smaller 3/8" umbrella seals ?

[TomP]

I am putting  a pair of FE heads together and the springs are doubles... and won't fit the normal umbrella seals. Guides are too big for PC seals. Pretty sure i've heard of smaller 3/8" umbrella seals. Anyone know an applicaion or part number?

[pbf777]

Well, I don't have any dimensions of what you might really require but there is this:


GM UMBRELLA SEALS, 3/8"
Application: SB Chevy Truck Engines w/ 3/8" Stem exhaust valves

    Specification Data:

    Fits: 3/8" Valve Stems.
    Inside Diameter, smallest point: .605”
    Inside Diameter, widest point: .635"
    Outside Diameter: .715"
    Height: .450” Tall
    Seal Material: Poly Acrylic
    Material Temp Rating: 375F
   
AVAILABILITY: 

But I think, you might be barking up the wrong tree with this plan!   

    Scott.
   

[TomP]

Who'da thunk SBC's even had 3/8" valves! Thanks. I think those should be OK. Just two sets of them. Found a link with them and dimensions of others too. Some are larger PC seals.   https://www.alexsparts.com/valve-seals-3-8/

[TomP]

Actually these look ideal . late 80's 318 Mopar, PC seals with .640 ID   https://www.alexsparts.com/3-8-positive-in-ex-seals-viton-sb-chrysler-318-360-1988-1991-3-8-x-640-vss-275/

[manofmerc]

These pioneer #940 are probably to big but a really good seal for stock heads .I have used them on two engines and they work fine .I believe they came on buick v-6 engines .Good luck ! Doug

[pbf777]

  https://www.alexsparts.com/3-8-positive-in-ex-seals-viton-sb-chrysler-318-360-1988-1991-3-8-x-640-vss-275/

     I'm assuming you realize that these seals you have listed are not an umbrella seal as was your first inquiry, and what your saying is that the current guide boss O.D. is within the acceptable values provided in the specifications of .640 - .650"?   

     Scott.

[gt350hr]

   SBC Chevy/GM truck with sodium filled valves is the application.

[TomP]

Parts store seems quite useless at finding anything. Any idea what years or truck models had them? Last time I did this the seals were just something I had already.

[manofmerc]

Why not see if pioneer has a website?If you have a p.n. it would be easier than dealing with a parts store .That pioneer seal I mentioned I bought them from Jegs .I just gave them the p.n. and they sent me two sets .Or maybe an older machine shop would have some sitting around .Doug

[TomP]

Yeah those Pioneer ones seem to be quite scarce too, but i found a common application.... BB Chivverlay with dual valve spring, like L88's. Local store can get those, FelPro number SS72513