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How to tell if I have inconal or stainless exhaust valves

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How to tell if I have inconal or stainless exhaust valves

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Old 12-06-2005, 06:25 PM
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Default How to tell if I have inconal or stainless exhaust valves

I am rebuilding my heads and wondering how to tell if I have inconal or stainless exhaust valves. A magnet will stick to the intakes but not the exhaust. There are no markings on the valves either. The exhaust valves are stock length 3/8 stem 1.88 dia and weigh 137 grams.
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Old 12-08-2005, 10:27 PM
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Default Re: How to tell if I have inconal or stainless exhaust valves

ttt
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Old 12-08-2005, 11:14 PM
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Default Re: How to tell if I have inconal or stainless exhaust valves

Magnetic at one end and not at the other.
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Old 12-09-2005, 09:16 AM
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Default Re: How to tell if I have inconal or stainless exhaust valves

Originally Posted by formula31
Magnetic at one end and not at the other.
Do you mean at each end of the valve or intake vs exhaust?

all my stainless props are magnetic
all my stainless bolts are not

could some stainless valves ever be magnetic?
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Old 12-09-2005, 09:44 AM
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Default Re: How to tell if I have inconal or stainless exhaust valves

Yea, each valve by itself, it MAY be inconel if the valve is magnetic at one end, (I dont remember which end) and not at the other. Many types of stainless steel are magnetic.

I have never heard of inconel intake valves.

There should be some laser numbers on the stem near the tip of the valve.
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Old 12-09-2005, 04:02 PM
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Default Re: How to tell if I have inconal or stainless exhaust valves

1. Replace the exhaust valves with Inconel.
or
2. Assume they are Inconel, drop a valve and then you would know.

I have seen both ways exercised, but in reverse order.
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Old 12-09-2005, 08:37 PM
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Default Re: How to tell if I have inconal or stainless exhaust valves

Originally Posted by RLW
1. Replace the exhaust valves with Inconel.
or
2. Assume they are Inconel, drop a valve and then you would know.

I have seen both ways exercised, but in reverse order.


Good Advice!
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Old 12-10-2005, 08:48 AM
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Default Re: How to tell if I have inconal or stainless exhaust valves

YES, what RLW said! My engine builder says that once they are out of the box there is no way to know for sure short of metalurgical analysis of some of the valve material itself. You could sacrifice one and pay for the test and assume that the rest were the same, I suppose. And I also don't believe that anyone makes an inconel or comparable intake valve. It's just not necessary cause they don't have to deal with the heat. --- Jer

Last edited by jpclear; 12-10-2005 at 08:53 AM.
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Old 12-10-2005, 09:45 AM
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Default Re: How to tell if I have inconal or stainless exhaust valves

In the box isnt absolute either. No telling about the manufacturer, distributor or retailer. If they have the magnetic traits, and the right Manley numbers, your probably ok, Or you could just buy a new engine as we all have too much money anyway.
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Old 12-10-2005, 12:32 PM
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Exclamation Re: How to tell if I have inconal or stainless exhaust valves

Factory intake valves are steel. Replace them as well. Feria, Manley, REV, all make good stainless intake valves. The intake valve does not have to be as good as the exhaust valve, Intake valves are bigger and displace more heat into the head via the valve seat. Unless you are sure the exhaust valves are Inconnel, Buy Inconnel ! Make sure you have the right valve springs, I'd buy new one's as well. An Inconnel valve isn't the whole answer, especially when a over revved or fataguied spring breaks and a piston hit's the Inconnel valve. Even built by professionals, with the best parts, catastrophic failure occasionaly happens. Using questional parts, the failure DEFINITELY WILL HAPPEN. Maybe in 2 minutes, 2 hours, 2days , 2 months, 2 years. Why chance it !
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