[AT] [External] Re: Valve Seat Inserts

[Jim Becker]

Some time in the mid/late ‘50s, IH started using nodular iron in places on tractors where you would have otherwise seen cast iron.  It obviously wouldn’t have applied to any letter series Farmall.  But I wonder if that is what those machine shops were running into with the truck heads.  Don’t know.

Jim Becker

From: Howard Pletcher 
Sent: Friday, December 04, 2020 9:33 PM
To: Antique Tractor Email Discussion Group 
Subject: Re: [AT] [External] Re: Valve Seat Inserts

IH truck gas engines also had quite hard heads without inserts, hard enough that reportedly some shops thought there were already inserts in them when they tried to work on them.  Few problems seem to have developed in the years since lead was dropped.  I believe it is the material used in the castings, not heat treating.  But these engines were designed for extended use at wide open throttle in trucks like the Loadstar so they are not stressed in smaller trucks like pickups and Scouts.

Different Divisions of IH, different foundries, different engineers.  But perhaps they did talk to each other.

Howard

On Fri, Dec 4, 2020 at 1:59 PM Jim Becker <mr.jebecker at gmail.com> wrote:

  The only reference I found that directly addresses this is the I&T Shop Manual.  I presume it is accurate although it is not first-hand IH material.  According to it, the M, 6, and 9 series non-Diesels used inserts for the exhaust valve seats.  The H did not but the Super H and Super 4 series did.  The Diesel M, 6, and 9 series did not use inserts.

  The higher compression of a Diesel translates into a higher temperature in the chamber prior to ignition.  I don’t know if that translates to higher temperature after ignition and completion of the power stroke.  I suspect not.  Diesel fuel itself isn’t that great of a lubricant but is a better one than gasoline.  That may make enough difference for IH to have decided to not use hardened inserts in Diesels.  Nothing in the above eliminates the possibility of hardening the seats that were ground into the Diesel heads.  IH was big on induction hardening and applied it to a lot of things.  I am not aware of them heat treating cast iron parts.

  Jim Becker




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