Valve Sticking?

rotorwrench said:
Many of the late replacement valves are stainless steel. This always leaves the possibility for problems when used with an iron guide........
If a person runs all stainless valves, they might consider a bronze/brass guide insert for the old iron guides.
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Quality SS 1.5"/1.6" Chevy (flathead) exhaust valves, like those from Manley, have chrome stems that should minimize/eliminate any problems with iron guides.
 
This new gas puts a thin white resin film on the stems and causes sticking or a slight burb. Add MMO to every tank of gas to prevent it. G.M.
 
alan said:
I guess that in AZ they are upside down- oh wait I thought it was in NZ- apparently they can't get flexiable nozzle pump spray guns in AZ
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nahh, just commenting on why he would rather pull the engine rather than get in there to pull the intake, etc...lol....Mike
 
Hi all I think I have a similar issue with a valve but I can can't pin point it. I can hear it coming out of the exhaust pipe. The car drives ok but you hear this hi pitched noise from the pipe. It is a bit hard to explain. I checked my valve clearance which was ok cracked valve? Tired spring? Any suggestions. Also this might be a stupid question what is MMO or something you guys are talking about Ive have not heard of this in Australia thanks again. Jason
 
MMO = Marvel Mystery oil.

Just a suggestion -- put your location in your Intro.
There maybe someone on here that is near by you that can help.
 
Bud.had the very thing on a old engine I picked up last week,did a compression CK ,no 5 cyl had 0 pressure ,pulled intake,and ex V would not close,but would move some,,engine was on stand so removed head and valve assembly,valve had a little crud buildup around upper end ,pretty sure mmo would have solve problem if engine had been run some.any way,I have the tools to remove & install valves if you need them.Don
 
Jason, if all looked good under the intake manifold, I think your gonna have to tug the heads. You could try a compression or leak down test.
That will probably tell you what's going on.
Martin.
 
Thank you to "rotorwrench" for his in depth technical discussions, bringing in other frames of reference, greatly assists in my own comprehension of material dynamics.
 
Now you know why we replace all valve springs during an overhaul. Springs that have been compressed for very long times actually take a "set" that prevents dependable valve closure.
 
You can always use a vacuum gauge. Just hook it up to the intake manifold and if it reads constant its fine, if it jumps up and down it will tell you if its sticking. You do have to have the motor running while doing it.
 
This is and old thread but good info May 2013
I heard of one the other day were the valve froze to guide and pulled it down I guess back and forth until the clip that hold guide in place fell out.
Look up top with intake off you can see that way.
 
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