The Stovebolt Site Forums The Shop Area Engine Shop Valve Seal Question, 350 V8

Hi All,

I am going through some heads off a 350 that using new dual valve springs. I have a set of "umbrella" valve seals to use, but it seems like they are pretty tight inside the springs and may not last. Does anyone have any experience on this subject? The motor is going in my 63 K20 project.

Umbrella seals should not rub the inside of the springs at all, if they fit right. Also, if you use them, take the sheetmetal deflectors off the tops of the springs, and don't use the "O" ring in the groove under the split lock. Doubling up on the sealing like that will result in the guide getting almost no lubrication, and wearing out in a hurry.
Jerry

Edit: I just re-read your post and saw you're using double spings. The only thing that will work with them is the small teflon seal that grips the top of the guide, and those seals require machining the guide for a correct fit. Don't attempt to use the umbrella seals at all!
Jerry

How about the "O" ring in the groove under the split lock? If I should use them, I hope they come with the Felpro or Mr. Gasket gasket sets.

Nope, no need to use them, if you've got the machined guides and positive stem seals. Dual springs are only necessary if you're running above 7,000 RPM. Do you plan to run it that fast on a routine basis? If not, all you're accomplishing is a lot of camshaft wear, in a hurry!
Jerry

The new dual springs just came with the heads that I got from a drag racer. He said they were z-28 style. I'm not so sure about the positive stem seals as I don't see anything that resembles a seal on the top of the valve guides. Is it wise to remove the inner springs or just get new single springs?

Here's an excellent single spring kit, with retainers and keepers included, and the price is right. It's good for up to .510" cam lift, and 6,000+ RPM. I use it for street performance and roundtrack engines.

http://engnbldr.com/ChevroletHotLicks.htm

Scroll down the page until you get to the spring/retainer kits. The .600" lift set is only needed for extreme-lift cams, mostly for competition-only applications.
Jerry