Inconel valve life span???

Many years. I'm sure there are people here that have a thousand or more hours on them. Excessive heat from running lean will shorten their life as will reversion.
 
You need some 3 in one oil ,gauze pads, and 30 weight ballbearings will keep any thing alive longer......oh and Prestone antifreeze:sifone:
 
You need some 3 in one oil ,gauze pads, and 30 weight ballbearings will keep any thing alive longer......oh and Prestone antifreeze:sifone:

Whata need ball bearings for Gordo?

It is all ball bearings these days, what do you boys need a refresher course? I'm going to my truck, if Fred shows up have him start without me.......
 
Whata need ball bearings for Gordo?

It is all ball bearings these days, what do you boys need a refresher course? I'm going to my truck, if Fred shows up have him start without me.......

Best mechanic lines ever.:26:

Right up there with...

It's a Ciderella story

Can't you see this mans a Nigh

:sifone:
 
Inconel isn't really any stronger than stainless. It's just more heat resistant. Now of course that translates into more durability in a higher performance engine, but in something like a 350-400 horse engine they'd probably be even.

Having said all that, if you aren't in some extreme application like high-lift cams or blowers over 5 psi and you're not running super-lean, you should be able to get 350-400 hours out of a set. Valves are pretty cheap- relative to a broken motor or a lost season. I wouldn't do a top end and reuse them.
 
Is their anything superior to Inconel for exhaust?
.
Unobtainium. But you can't get it. :)

Seriously, some jet turbine blade material like Hastelloy or Waspalloy might be better, but Inconel seems to be accepted as the top dog. That's all we ever used in our Indy car engines, usually made by Del West.
 
Inconel isn't really any stronger than stainless. It's just more heat resistant. Now of course that translates into more durability in a higher performance engine, but in something like a 350-400 horse engine they'd probably be even.

Having said all that, if you aren't in some extreme application like high-lift cams or blowers over 5 psi and you're not running super-lean, you should be able to get 350-400 hours out of a set. Valves are pretty cheap- relative to a broken motor or a lost season. I wouldn't do a top end and reuse them.

I had standard valves in my Merlins this year with about 420-440 hp, had two failures, one last weekend, took out a piston. I talked to Tom at Gellner and he said he does not remember any Inconel failures, he does the head work, he said some guys have 10 yrs on Inconels with no issues..
 
My last boat had 454-400hp Merc Cyclones with Manley inconel exhausts. We owned it for 11 years and put 800 hrs. on it without touching the heads. No problems. My impression is Del West and Ferrea Super Alloy are the best because they are shaped for better flow. Manley are just as tough.
 
How Do IT Know!

The material quality and manufacture method will have more to do with valve life than the material of the valve. Inconel tends to be a little unique in that it is not made as a once piece forging, but a two piece valve and sometimes therin lies a problem. Don't skimp on valve quality and construction. If you subject any valve to uneccessay stesses and abuse it will most likely fail and the result is usally a badly grenaded engine. If your pushing the bigger horsepower numbers from an engine and pushing rpm limits then earlier service and replacement will be critical to the life of the engine and in those cases valve replacement at freshening points is probably a must and much cheaper than replacing the engine. When cylinder and exhaust gas temperatures start reaching higher numbers in supercharging, turbocharging or racing applications the good Inconel valve is just about a must. In normally aspirated moderate compression recreational performance engines well made, good quality stainless such as 21-4n or better valves with proper design, construction and proper installationj will do just fine for hundreds of hours of use.
Valves are obviously not just valves! The devil's in the details!

Best Regards,
Ray @ Raylar
 
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