[Grant209]

i have 77 4 barrel chevy 350 that came out of a truck and im going to do a valve train change cam, lifters, valve springs ect.... and i was thinking since ill have the valve springs off i should put new valve seals on too....Well my question is what type are the best seal to use?
Thanks
Grant

[1981monte]

Umbrella seals, not "o" ring

[BOBCRMAN@aol.com]

The best seals to use on a street engine are the positive oil controll sals that are used on the 87 and later small blocks on the intakes and an umbrella seal on the exhaust. They work great.

[383strockerfanatic]

I agree with bobcrman that how iI run all of mine. But Im not the best to ask lol

[machine shop tom]

Depends on the cam you pick. Any more lift than .420" and you will have interference between the retainers and seals.

[jimfulco]

What about the rubber/teflon ones seen on page 4 of:

http://www.hi-performance.com/catalo.../PG071-074.pdf

[Grant209]

Ok im going to be running a 454" lift crane engergizer cam with matching valve springs and retainers....i appreciate all feedback
Thanks
Grant

[brainsboy]

I like the Viton rubber seals. Viton seals will not harden or crack like the teflon seals. They also have a higher heat range. They are a positive oil seal. These would be a good choice for your intake valves. when I rebuilt my ferrari motor, which are famous for burning oil due to teflon seals that crack, I lathed new valve guids to use a BMW 8mm viton seal on both intake and exhaust. If you want to PM me, I can give you a phone number to order wholesale Valve seals. Im sure they have both viton or teflon seals for your application.

Ben

[Grant209]

So my final question is could i use the positive type valve seals with my application?
Once again all feedback is much appreciated....
Thanks
Grant

[machine shop tom]

Originally posted by Grant209
So my final question is could i use the positive type valve seals with my application?
Once again all feedback is much appreciated....
Thanks
Grant

Yes, you can and should use positive seals. BUT, the heads have to be set up for the cam you are using by machining the guides for the seals and proper seal-to retainer clearance.

[Grant209]

Thanks alot for the help....I really am not trying to pull the heads off the motor to have them machined so i will probly end up using the umbrella type seals.....But thanks its good to know that type of info because i probly would have just went out and bought the positive type seals and installed them and then i would have ran into some problems....
Thanks
Grant

[machine shop tom]

Make sure to install the o-ring seals as well cause you'll need something to provide sealing when the retainer chews up the umbrella seals due to interference!

[Grant209]

So is there a better setup to go with without machining the heads? Or am i running into trouble any way i look at it without having the heads machined?
Thanks
Grant

[machine shop tom]

nope. yep.

[Grant209]

Thanks for all your information and help....I will probly end up pulling the heads off and send them to the shop....Could you guess and tell me about how much it would cost to have a shop perform this type of work?
Thanks
Grant