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Gouged Valve Stem Tip

I'm getting ready to install the heads back on my motor and I noticed this gouge in the #1 exhaust valve stem tip. Not sure when or how this happened.

This is a problem, right? Should I have the tip ground to fix this?

Thanks!



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Ward Komers
1984 944 Track Car - Sold
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Old 08-18-2025, 06:17 PM
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Hi
Stone or polish off any high material and it will be fine under a standard Porsche swivel foot.
Cheers
Old 08-18-2025, 09:17 PM
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Henry Schmidt's Avatar
 
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That is a strange pattern suggesting a manufacturing defect not impact destruction.
I would pitch the valve in favor of a replacement.
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Old 08-19-2025, 07:17 AM
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I'm in Henry's camp. Considering the consequences of a dropped valve, best to replace it.
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Old 08-24-2025, 02:35 AM
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It looks more like it got beaten out of the guide.

On the other side of the valve grinding machine is the stone to bring it back to "stock." The length of the valve tip protruding from the head is ground down to match how much is taken off of the valve seat during the valve job to keep the rocker geometry stock. They should all be equal, at least in a perfect world. If you don't have access to valve grinding equipment replacing the valve would be the easiest and cheapest way to correct.
Old 08-24-2025, 09:09 AM
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Quote:
Originally Posted by dannobee View Post
It looks more like it got beaten out of the guide.

On the other side of the valve grinding machine is the stone to bring it back to "stock." The length of the valve tip protruding from the head is ground down to match how much is taken off of the valve seat during the valve job to keep the rocker geometry stock. They should all be equal, at least in a perfect world. If you don't have access to valve grinding equipment replacing the valve would be the easiest and cheapest way to correct.
If the valve was damaged during an attempt to pound the valve out of the guide, what are the chances that the stem is still within spec?
We very rarely surface the tip end of the valve even though the machine has that capability. If you grind a Porsche valve enough that you need to shorten the stem, the head rim is already too thin.
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Old 08-24-2025, 10:22 AM
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Thanks for the input everyone. I went ahead and got a new TRW valve from our host. Glad to see "Germany" on the box...

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Ward Komers
1984 944 Track Car - Sold
1968 912 Rust Bucket - Under Repair
1971 911T - Under Repair
Old 08-24-2025, 11:50 AM
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new parts when in doubt.
Old 08-25-2025, 06:57 PM
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As long as the credo: "sometimes new parts don't work" is applied. Inspect everything.

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Old 08-25-2025, 07:39 PM
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