Topic: Valve seals
in Forum: C3 Engines
Actually, when I do my seals, the heads will come off. I'm going to pull them, mill them a bit, and use shim type head gaskets. This will raise my compression from 8.5 to about 8.8:1 Granted that's not a lot, but it will help a little bit. I am also going to replace the cam, lifters, and valve springs at the same time. It's also going to get a set of ceramic coated headers, dual exhaust, and another intake. I'm keeping my Qudra-Jet. I will still use my stock torque converter, and have enough vacuum to operate everything.
Not major stuff, but I'm guessing it will produce about another 100 HP at the flywheel, maybe 70 at the rear wheels. I was going to do that after the body work, but decided it does make more sense to do the work in the engine compartment before painting the fenders.
Okay,
I went to buy seals today and they asked if I wanted the umbrella or non-umbrella type. I have no idea which are in the car now or waht the difference is.
Help !
Jim
Lifetime Member #73
The Money Pit.... and my niece
(click to see a slightly larger version)
The original seals are o-ring. They sit in a groove on the stem, and deflect oil at the spring retainer.
Umbrella seals go under the spring retainer, and sit on a boss on the top of the cylinder head, where the valve guide is located. They seal to the head, and then the valve stem goes thought the seal, and stops the oil.
Either one does a fine job, and you can make several arguments for either one. I used the Umbrella seals in Hanks car. Given a choice, I prefer them. If you want over kill, you can do both, but that's not necessary.
C3VR Lifetime Member #93

For some reason the first set of them I ever installed (many many years
ago were the Umbtrella Style... (Packard/Studebaker ) and that is all I have ever used since...
I honestly have 2 sets that I purchased last year that HAVE to be installed NOW.....another winter Project that I never started...
Winter projects seem to be put off more and more as I get older...
Heck I am retired and still put everything off... Now its spring and my yard looks like hell... dead branches to pick up, ton of pine needles and
leaves all over the place ..when I get around to uncovering the pool it will be nice and green ...
HELL.....The cars however all come out of the garage TODAY... On my way to Sams Club now to buy 3 cases of Motor Oil... The hell with the Yard. !
Bob Griffiths
Bob
64,72 & 98 Corvette Ragtops
76 & 79 & qa 88 ANC Corvette Coupes
Click on any image for larger view!
sit on a boss on the top of the cylinder head
[/QUOTE]
a boss ? Never heard of it...got a picture ?
[QUOTE=Ron 78]I was gonna ask the same thing,I was looking through my new Chiltons manual last night,and according to them ,small blocks only use the O-ring,and large blocks use the umbrella,wassup ?[/QUOTE]
I read that too...another reason why I'm baffled. That's what I get for researching.
Jim
P.S. The only reason my yard doesn't always look trashed is that the wife takes care of it.
Lifetime Member #73
The Money Pit.... and my niece
(click to see a slightly larger version)
A boss is nothing but a raised or machined section in a casting or part. On the cylinder head where the valve guide goes throught is a raised section. It looks about the shape of a wash tub or soup can. It's nothing but a cylinder of raised metal that is a cast part of the cylinder head. The seal pushes down on the cylinder of metal, and stick/seals there to hold it in place. Just push it on. The valve stem stick up through the center, and as such through the center of the umbrella seal.
If you are blowing smoke on startup,and on decelleration,but not using much engine oil,and you have an auto trans,it could be the vaccuum modulator valve causing trouble.I initially put o-rings and umbrella seals on but it didn't stop my smoking problem.If the modulator valve is shot you will loose trans fluid into the inlet manifold,and it may cause spark plug foulling also (No.8 in my case)
Just replaced the vacuum modulator..so now it's on to the valve stem seals.
BTW, Changed my plugs yesterday, they were clean.
ATTENTION ANYONE WHO WORKS FOR HEDMAN, HOOKER or ... !!!!
*** Side note to guys who design headers... make them so we can get the plugs out without crawling UNDER the car. I should be able to use a normal spark plug socket on it also and not have to design special ways to get them out.....anything else is BS !
v/r
Jim
Lifetime Member #73
The Money Pit.... and my niece
(click to see a slightly larger version)