Hardened Valve Seats

General help and support for your Lindeman through 2010 John Deere crawler
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Jerrye

Hardened Valve Seats

Post by Jerrye » Wed Feb 10, 2021 9:27 am

I have read that when rebuilding the head on a JD 420 you should install hardened valve seats due to the unleaded gas we use today. I also understand that the 420 did not have replaceable valve seats. Would you have a machine shop machine the head to accept the hardened seats and install them? Would you do the intake valves also or just exhaust?
Jerry

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Lavoy
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Re: Hardened Valve Seats

Post by Lavoy » Wed Feb 10, 2021 9:48 am

Yes, done by a machine shop. If the existing seats show much wear, I would have both done, otherwise, they usually only do exhaust.
Lavoy
Parts and restoration for antique and late model John Deere crawlers.
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