Valve stem seals

[dgoodhue]

I found this thread on replacement GM Valve seals, but is their a better more durable aftermarket alternative? I am using the stock heads and valves.

http://www.syty.net/phpBB2/viewtopic...190&highlight=

[Falco]

I've also used the stock seals, but a bunch of people recommend to use viton seals. Search for viton here and you will find a few threads...

HTH,

[sytyguy]

This might help ya find some locally.

Intake Valve Stem Seals
- Felpro - SS72529
- Victor - B45418

Exhaust Valve Stem Seals
- Felpro - SS72876
- Victor - B45779

Victor is sold by the each (but usually stocked in bags of 4), and Felpro comes in a box of 8.

HTHs

Michael

[dgoodhue]

Originally Posted by sytyguy

Intake Valve Stem Seals
- Felpro - SS72529
- Victor - B45418

Exhaust Valve Stem Seals
- Felpro - SS72876
- Victor - B45779

I tried doing a serach on these and didn't find any info on these by either the manufacturers, summitt or jegs. Autozone came up with the exhuast number but the intake number was incremented by one number, SS72530

From my seacrhing/reading, a positive seal is more desirable. Is that what the above is? Is their a replacement part that I can order from summitt or jegs. BTW What size is our valve stem 5/16,11/32,...? That would proably help me out in narrowing down my search.

[TyMeUp]

Fel-Pro Catalog listing for 1993 GMC Typhoon 4.3L V-6 TBI Turbo (Z):

Fel-Pro #SS72876
Contains Prem. Quality Valve Stem Seals; Exh.; Opt. Hi. Temp. ($9.89)
Fel-Pro #SS72529
Contains Prem. Quality Valve Stem Seals ($19.22)

Note: Set Part Number SS72529 Includes:
Component - - Quantity
Valve Stem Seal Nitrile - - 12
Installation Aid (sleeve) - - 1
Valve Stem Seal - Blue Viton - - 6
Valve Stem Seal - Nylon - - 6

The #SS72530 would be correct for the intake valve seals, but is listed for a V-8. You would get eight seals intead of six. If your local AutoZone handles Fel-Pro, they should be able to get the #SS72529 complete set.

Fel-Pro is preferred over Victor in my shop because they include complete installation instructions with all their gasket and seal kits. The valve stem seal sets also include an installation aid (a sleeve) that fits over the end of the valve stem. It protects the seal from damage by the sharp edges of the lock grooves.

http://www.federal-mogul.com/cda/con...6_7501,00.html

BTW Dave: The above parts are 'positive seals'. The OEM Chevrolet 'O-Ring' valve stem seal design has been used since 1955. It works by sealing the valve spring retainer to the valve stem, preventing oil from running through the split locks, down the stem and into the valve guide. When used with the upside-down cup shaped 'oil shedder' on top the valve spring, it turns the top of the valve spring assembly into a large 'umbrella' seal. This sealing system works well until 75,000 miles or so. At that point valve stem-guide wear and increased blow-by pressure begins to overwhelm this 'non-positive' sealing system.

[Hu Ryde]

See the Blue? Viton.

[4C FED]

I'm confused now.
I just came back from Autozone and they had SS72529, but it was missing the installation sleeve so I passed on it.

Anyway, I thought that we wanted to use the viton on all of the guides.
In this kit, the viton is used for intakes and the nylon (umbrella type) is used for the exhaust.

Are the nylon seals any good for the exhaust or should we use all viton?

[TyMeUp]

In addition to the installation sleeve, the kit should also include 12 OEM type O-ring seals. Did it? My guess is that you were shown a 'returned' package. Fel-Pro is a well known brand, so I would check at another parts store.

I beleive the Nylon would be recommended because of the higher exhaust valve temperatures (especially on the turbo engine). The Viton was shown rated for 440 degrees, but the exhaust valve stems may get somewhat hotter than that.

Anyway, I'll get back into my Fel-Pro catalog tomorrow and see what else may be listed for the 4.3L (and for the Chev V-8s). Back when Fel-Pro was not part of a huge conglomerate, they had a product info hotline where you could call for specific recommendations for gasketing problems. I'm wondering if they still have that?

[4C FED]

Yep, it had those silly little o-rings in there.

I asked them to get set from another store. They should be in tomorrow.

Thanks

[TyMeUp]

The final word on valve stem seals... I hope.

First, a correction. The SS72530 number is correct for the 4.3L V-6 Intake seals. The corresponding 5.7L V-8 number is SS72527. That's what I get for taking notes while talking on a phone in a noisy shop.

This time I requested a copy of the latest Fel-Pro catalog from my parts supplier. My old catalog was a few years old. The new catalog held a surprise. The #SS72529 set is no longer listed for the 4.3L Turbo V-6. It is listed only for the 1985-86 4.3L engines. This is the current listing:

4.3L 262 OHV TURBO V6 (CHEVROLET), 4" BORE - 1991-93 - L/D TRUCK VIN CODE "Z" 1991-93

VALVE STEM SEAL SET - YEARS - PART NO. -- DESCRIPTION
Valve Stem Seal Set -- 93-91 -- SS72876 --- Exh,; Premium valve stem
seals incl.
Valve Stem Seal Set -- 93-91 -- SS72530 --- Int.; Premium valve stem
seals incl.

To get an accurate description of these seal sets, I called the Fel-Pro Tech Line (1-800-325-8886) as listed in the new catalog. The tech that I spoke with described the #SS72530 set as Viton 'positive' seals and the #SS72876 as Nylon 'umbrella' seals.

When I asked why Fel-Pro went with the umbrella style instead of the positive type, the answer was that their engineers determined that this seal would hold up better and that the exhaust seals didn't have to work as hard as intake seals (not as much vacuum on the exhaust side).

Next, I asked if he could recommend a 'positive' seal for the exhaust stems. After checking his listings, he came back with #SS72711. This set was described as eight Viton 'positive' seals.

Finally, I asked if I should use the stock O-Ring seals along with the new positive seals. The answer: "There is no reason why you shouldn't…they can only help control the oil flow to the new seals, making their job easier."

I never did find out why the #SS72529 seal set was relisted for only the earlier heads (1985-86). My older calalog shows its application as 1985 - 1995. Are those ealier heads that different?

[4C FED]

Thanks for all of the info.

Looking at the Comp Cams catalog, it looks like they have a "red" viton seal for the exhaust.
I might have to buy some of those to check them out.