The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Are regular valve seals and umbrella seals interchangeable?

GRX · 05-29-2012, 02:03 PM

I am a machinist and am very familiar with this. Being the '67-'72 section ... the stock seals on your 350 are O rings which fit inside the spring retainer. That in conjunction with the sheet metal oil shredder on top of the spring act as an umbrella. You can take the retainers off as you suggested and install rubber umbrellas inside the springs. Now that is IF your valve guides have been machined to accept them. Otherwise you will have to remove the heads & pay a machinist to cut the outside diameter down. Cost and your budget depending of course. Then there are positive locking seals which fit tightly on the valve guide and do not ride up & down with the valve like the umbrella does.

Here is a pic. A= Positive locking, B and C = umbrella (soft & hard), and then an O ring which fit into a groove on the valve stem and inside the retainer cap.

05-29-2012, 02:03 PM	#4
GRX Registered User Join Date: Jul 2010 Location: MD Posts: 1,937	Re: Are regular valve seals and umbrella seals interchangeable? I am a machinist and am very familiar with this. Being the '67-'72 section ... the stock seals on your 350 are O rings which fit inside the spring retainer. That in conjunction with the sheet metal oil shredder on top of the spring act as an umbrella. You can take the retainers off as you suggested and install rubber umbrellas inside the springs. Now that is IF your valve guides have been machined to accept them. Otherwise you will have to remove the heads & pay a machinist to cut the outside diameter down. Cost and your budget depending of course. Then there are positive locking seals which fit tightly on the valve guide and do not ride up & down with the valve like the umbrella does. Here is a pic. A= Positive locking, B and C = umbrella (soft & hard), and then an O ring which fit into a groove on the valve stem and inside the retainer cap. __________________ 1969 c-10 Step Side Long Bed. I-6 250cid = = 1969 Pontiac GTO hard top. 400, 4-speed. Last edited by GRX; 05-29-2012 at 02:09 PM.