Topic: valve seals
in Forum: C3 Engines
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Rochester, NY - USA
Joined: 6/12/2012
Posts: 95
Vette(s): 1980 L- 82 fully restored and upgraded.
I replaced just the seals on my C-4 , it was easy . And it totally solved the issue of start up smoke. The biggest challenge is getting the inexpensive tools , most parts people are kids so hit a napa or a well established store in your area, get a spring compressor and the hose you screw into the spark plug threads to pressurize the cylinder . Basic hand tools for valve cover removal new gaskets and new plugs because you pull old ones anyway ! Will take about 3 hours a side on average.
1980 , ZZ430 , 3.92 rear , 700R4 2400 stall NEW EZ EFI
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Book shows 6 hours for both sides....prolly pretty close, depending on if it has A/C, cruise control, etc.
Joel Adams
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book time dont mean youll have it done though them plugs are hard to get too. while your in there clean up the valve covers with some paint
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Overland Park, KS - USA
Joined: 7/9/2003
Posts: 914
Vette(s): 1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.
2023 Accelerate Yellow HTC Stingray
If you happen to drop a valve, you can retrieve it w/ a magnet that fits in the valve guide. Best to run piston to TDC before removing springs tho.
1973 L-82 4 spd
I dont know how much you like to work on engines, but the easy trick to change out
the seals is make sure the piston is down, pull the plug stuff the cylinder with nylon rope
than have the cylinder come up to hold the valve and from the top of the motor you can
compress the valve spring and remove the spring and keepers (make sure there is NO way
for the stuff to fall in the engine)...remove the seal put the new seal on..than reverse the steps
just a thought..
1975 Corvette Coupe
My first Vette.....trying to fix stuff
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Former Member
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Ormond Beach, FL - USA
Joined: 7/28/2012
Posts: 19
Vette(s): 77 coupe, yellow, auto, L series, A/C, T top, Grey leather interior. It is about 75% & matching #'s. The miles are 117K & intend on restoring bit by bit to enjoy Cruises & rallies in Florida , & maybe some shows ?
I know this sounds like going against tradition and it makes me a little uneasy. But, we used to put small block Ford valve seals to replace the little "O" ring Chevy seals that BRITTLE & BREAK up because of the high temps all the time. They fit over the top of the valve guide nicely, cost very little, & last a lot longer. You just need to make sure you fit them over the valve stem & they have a good amount of interference when you slide them down. I think we used to buy the 302ci. valve seals (bonnets) for this job. Hey, I know it is against all the unwritten rules. But you will never have to do this job again, I garranty !!!!
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Overland Park, KS - USA
Joined: 7/9/2003
Posts: 914
Vette(s): 1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.
2023 Accelerate Yellow HTC Stingray
Do those "umbrella" type seals allow sufficient oil down the valve guides?
1973 L-82 4 spd
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
The umbrella seals are fine, imo. That's all I've ever used. The idea is to keep excessive oil from running down the valve stem into the chamber thru the guides, not to keep any oil at all from getting to the guides. If you think aboot it, the little o-ring type seals are pretty much useless for anything other than lessening the amount of oil running down the stem after the engine is off. With the umbrella type seals, you will still get lubrication oil down into the guides. 
Most engines now have positive seals on the valves, that seal both to the stem, and the guide...
Most engines now have positive seals on the valves, that seal both to the stem, and the guide...
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Limited Member
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Overland Park, KS - USA
Joined: 7/9/2003
Posts: 914
Vette(s): 1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.
2023 Accelerate Yellow HTC Stingray
While the only umbrella seals I've seen were on a friend's 66 427, they were a tight fit to the valve stem. Not sure how any oil could get past them and down in the guides.
1973 L-82 4 spd
in Forum: C3 Engines
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