Valve seals for exhaust

belsie

Active Member
Joined
May 16, 2011
Just replaced springs & intake seals (on car) and now have an annoying puffing at idle when punching throttle then decel then punch again. Blue oil smoke, runs good no miss, plugs are clean & even, compression checks OK, no smoke on pull or deceleration from hi RPM to idle.
Rumor has it there are various seals from other sources that will fit on exhaust guide with some success (stock cam & valves) ??
Any info, part #s, description or experience with this is as always appreciated :banghead:
 
You can't put seals on the factory exhaust valves. They have a step on the stem that will destroy the seal.

Posted from the TurboBuick.Com mobile app
 
I looked for that but my exhaust valves looked like the intakes?? Where should the step be? Would the step ruin the seal or just dis-lodge it?
 
This is where the notch is located.

IMG_9576.JPG



Intake valve on the left & exhaust on the right. Hope this helps, I know you have been working hard on it.

Mike
 
Thanks for the info!!! But would a stock cam lift the valve to this point ??? I am hoping just basic head to guide seal will help!! Remember this car never did this until I changed the springs............???
 
Thanks for the info!!! But would a stock cam lift the valve to this point ??? I am hoping just basic head to guide seal will help!! Remember this car never did this until I changed the springs............???

Take a look at the intake valve in the photo above and you can see where the seal has slightly polished the stem in the same area where the step/notch is on the exhaust valve. This was stock valves & cam in my car.



This is a Manley exhaust valve without the step.

IMG_9579.JPG
 
Last edited:
Wont work. You must remove the heads, cut the guides down, and replace the exhaust valves with ones with a smooth stem like the intakes.
I tried running seals YEARS ago on the stock exhaust valves, It doesn't work:rage:
 
Appreciate the input guys but what could have caused this sudden puffing at idle since spring change??
And what can be done without pulling heads? :inpain:
 
So you kick it, shut off and kick it again to make it puff smoke?


First, stop doing that.

Second, block off the PCV line and see if it stops.
 
Will try that, but I've done no changes other than springs plus I've had the RJC pcv in for a year now and never had this . I will try to stop doing that if no better answers come up...:stop:
 
Check to see if your valve seals popped off and are just riding along with the valve. Should be easy to check, pull off the valve covers and use an inspection mirror.
 
Done. actually I replaced the springs leaving the old seals on (they were in good shape) then the puffing began I pulled the intakes off to check if a seal had pulled with the new springs but all was ok so I replaced the seals at that time but no improvement. I'm open to any suggestions (y)
 
When I do spring swaps I always put an umbrella seal on the exhaust side to keep some of the oil off the guide. It's not a positive seal and actually will travel up and down with the valve itself. If your smoking problem is due to oil getting past the exhaust guides this should clear it up.

Neal
 
Sounds like what we did with small block Chevy heads back in the day, can you give me some info on seals that may work, please
 
I don't have a P/N off hand for the umbrella seals but they are the same ones you would use on a SBC.

Neal
 
I have the same problem here. Always figured it was worn guides but had them checked at a reputable race shop and said they were fine. Plugs are clean, car runs good, good compression, new pcv, rebuilt turbo by bison two years ago with little drive time. Puffs on startup and throttle blips. Nothing on cruise and boost. After chasing it for 5 years Ive given up
 
I have the same problem here. Always figured it was worn guides but had them checked at a reputable race shop and said they were fine. Plugs are clean, car runs good, good compression, new pcv, rebuilt turbo by bison two years ago with little drive time. Puffs on startup and throttle blips. Nothing on cruise and boost. After chasing it for 5 years Ive given up

I am wondering what kind of seals you have on the intake and exhaust valves?

Did the shop that checked the valve to guide clearance give you clearance measurements after they did their checking?
 
Nope. Also no seals on the exhaust side, still factory setup. I'm not the only one still running heads like this but I'm the only one having problems.
 
Top