Ok, my car had the infamous puff of smoke on start up before. Now Im putting those same heads back on the engine. But wanna get rid of the puff of smoke. It didnt burn any while driving, just on start up.

I popped a valve spring off tonight and took a look. Under the keeper there was a black O-Ring kinda thing in one of the grooves, it ended up breaking off, but when it was on it actually held the valve in the head too.

What are umbrella seals

Will it fix the puff of smoke

what was that black ring

how much can I expect to spend to get rid of the puff.

 

Good question. The only seals I am familier with are the valve stem seals, which is the o-ring you mentioned. I know there are valve guides, it makes sense there should be valve guide seals, which seem more logical a culprit of the "chevy puff". I actually don't know the purpose of those little o-ring valve stem seals, other than to insulate the locks to keep them from moving.

 

I just did mine. You have one of the o rings on each stem in the second groove. On the exhaust valves you should get umbrella seals for them. Go to any parts store and they will have them. The black seals are on the intake which i believe are called posiloc seals. No parts stores around here had them so I didnt replace them. I just put new o rings (most of mine were brittle and hard) and the umbrella seals. Factory my lo3 heads didnt have them but I installed them and it fixed the problem.

 

You can also get teflon seals that don't harden like the factory style. I would make sure valve guides aren't loose.

 

You mean Viton seals ?

 

do you need any special tools or anything to install umbrella seals?

 

No they just slide over the exhaust valve stem. Very straight forward.

 

Sweet! Then I should have my car back soon

unfortunetally it wont be a 383, it will only be a 350, everyone had been screwing me and my 383 would have taken a lot more money and time that I have run out.

 

Nope teflon there are two different styles one that is all teflon and one with teflon inserts in rubber that look more like the stock seals.

 

hey 86...... i feel i need to put my .02$ in here...

as mentioned above there are 2 types of seals..... a positive type or "viton" which had two small springs that surrond the top and bottom of the seal, and the regular umbrella type...

if you use the regular umbrlla type you take a very small chance in ending up with the same problem that you had before....

with the seal not scraping the valve to remove enough oil from the valve stem which results in a small oil leak that will create small deposits on the back of the intake valve.....

the reason viton or positive type seal are better all around is because the two small springs keep tension on the valve to remove the oil better..... you don't have to worry as much on the exhaust valve because the pressure of the exhaust keeps the oil out of the guide....

if you want the new ones that came in my kit send me your address and there yours... i don't need em because i bought assembled heads for mine......

i hope that i helped, keep us posted on the ta dude!!!

 

are they these that I posted about?

https://www.thirdgen.org/techbb2/sho...hreadid=134339

If so, could I put them on the exhaust & Intake valves, just to be sure.

they just slide on and end up inside the spring rite?

 

those are the good ones.... the others are like hollow and just suck unless they are used in exhaust only......

if you noticed the metal ring on it, it's used to do what the spring does on simular ones.... it just keeps a tight clamp on the valve for better oil control........

well good luck and if ya need anything else ya know where im at....

 

GM addresses the issue with a TSB. Corporate Bulletin #136007 recommends kit #12511890 for correction of problem. The kit incorporates a "viton" insert and uses a positive type seal. It's available from GMSPO for about 40-50 bucks for all parts to do the entire engine.

 

The umbrella type does not scrape the valve stem, or anything else. Its hole is small enough that it latches itself onto the stem and rides up and down with the valve, and just mostly covers the top of the guide from oil getting splashed there. Only slightly more effective than the O-ring on the intake side where there's vacuum on the other end of the guide, but plenty for the exhaust side.

You have to get your guides cut to a precise diameter, either .500" or .530" depending on which part # you use, to use the all-Teflon seals.

I guess it's about time GM figured out there is a problem with what they are using, and was kind enough to issue a TSB for it... the rest of the world has known about that for about 45 years now and has long since figured out how to re-engineer what GM screwed up... Fel-Pro for instance has been supplying positive seals for stock-diameter SBC valve guides since before most of the TSB issuers at GM were probably born. And their "kit" costs a fraction of what GM's does, about $18 IIRC for a set.

 

so can I use the ones pictured in the other post on intake and exhaust?


thanx everyone for your help.

 

Yes. They should definitely go on the intake, exhaust is not as critical.

 

is this how they go on? may sound dumb, but a friend of mine told me they go on the valve, flipped over, and then the guy at the speed shop told me they go on like I have in the pic, but the head has to be cut for them. The seemed to go on as they are now perfectly fine.

 

That doesn't look right...

They should fit over the top of the guide and cover it, and fit tightly to the valve stem.

 

Ok I drew a picture to show how it is, my digi cam pic sucks

in the pic the grey part is the guide, how it is skinnier at the top, obviously the valve in down the center of the guide, and the red part is the seal. if I move the valve up and down, the seal stays in place, but your rite, it doesnt look rite. But I did install it the way the instructions say.

heres them quoted:

"POSITIVE SEAL GUIDE:

Use the plastic installation sleeve(s), included in this set, to preven damage to the lip of the seal. Trim the plastic sleeve so it extends 1/16" below the keeper groove. Place the sleeve on the stem.

Carefully start valve stem seal over sleeves. Remove plastic installation sleeve and reuse for installing remaining seals.

FOR RUBBER JACKET SEALS: Push seal down over valve guide untill it bottoms."

then it goes on about Solid of metal jacket seals, which I dont have. and then about re-installing the springs.</p>

 

I have one on like that, and also the O ring seal that come with them, and the spring and retainers put back in, hope we decide it'll work like that so I dont have to take it apart again.

 

Should I just do the exhaust to while Im at it.

 

*Bump*

 

Absolutely, do them all one way or another...

One thing they fail to mention in that blurb is that while there may be vacuum some of the time at the exhaust guide, there's pressure most of the time. And if the guide is bad, that means exhaust gas leaks up from the port to the seal. And seals don't last real long with 1200° gas on them. So with a used motor with worn guides, the positive seals may not survive long in that location. The umbrellas may be a better choice on the exhaust side: they block probably 80% or more as much of the oil as positive seals would, but won't get destroyed by the heat.

This is why I always have my guides machined down, and use Teflon seals, in any motor I really care about.