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<DIV>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.</DIV>
<DIV> </DIV>
<DIV>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.</DIV>
<DIV> </DIV>
<DIV>Jim Becker</DIV>
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<DIV style="font-color: black"><B>From:</B> <A title=soffiler@gmail.com>Stephen
Offiler</A> </DIV>
<DIV><B>Sent:</B> Friday, December 04, 2020 7:26 AM</DIV>
<DIV><B>To:</B> <A title=at@lists.antique-tractor.com>Antique Tractor Email
Discussion Group</A> </DIV>
<DIV><B>Subject:</B> Re: [AT] [External] Re: Valve Seat
Inserts</DIV></DIV></DIV>
<DIV> </DIV></DIV>
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style='FONT-SIZE: small; TEXT-DECORATION: none; FONT-FAMILY: "Calibri"; FONT-WEIGHT: normal; COLOR: #000000; FONT-STYLE: normal; DISPLAY: inline'>
<DIV dir=ltr>That's a very good question. I don't know about the MD
specifically, but in very general terms, diesels get their increased fuel
efficiency primarily from the high compression ratio, which means high
combustion temperatures, which at least suggests that even older diesels used
some kind of hard seat (induction hardened, or a hardened insert).
<DIV> </DIV>
<DIV>SO</DIV>
<DIV> </DIV></DIV>
<DIV> </DIV>
<DIV class=gmail_quote>
<DIV class=gmail_attr dir=ltr>On Fri, Dec 4, 2020 at 8:16 AM Bill Brueck
<<A>bill@apluscomputer.com</A>> wrote:<BR></DIV>
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<P class=MsoNormal>How does this all relate to diesel engines? Was lead
added to diesel fuel in those days, or were the engines (valve seats) designed
to not need the lead? <U></U><U></U></P>
<P class=MsoNormal><U></U><U></U> </P>
<P class=MsoNormal>Thinking of my Farmall MD, which father in law bought
new. It hasn’t seen enough hours for years to matter, I expect.
When I joined the family in the late 60’s it was already largely
retired. I remember running a rotary hoe with it once.<U></U><U></U></P>
<P class=MsoNormal><U></U><U></U> </P>
<DIV>
<P class=MsoNormal>B²<U></U><U></U></P>
<P class=MsoNormal>Bill Brueck<U></U><U></U></P>
<P class=MsoNormal> Pine Island, MN USA<U></U><U></U></P></DIV>
<P class=MsoNormal><U></U><U></U> </P>
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<P class=MsoNormal><B>From:</B> AT <<A
target=_blank>at-bounces@lists.antique-tractor.com</A>> <B>On Behalf Of
</B><A target=_blank>drgerber@bright.net</A><BR><B>Sent:</B> Friday, December
4, 2020 6:56 AM<BR><B>To:</B> 'Antique Tractor Email Discussion Group' <<A
target=_blank>at@lists.antique-tractor.com</A>><BR><B>Subject:</B> Re: [AT]
[External] Re: Valve Seat Inserts<U></U><U></U></P></DIV></DIV>
<P class=MsoNormal><U></U><U></U> </P>
<P class=MsoNormal><SPAN
style='FONT-SIZE: 14pt; FONT-FAMILY: "Calibri Light",sans-serif'>The hardened
seat installation was more needed for high RPM engines with high
compression. That certainly does not apply to old 2 cylinder John Deere
engines; low compression in comparison, as well as low RPM made to run on
cheap fuels. I have had to get the machine shop to put valve seats in
two old Deeres; one was an LA which has a flat head and where the seats are in
the block; it had been overhauled several times; countless hours of abuse by a
couple of previous owners; and the engine was so loose it would build up
compression in the pan and blow the breather cap 50 feet in the air. It
needed new valve seat inserts to make it run again. The other was an MT
where the head was pretty destroyed but salvageable. It had sentimental
value as it was worn out when I purchased it many years ago. My father in law
got scared once bush hogging with an old B with a hand clutch. I was
overseas in the Army, and when I got back to the US I bought the MT because it
had a foot clutch and he was taking care of the farm and the fields in the
soil conservation program had to be mowed. That poor thing bush hogged
through material as tall as the tractor, and he literally wore it out. I
restored it last year, have way too much money in it, but it will stay in the
family. <U></U><U></U></SPAN></P>
<P class=MsoNormal><SPAN
style='FONT-SIZE: 14pt; FONT-FAMILY: "Calibri Light",sans-serif'><U></U><U></U></SPAN> </P>
<P class=MsoNormal><SPAN
style='FONT-SIZE: 14pt; FONT-FAMILY: "Calibri Light",sans-serif'>Dave Gerber
<U></U><U></U></SPAN></P>
<P class=MsoNormal><SPAN
style='FONT-SIZE: 14pt; FONT-FAMILY: "Calibri Light",sans-serif'>Ohio<U></U><U></U></SPAN></P>
<P class=MsoNormal><SPAN
style='FONT-SIZE: 14pt; FONT-FAMILY: "Calibri Light",sans-serif'><U></U><U></U></SPAN> </P>
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<P class=MsoNormal><B>From:</B> AT <<A
target=_blank>at-bounces@lists.antique-tractor.com</A>> <B>On Behalf Of
</B>Jim Becker<BR><B>Sent:</B> Thursday, December 3, 2020 11:36
PM<BR><B>To:</B> Antique Tractor Email Discussion Group <<A
target=_blank>at@lists.antique-tractor.com</A>><BR><B>Subject:</B> Re: [AT]
[External] Re: Valve Seat Inserts<U></U><U></U></P></DIV></DIV>
<P class=MsoNormal><U></U><U></U> </P>
<DIV>
<DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-SIZE: 12pt; COLOR: black">As far as I
could see, the whole hardened valve seat problem was a lot of Chicken
Little. Back when most of these old tractors (and old cars) were made,
regular gas had little to no lead in it anyway. Tractors in particular
were designed to run on the lowest octane gas commonly available. Many
just used valve seats ground straight into the cast iron and ran for
decades. The biggest exception was probably the LP heads that came with
hardened seats made for some engines. As leaded gas started getting
harder to find, machine shops all over the country were cutting out perfectly
good valve seats and sticking in replacement seats. Even if the worst
fears happened and there was excessive seat wear, the fix would still just be
to install valve seats. Worst case is the same as the preemptive
treatment!<U></U><U></U></SPAN></P></DIV>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; COLOR: black"><U></U><U></U></SPAN> </P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-SIZE: 12pt; COLOR: black">Was a waste of
effort.<U></U><U></U></SPAN></P></DIV>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; COLOR: black"><U></U><U></U></SPAN> </P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-SIZE: 12pt; COLOR: black">Jim
Becker<U></U><U></U></SPAN></P></DIV>
<DIV>
<DIV>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma,sans-serif; COLOR: black"><U></U><U></U></SPAN> </P></DIV>
<DIV>
<DIV>
<P class=MsoNormal style="BACKGROUND: whitesmoke"><B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma,sans-serif; COLOR: black">From:</SPAN></B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma,sans-serif; COLOR: black"> Jason
<U></U><U></U></SPAN></P></DIV>
<DIV>
<P class=MsoNormal style="BACKGROUND: whitesmoke"><B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma,sans-serif; COLOR: black">Sent:</SPAN></B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma,sans-serif; COLOR: black">
Thursday, December 03, 2020 8:24 AM<U></U><U></U></SPAN></P></DIV>
<DIV>
<P class=MsoNormal style="BACKGROUND: whitesmoke"><B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma,sans-serif; COLOR: black">To:</SPAN></B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma,sans-serif; COLOR: black"> Antique
Tractor Email Discussion Group <U></U><U></U></SPAN></P></DIV>
<DIV>
<P class=MsoNormal style="BACKGROUND: whitesmoke"><B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma,sans-serif; COLOR: black">Subject:</SPAN></B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma,sans-serif; COLOR: black"> Re:
[AT] [External] Re: Valve Seat
Inserts<U></U><U></U></SPAN></P></DIV></DIV></DIV>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; COLOR: black"><U></U><U></U></SPAN> </P></DIV></DIV>
<DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-SIZE: 12pt; COLOR: black">Yes. Lead in
addition to be an antiknock agent also coated the valve seats to prevent wear
on valve seats. Only the exhaust seats need to be replaced.
<U></U><U></U></SPAN></P>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; COLOR: black"><U></U><U></U></SPAN> </P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-SIZE: 12pt; COLOR: black">Very old low
compression motors often don't need this done because their combustion
temperatures are so low.<U></U><U></U></SPAN></P></DIV>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; COLOR: black"><U></U><U></U></SPAN> </P></DIV>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; COLOR: black">Jason<U></U><U></U></SPAN></P></DIV></DIV>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; COLOR: black"><U></U><U></U></SPAN> </P></DIV>
<DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-SIZE: 12pt; COLOR: black">On Thu, Dec 3,
2020, 8:08 AM Gunnells, Brad R <<A
target=_blank>brad-gunnells@uiowa.edu</A>>
wrote:<U></U><U></U></SPAN></P></DIV>
<BLOCKQUOTE
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<P class=MsoNormal><SPAN style="FONT-SIZE: 12pt; COLOR: black">Wasn't there
something also with the change from leaded to unleaded fuels? For some
reason I thought manufacturers started putting harder valve seats in later
model engines due to the limiting of lead. I could be way off here but I
thought I'd heard about that back in my dirt track racing
days.<BR><BR>Brad<BR><BR>On 12/3/20, 12:57 AM, "AT on behalf of Dean VP"
<<A
target=_blank>mailto:at-bounces@lists.antique-tractor.com%20on%20behalf%20of%20deanvp@att.net</A>>
wrote:<BR><BR> Steve,<BR><BR> AHA,, I
completely overlooked they were two different parts. Now the
lights<BR> go on. Now I understand. The valve seat
might be damaged but the guide may<BR> still be good or
vice versa. As I recall that was more of a problem in
the<BR> 40's and 50's than it is
now.<BR><BR> Dean VP<BR> Apache
Junction, AZ<BR><BR> -----Original
Message-----<BR> From: AT <<A
target=_blank>at-bounces@lists.antique-tractor.com</A>> On Behalf Of
Steve W.<BR> Sent: Wednesday, December 2, 2020 11:38
PM<BR> To: Antique Tractor Email Discussion Group <<A
target=_blank>at@lists.antique-tractor.com</A>><BR>
Subject: Re: [AT] Valve Seat Inserts<BR><BR> Dean VP
wrote:<BR> > Found a term in this company's price list
that rings some memories<BR> > but really hazy
ones. Could someone explain when and why
"Valve<BR> > Seat Inserts" are used rather than
replacing the whole valve guide?<BR> > Yes, they are a
little less expensive but not that much Please <BR>
> refresh my hazy memory from the 50's.<BR> >
<BR> > <BR> >
<BR> > Dean VP<BR> >
<BR><BR> Different parts. The valve guide holds the valve
stem and keeps it in<BR> position. The valve seat is the
ground part of the port in the head that the<BR> valve
face seals against. The reason for the inserts are a few, one is
that<BR> you might have a head with damaged or eroded
seats and the valves won't<BR> seal. You machine out the
worn/damaged area, press in the inserts and either<BR>
peen the edge or more commonly you bore the area for the seat with a step
so<BR> the seat locks into the head, to install you freeze
the insert and heat up<BR> the head. Then the two parts
lock together as the temperatures normalize.<BR> Have done
both and prefer the second option.<BR><BR>
--<BR> Steve W.<BR>
_______________________________________________<BR> AT
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