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#1
03-08-2014, 02:15 PM
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valve stem seals?
6 x 4 heads with stainless valves. I was getting oil smoke out the exhaust. The intake side has Viton seals. The exhaust had o rings that were just slid down on the valve stems. Should the o rings be in the groove near the end of the valve, or would that prevent the installation of the keepers? I replaced the o rings with rubber boots that fit over the valve guides. One of them has come off twice. I'm guessing that I made a mistake by dipping them in oil before installing them. Should some type of sealer be used with the rubber boot type seals?
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#2
03-08-2014, 04:14 PM
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The exhaust guides weren't cut for Viton seals?
__________________
 frittering and wasting the hours in an off hand way.... 1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core. 
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#3
03-08-2014, 10:42 PM
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O-ring type seal fits in groove below other groove for keepers. Rubber boot style seals don't stay down over valve guide. When valve opens valve seal will ride up valve stem the amount of valve lift and stay there.
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#4
03-09-2014, 08:03 AM
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Alot of SS valves do not have the needed second groove for the factory O ring.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#5
03-09-2014, 09:31 AM
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You also must use factory retainers and factory oil shields for the "O" ring valve seals to work correctly. The correct order of assembly is also a must. The retainers and springs are compressed FIRST, then the "O" rings are pushed onto the lower grooves on the valve stems, then the keeps, then the spring compressor released so the retainer moves up and seals off at the "O" ring. Any other attempt at that deal and they will get pushed down off the grooves and leak.
That technology is pretty effective at oil control, but not nearly as good as the new positive type seals with the metal shells, bonded material and springs to wipe the valve stems. I haven't used the factory "O" ring set-ups in at least 15 years, and to date haven't had the first issue with the positive type seals. It is the very best way to set up these heads, IMHO.....Cliff
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#6
03-09-2014, 09:46 AM
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My valves only have one groove, so I guess the o rings are out.
The positive type seals I have will not fit over the valve guides on the exhaust side. Do they make larger ones, or am I stuck using the rubber boots? |
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#7
03-09-2014, 10:04 AM
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At least you have discovered the oil control issue. I'm not a big fan of any sort of umbrella seal on Pontiac heads, as the double spring set-up doesn't leave much room for them. Not sure if anyone makes a PC seal that fits stock guides and is still effective in long term service? The stock guides need to be cut for the good seals, which means the heads have to come off. Pretty sure my cutter is .530", but they make the seals and cutters in several diameters.....Cliff
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#8
03-09-2014, 11:55 AM
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Thanks guys. Cliff, you pretty much confirmed what I suspected but didn't want to hear. Because of the AC, pulling the heads means pulling the engine. This engine was rebuilt by a local Pontiac "Guru". All he had on the exhaust valves was an o ring even though there was not a groove for them. I later put the umbrella seals on. So far, they have all stayed on except one. I think I will try to prolong the inevitable by replacing the seal that came off. When the heads do have to come off, they are definitely going to a different builder.
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#9
03-09-2014, 03:45 PM
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Your "guru" is pretty much a twit if he installed the oil control rings riding up and down the valve stems loose like that. That is a high school kid's " I have these gaskets and it says they are valve stem seals so I'll put them on the valve stems" type of build. They were intended to be installed in a groove on the valve stem between the retainer and the keepers to prevent the oil that puddles around the valve stem on the retainers from running down the valve. A plastic sleeve for install is typically included with the O rings that is placed over the valve stem tip to allow the O rings to be slid down to the bottom groove without getting knicked by the keeper grooves. As installed, yours did nothing for oil control.
Aftermarket valves almost universally have no O-ring groove since it is assumed aftermarket retainers and positive oil seals will be used and the stock oil shields will be discarded. I like the .530" diam Viton seals on both the intake and exhaust but you do have to cut down the guides as Cliff said. These are more forgiving than the rigid teflon seals and compensate for some valve stem wobble from valve guide wear as it occurs and maintains oil control longer. Last edited by NeighborsComplaint; 03-09-2014 at 03:55 PM. |
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#10
03-10-2014, 09:08 PM
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Update
I checked the seals on the valves with the originally oil fouled spark plug. Both seemed to be in place, but the umbrella seal on the exhaust side didn't go all the way to the head. I replaced it with a longer seal that sealed against the head. Before that, when I hooked the air hose to the spark plug opening, I got air coming out of the carb for about 15 seconds and then it stopped. Is that normal if one of the intake valves was partially open? After I replaced the seal, I still had a little bit of smoke coming out of the exhaust, but not nearly as much as before. I still have a spark miss. I replaced all the spark plugs on the passenger side where I was having the problems. I will check the plugs on the drivers side, make sure I got the firing order right, and re-check the timing. Is there anything else I need to look for?
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#11
03-10-2014, 09:25 PM
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What brand of plugs are you using???
The trick plug of the month can cause problems. AC, Autolite or even Champion plugs are the way to go, none of their fancy models, either. I'd remove all the other plugs, and give them a look, just to be sure... The next time you have a spring off, can you measure (w/ a dial caliper) the valve guide boss. There might be a proper seal that sill fit the guide boss (maybe...maybe not) without machining...
__________________
1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... 
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#12
03-11-2014, 01:05 AM
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Quote:
Any time I have had a steady miss, it has been a plug wire or a cracked insulator on a plug. Be careful that the umbrella seal isn't too tall or the retainer will squash it against the guide. |
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#13
03-11-2014, 07:04 PM
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I'm stumped
As a recap, I checked the valve seals on the passenger side that had oil on the plugs and smoke coming out the exhaust. They looked OK, but I replaced the plugs and one of the exhaust valve seals. When I fired it up last night, I had a little bit of smoke coming out the passenger side but still had somewhat of a misfire. Tonight I checked the firing order (new wires) and it was ok. When I started the engine I got quite a bit of smoke out of the passenger side again. I pulled the plugs out of the drivers side and the last one looked very oil fouled. I was getting very little smoke out of the drivers side. Is it possible that oil from the drivers side was traveling to the passenger side? I have the heat crossover blocked off, but can the oil go through the intake to the other side?
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#14
03-11-2014, 07:06 PM
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OIL TRAVEL
If the PVC is sucking oil it can go to all cylinders.
__________________
1968 Firebird 400, 068 cam, TH400 & 13" Continental Converter, Auburn posi with 3:08 factory gears, Cliff's Q-jet resting on a 68 factory iron intake, DUI HEI and Ram Air pans and RARE Long Branch Manifolds |
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#15
03-11-2014, 08:42 PM
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When I had my #96 heads at the machine shop I was talking to them about basicly the same issue. I had black caked up spark plugs and was blowing some blue smoke on startup and some times at full throttle.
My machine shop told me that those rubber umbrella sheild are horrible and from what he had seen end up pumping oil into the valve stem rather then control it. I had them put the viton seals on with new valves and guides and the issue is now gone. |
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