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Topic Review (Newest First)
12-12-2012 05:23 PM
cobalt327 Me too. Mainly because when the truck's done he's got some better iron for us to play with!
12-12-2012 04:28 AM
123pugsy Hey Moe.

X2 on the lube.

Glad to see you're back on the truck.
12-11-2012 09:41 PM
cobalt327
Quote:
Originally Posted by lt1silverhawk View Post
Finally gonna do the valve stem seals. Would it be ok if I applied a little motor oil to each seal before slipping it on? A little oil underneath won't hurt anything I assume.

Thanks,
Hey guy! Yeah, a dab of lube is a very good idea, dry start up can ruin a seal in short order. I wouldn't bother with putting anything under the seal necessarily, what you want is the seal ID where it rides on the stem to have some lubrication. Motor oil is fine if you're going to run the engine soon, if it's going to sit you can use a smear of lubriplate on the stems- that will stay put.
12-11-2012 09:37 PM
lt1silverhawk
Quote:
Originally Posted by cobalt327 View Post
Sometimes air gets trapped under the seal and (kind of like when you use silicone grease on spark plug boots) the seal wants to pop back up unless the pressure is relieved. Might take a little pinch/squeeze at the top of the seal to distort the ID of the seal just enough to let air out past the valve stem. Or maybe use a toothpick to slip in between the stem and seal.
Finally gonna do the valve stem seals. Would it be ok if I applied a little motor oil to each seal before slipping it on? A little oil underneath won't hurt anything I assume.

Thanks,
07-16-2012 06:49 PM
lt1silverhawk
Quote:
Originally Posted by cobalt327 View Post
I hear ya on the exhausts. If you're keeping the seals anyway I suppose you could hedge your bet and use the "loose" seals on the exhausts and the tight ones on the intakes...
Yeah, I was thinking the same thing, 'till I tried the Fel-pro SS 72527 on the intake valves. They seemed like a tighter fit than the ones' from Alex's Parts. When I do cylinder #6, I'll try them on the exhaust first to see if there is a difference. Now the Fel-pro SS7287 might be a better bet. I'll give them a close look.
07-16-2012 06:13 PM
cobalt327
Quote:
Originally Posted by lt1silverhawk View Post
LOL! I tried the pinch/squeeze method but that was a bit difficult with the metal bands around these viton seals. Then again, I'm always so paranoid about damaging anything, I probably didn't apply enough pressure. The tooth pick I would've never though of, since I'm having to use an installation sleeve to protect the seals.


I gotta say, these seals are really tight and it does take some serious pressure to slide 'em down. But once they are, I can tell there aren't going anywhere. I almost became concerned that the exhaust valves may not get enough lubrication.


Thanks cobalt!
I hear ya on the exhausts. If you're keeping the seals anyway I suppose you could hedge your bet and use the "loose" seals on the exhausts and the tight ones on the intakes...
07-16-2012 01:47 PM
lt1silverhawk
Quote:
Originally Posted by cobalt327 View Post
Sometimes air gets trapped under the seal and (kind of like when you use silicone grease on spark plug boots) the seal wants to pop back up unless the pressure is relieved. Might take a little pinch/squeeze at the top of the seal to distort the ID of the seal just enough to let air out past the valve stem. Or maybe use a toothpick to slip in between the stem and seal.
LOL! I tried the pinch/squeeze method but that was a bit difficult with the metal bands around these viton seals. Then again, I'm always so paranoid about damaging anything, I probably didn't apply enough pressure. The tooth pick I would've never though of, since I'm having to use an installation sleeve to protect the seals.


I gotta say, these seals are really tight and it does take some serious pressure to slide 'em down. But once they are, I can tell there aren't going anywhere. I almost became concerned that the exhaust valves may not get enough lubrication.


Thanks cobalt!
07-16-2012 01:33 PM
cobalt327 Sometimes air gets trapped under the seal and (kind of like when you use silicone grease on spark plug boots) the seal wants to pop back up unless the pressure is relieved. Might take a little pinch/squeeze at the top of the seal to distort the ID of the seal just enough to let air out past the valve stem. Or maybe use a toothpick to slip in between the stem and seal.
07-16-2012 12:56 PM
lt1silverhawk Hi All,


Just doing a quick check-in and update on the valve stem seals. The viton seals Alex's Parts came in middle around Thursday. They look quite similar to the Fel-pro blue positive stop seals but had a smaller inner diameter (approximately 0.314" vs 0.334). All the new seals can be seen below for comparison.







I first tackled the seals on cylinder #2. I used some scotch tape on the valve stems to protect the seals. Its a bit tricky to make that work because of the oil on seals. But I quickly discovered that, due to the tight inner diameter of the viton seals, the scotch tape was getting stick inside the seal and almost impossible to remove by hand. A gently pull with pliers did the trick.







After I installed the exhaust seal, I tried to install the intake seal but it was the diameter seemed to small for the guide boss. So I moved on to cylinder #4 to see if I would have the same problem and I did. The scotch tape would get stuck inside the seal and it wouldn't seat all the way. So I decided to take a gamble and try the blue Fel-pro seal and, surprisingly, it was even worse. Having already used a seal from the Fel-pro box, I went ahead used the included installation sleeve and it worked like magic. The seals fit flawlessly. I'm gonna have to contact Alex's Parts and recommend they include the installation sleeve with the set.






So, only two cylinders got done. Will get the rest finished this coming weekend.
07-09-2012 03:06 PM
lt1silverhawk
Quote:
Originally Posted by cobalt327 View Post
Go ahead and use the second set, no need to buy two sets.
Thanks, I ordered them a little while ago. Hopefully they'll show up this week and I'll install 'em this weekend.




On a related subject, I was looking up information on rebuilding cylinder heads and came across ac article that mentions PC and Viton seals. Not thing major but thought it was an interesting tid bit.


Quote:
"Valve-guide seals are another important consideration. While O.E.M. seals do an adequate job, JGM prefers to use Viton rubber seals available through a number of sources including Fel-Pro. These seals are positive seals, meaning that the valve guide must be machined to allow the seals to fit properly over the guide. For more information on Viton seals, refer to “Oil Control” in the October ’93 issue of Hot Rod."


"Hot Rod Magazine: Heads Up! Rebuilding Cylinder Heads The Right Way": Image 14


Read more: Cylinder Head Rebuild - How To - Hot Rod Magazine
07-09-2012 09:35 AM
cobalt327
Quote:
Originally Posted by lt1silverhawk View Post
Hey cobalt,

I wanted to run something by. You mentioned that the picture of the valve I posted in post #136 has double grooves.
Maybe I picked up on the double grooves from the linked-to video? Yours are not double.

There's no choice when it comes to the seal ID, you'll use seals for a 11/32" stem and the wear will be compensated for by the seal having a smaller ID than the valve stem. Go ahead and use the second set, no need to buy two sets.
07-09-2012 09:08 AM
lt1silverhawk Hey cobalt,
Quote:
Originally Posted by cobalt327 View Post
That is a positive type seal, although the valve stems are set up w/the same double grooves (one for the keepers, the other lower groove for the small O-ring type seal) and there is a tin oil deflector, like has has been used since day one, pretty much.
I wanted to run something by. You mentioned that the picture of the valve I posted in post #136 has double grooves. I've taken a look a few times at the images I have as well as the valve stems themselves, but I am only seeing one groove for the keepers, much like the one shown on the right in this image (second one) from another forum by one of our members here: "2 groove valves: post #5. There is another view of both the intake and the exhaust stems in post #139.




Quote:
Originally Posted by cobalt327 View Post
The second ones have a more positive sealing area, and might be the better choice for used valve stems. But there can be too much sealing; you want there to be a slight amount of lubrication reaching the valve stem/guides. But in the case of a SBC, the guide is the head itself (cast iron) so there is always "extra" clearance.

Bottom line is I'd expect either to work. The second ones would be a good intake seal, the first ones possibly a better exhaust seal (where you need a bit more lubrication reaching them). If you were only going to get one set, the first ones in conjunction w/the small O-rings, or the second ones w/o O-rings.
Great! I'll consider ordering both sets. Otherwise I'll do the second set by itself. The reason I am concerned about getting the right set is because I've never replaced these before and do want to eliminate the plug-fouling issues. I definitely follow on the too much sealing, but I am not sure on how " reasonably loose" can a seal be. I imagine using a seal meant for a 0.344" valve stem is ok on a 0.341" valve stem. Any advice on this is greatly appreciated.




Hey Pugsy,
Quote:
Originally Posted by 123pugsy View Post
Hey Hawk.

You probably read it somewhere but I thought I'd throw it out there in case you haven't.

If you don't have an installation sleeve, use scotch tape around the keeper grooves to avoid cutting the seals.
Actually, one of the sets I bought from Felpro did come with a plastic sleeve. I won't be using that kit at this point, but had not come across the scotch tape method. Thanks!




Thanks!
07-09-2012 04:21 AM
123pugsy Hey Hawk.

You probably read it somewhere but I thought I'd throw it out there in case you haven't.

If you don't have an installation sleeve, use scotch tape around the keeper grooves to avoid cutting the seals.
07-08-2012 10:59 PM
cobalt327 The second ones have a more positive sealing area, and might be the better choice for used valve stems. But there can be too much sealing; you want there to be a slight amount of lubrication reaching the valve stem/guides. But in the case of a SBC, the guide is the head itself (cast iron) so there is always "extra" clearance.

Bottom line is I'd expect either to work. The second ones would be a good intake seal, the first ones possibly a better exhaust seal (where you need a bit more lubrication reaching them). If you were only going to get one set, the first ones in conjunction w/the small O-rings, or the second ones w/o O-rings.
07-08-2012 05:45 PM
lt1silverhawk So I measured and remeasured the valve stems as well as the boss guides for cylinder #2.


Intake valve stem: 0.3415"

Intake boss guide: 0.560"


Exhaust valve stem: 0.3415"

Exhaust boss guide: 0.559"




I measured the ID in the Felpros using a caliper, but they seemed a little smaller than the ones removed. I wanted to stop by a Chevy dealership's parts department to see what they've got, but they were all closed today. However, I did find these viton seals on eBay:

- Metal Clad Viton Valve Stem Seals 11/32" x .562" sb Chevy Ford Chrysler sbc | eBay

- VITON VALVE SEALS 11/32 SBC SBF GT40P PONTIAC .520-.565 | eBay
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