I'm going to replace my valve seals. Should I just go to my GM dealer and get them there? Or are there better ones to use? Who has had good luck with what brand? And the parts stores where you got your seals would be appreciated.

 

Hey man, I just did this not too long ago. Just go down to NAPA and ask for 16 of the positive locking ones (they are the stock ones for the intake side) and 16 valve stem o-rings. The way to tell if they give you the right ones is look at the seal and it will have a metal ring clip on it. I put those in my 350, and havent had even a puff of smoke since. The only part that sucked was getting off mt right side valve cover, and getting the comp gauge hose into #5 (that took almost 40 minutes). Aside from the #5 problem, I had them done in about 2 hours including re-assembly and getting my car off the jacks (about 2.5 hours total).

 

Do you know what brand you got? Were they the Fel-pro Viton Positive Seals? Did you use the same seals on the exhaust and the intake? And I have heard that when you use a positive type seal the head has to be machined, is this True? And what kind of valve spring compressor tool did you use? Thanks

 

They were the Napa brand. I used the ones listed for the intake on the intake, and the optional exhaust ones on the exhaust(they both fit exactly the same on each, but I kept the intake on the intake & the exhaust on the exhaust). There is a positive locking one for the exhaust available and the guy you deal with should be able to get you the right ones. I didn't need to do any machining on my valve guide to make them fit, just slipped the old umbrella (shedder style, don't get those) seals off and slipped the new ones on. I wish I could tell you moe detailed info, but I delt with a good friend of mine, the "Parts Masta' Supremeo". When you tell them that you need valve guide seals, and they look them up, it will list positive retention style for the intake, and shedder type for the exhaust as stock. Tell them yours has the posi-lockers on both and they will hook you up. Before you leave make sure that you have the following parts accounted for. 16 positive locking seals (there will be 2 boxes of 8 and you may have to buy the umbrella seals with the intake seals, just ****can them), 16 valve stem o-rings, and new valve cover gaskets (rubber ones).
As for the spring compressor I used, I have a Snap-On lever type that hooks under the rocker nut and presses down the valve stem. it worked slick as hell on all of the valves. Do you know how to keep your valve from falling down into the cylinder while you have the retainers off? if not send me a PM and I'll give you a step by step.

 

I'll second that...

 

That's it exactly. The intake & exhaust ones are actually made out of different materials, the intake ones seal better but the exhaust ones stand up to the heat better. Over time an intake one installed on an exhaust valve will deteriorate faster than the correct one would.

Personally, I don't bother with the O-rings that go inside the retainer under the keepers; the thing you're putting on is so much better, it doesn't matter if those other things are there or not. Same for the umbrellas; they're better than O-rings but still only about 5% as effective as the positive seals with the metal band.

The ones you have to get the guides cut for are the Teflon ones. Purists like me always do that when working up a set of high-perf heads as part of cutting the spring pockets for decent springs, but if you're using low-perf (stock diameter) springs anyway, just use the stock size seals.

The lever type spring compressor is by far the best way to do them with the head on the motor.

Rather than air, you can use a piece of ¼" nylon rope, put the cyl at firing, and just stuff it in until the cyl is full. Much easier and better than air, which tends to push the piston back to BDC.

 

Fel Pro part number:

Intake valve stem seal set (positive seal):
SS 72527
approx $12/set

Exhaust valve stem seal set (not positive seal):
SS 72877
approx $17/set

that's all I've got right now on it.

GTA, You say there is a positive seal for the exhaust side? Can you add part numbers for that for me?

RB, is your 5% on umbrellas with respect to positive seals for real? I knew the difference was substantial, but didn't realize it was that big!

MikeS

 

Hey MikeS,
How do those Felpros work? Did they stop the smoke at startup? That is if yours did smoke. I was thinking of buying Felpros but these guys have me talked into all postives from napa.

 

Funny you ask. I'll let you know as soon as I get them put on ! They're still sitting here on my desk right now. I'd rather be putting a positive type seal on both the intake and exhaust side, but I think I'm going to go with what I've got since it's already here and paid for. Oh, and yes, mine does smoke at startup right now. Nothing major, but it annoys me and I don't really have much to do lately. So, depending on if the rain lets up, I should have them done in the next few days.

 

NAPA doesn't make them, they re-box somebody's. Most of the time they do a good job of picking at least decent stuff, even if not always the best possible stuff out there.

I'd use Fel-Pro myself, but if it wasn't available, I would consider NAPA an acceptable substitute. Either one is far better than what you've got.

5% is just an estimate.... I suppose it depends on teh condition of your guides.... but I can easily see an umbrella letting 20 times as much oil past it as a positive seal would.

 

Looks like I am going to have to go with the Felpro positive on the intake and the umbrella on the exhaust. There isn't a Napa here in Wichita. I could order off there website but I would rather get them here in town. Do you guys think the Felpros will stop my smoke at start up? Even with an umbrella on the exhaust? Anybody who has this combo? If you think I would be better off with all postives can you take a look at the napa website and see if i have the part numbers right: intake: CEP2161143 and exhaust: CEP2161067
These look like the right ones to me but just want to make sure.

 

hey guys i went to my local napa the other day and they didn't carry the positive locking seals and also went on to say that they couldn't get them. Could someone check the p/n's on their website above and state which ones are the posilock ones?

 

Victor supplies NAPA with seals and gaskets. Any one of your local parts stores should have the positive style seals your looking for.

 

Like RB says, have your heads machined for teflon seals. It was preety cheap to have it done as I recall.

 

i woudl have my heads machined but I'm saving that money for the 350 build up. Not really in the mood to spend all that cash on the 305, but I would like to just do the valve seals to get rid of that ugly smoke. I've gone to 3 parts stores and none of them carry the positive locking seals. Guess i'll give a few more a call

 

Visit NAPOnline or sdpc2000.com or paceparts.com

 

i did go to the napa website, but it has a number of different valve seals, I wasn't entirely sure on which ones were the posilock ones. somebody in a few posts above posted some p/n asking teh same question i have, but it was never answered. thats why i dug up this old post to find out if those part numbers are correct.