. You can do both to strech out the miles till the next major servicing.
So you are saying it starts showing blue smoke after it starts and warms up or do you see the blue smoke at startup and it goes away? Blue smoke at startup is usually valve steam seals and blue when running is usually rings. That's not 100% all the time but it the most common causes.
could also be valve seals loading up at high vacuum idle and puffing as soon as you hit the gas. and if valve seals don't fix it the answer is... "smoke? i don't see no smoke!"
Last edited by derekderek; May 1, 2021 at 05:57 PM.
It doesn't smoke when you drive it or get on it. It might puff a little at startup sometimes. But I let it idle 5 minutes the other day and it puffed a pretty big cloud when I drove away. Cleared up in a block or so. Pretty embarassing for a car guy!
We replaced the broken o-ring seals 7 years ago, and put umbrella seals on it at the same time. They are probably shot again now. I am assuming the valve guides are worn and that is what is killing the seals. Since it seems to be a weak point on a SBC. These heads are basically the same just 3/4 in size! LOL
I suppose I could just put seals on it...again....but it will probably still smoke some....and it's not the "right" way to do it.
But I really don't need another project right now. Trying to concentrate on the Vette.
If you do end up swapping out the stem seals, look for some quality umbrella style. Those rubber "O" Rings are around $5 for 100 pcs. What does that tell you?
Check out Summit for seals. Look for a viton (sp?) that does not require any machining of the guide boss. The quality units slip on and stay on.
Look for something around $26 a set or more.
If you do end up swapping out the stem seals, look for some quality umbrella style. Those rubber "O" Rings are around $5 for 100 pcs. What does that tell you?
Check out Summit for seals. Look for a viton (sp?) that does not require any machining of the guide boss. The quality units slip on and stay on.
Look for something around $26 a set or more.
Viton is correct. Viton is the brand name of synthetic rubber and was invented by DuPont I think in the '50's. We use Viton o-rings in our machines for a lot of applications. It's tough and can withstand many different gasses and chemicals. Has good heat resistance and doesn't deform or dry out like natural rubber.
Last edited by theandies; May 2, 2021 at 10:40 PM.
Blue smoke after engine idling
