Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
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The car is a 1991 trans am gta, 5.7L the L98 engine. Like many of us, it smokes blue on startup (only on startup)...
Give me your expert experienced advice on which valve steam seals to use on this thing. The part #'s would be great if any, but anything will do.
I have read on here, the good and bad of 2 types: the umbrella type and the positive seal type.
You guys know best!!! Let me know what you think.
really?
So you used both, factory replacements and the fel pro's? Did you have any seating problems?
Has it solved your smoke on startup, and how long ago did you do them?
Thanks for the help, I'm pretty sure I can get the fel pro's at performace world over here on the queensway...
I usually use the Teflon positive ones such as from Crane or Comp, and no O-rings. But those require machine work, so the ones for you would be the Fel-Pro ones. I usually am not working on an old motor in a car, more normally I'm building one to go fast.
Yes they solve the problem.
I have done countless sets of heads over the years that way, as has ede, in fact he's probably done more than me. Consider either of our choices to be a successful technique.
__________________ "So many Mustangs, so little time..."
I also used the fel pro and the factory Os. No seating problems and cured my start up smoke. I put the positive seals on both the intake and on the exhaust. I also bought new valve cover gaskets from fel pro. Here is the part number for the seals: SS 72527
That's what I wanted to hear, right from the experts!
Thank you both for your help, fel pro's it is.
One other question, are the fel pro stem seals the umbrella type on the exhaust valve or are they just o-type positive seals?
O-rings, which go inside the retainer and keep oil from running down the stem, the factory system;
umbreallas, which ride up and down in the valve stem below the retainer, and do about the same thing, stock on some other motors; and
"positive" seals, which clip around the guide and fit tight to the stem, and thus actually seal.
The Fel-Pro positive ones come in 2 materials, one for intake which seals better since it's more critical, and one for exhaust which don't seal quite as well but stand the heat better.
__________________ "So many Mustangs, so little time..."
Originally posted by Chet I put the positive seals on both the intake and on the exhaust. I also bought new valve cover gaskets from fel pro. Here is the part number for the seals: SS 72527
Aren't you not supposed to use the intake seals on the exhaust? They are made of different materials, and intake on the exhaust would deteriorate over time.
SS72526 [Valve Stem Seal Set Qty: 1] Exhaust; Premium valve stem seals incl.
SS72527 [Valve Stem Seal Set Qty: 1] Intake; Premium valve stem seals incl.
SS72877 [Valve Stem Seal Set Qty: 1] Exhaust; Opt. Hi-Temp. premium valve stem seals incl.
SS72527 is the intake positive seals, as listed above. I don't know what the others are, you'd have to check out a local store and take a look at what's what. Hopefully one of the other 2 listed are the exhaust positive seals.
VS50088R is the valve cover gasket that you will probably need.
That's really helpful, thanks... but what do you guys suggest? Should I use the positive seals on both the intake and exhaust? Or should I just go with the part #'s from fel pro for the intake and exhaust?
waking this up from the dead. Do the heads need machine work to use the felpro set SS72527? or are they a direct replacement?
__________________
Motivational speaker Zig Ziglar states, “Money isn't the most important thing in life, but it's reasonably close to oxygen on the ‘gotta have it’ list;”
85 Z28.
305 carb,mild street cam
700r4 with stock rear end
Shorty headers.
Also I should have asked are they positive lock or the kind that float with the valve
__________________
Motivational speaker Zig Ziglar states, “Money isn't the most important thing in life, but it's reasonably close to oxygen on the ‘gotta have it’ list;”
85 Z28.
305 carb,mild street cam
700r4 with stock rear end
Shorty headers.
Thank you for the fast reply. Now I can get to fixing it.
__________________
Motivational speaker Zig Ziglar states, “Money isn't the most important thing in life, but it's reasonably close to oxygen on the ‘gotta have it’ list;”
85 Z28.
305 carb,mild street cam
700r4 with stock rear end
Shorty headers.
