The difference in M through 450 GAS manifolds ??????

mike1972chev · Jul 30, 2013

Me again,

I recently pulled my manifold off of my 53 Super M to get it milled. (and since it was off,I had it "Jet-X" coated as well

I noticed it did not look like a lot of used manifolds OR new replacement manifolds I see on EBAY.In the 2 photos,mine is IDENTCAL to the photo labeled #1and has an I.H part # on it. It looks to have an air gap between the intake and exhaust sides if the manifold. Possibly for keeping the intake charge cooler on the inlet side?????? (IDK)

The one labeled #2 is a common one I see for sale a lot.

What are the diffences in the M-450 GAS manifolds. Are there MANY different I.H. versions of these??????? (I know M$W and other companys build custom ones also.)

sflem849 · Jul 30, 2013

Your manifold is "the best" manifold. Yes, they all fit each other. BUT yours is the 450 version which makes .02% more hp compared to the stock M manifold. (I don't know the numbers, but it isn't much but is more)

Hugh McKinney · Jul 30, 2013

Well, your #1 manifold looks just like my 450 LP gas manifold. Like maybe they were running short on gasoline manifolds that day and they substituted LPG? Sure looks like one to me. The #2 just looks like a gasoline M/400/450 manifold.

CenTex Farmall · Jul 30, 2013

As Sflem says, it makes for a little bit cooler intake charge and compression ratios were creeping up thus wanting a little cooler charge.

The threaded port with the plug was for Nitrous....

D Slater · Jul 30, 2013

Top picture came out around the time 450 tractors started being built for gasoline tractors. Also used by IH for replacement on M to 450 gas tractors and W tractors until IH quit making manifolds. Other picture is a original SM gasoline manifold. Know the serial number break for the SM type manifold it started on some of the last M tractors. Don't know the exact change over for some others. Basically the SM type was used until 400 tractors came out. 400 tractors used a different gas one. Pictured in parts and pieces. Then LP, kerosene, distillate and the early tractors with 3/8 manifold to head studs instead of 7/16. SM type you picture was also used on some SM LP tractors until the divorced intake to exhaust type for LP came out.
Look in parts and pieces and type in farmall manifold. I put pictures of 4 gas type manifolds with my name beside them a long time ago. Probably can find a LP picture and others in manifolds.

mike1972chev · Jul 30, 2013

Thanks guys, As usuall,you have some great answers with good details.

D beatty · Jul 30, 2013

The plug on the intake was used to do a vacuum test on engine.

mike1972chev · Jul 31, 2013

I wondered what the 1/8 pipe plug was for????

But I like Centex's answer about the Nitrous as well!

lol

mkirsch · Jul 31, 2013

That vacuum port also works to run a milking machine. We milked many a down cow out in the pasture with an old surge bucket milker running off the M. One of the most miserable jobs known to man. I'd rather pick stone or stack hay than deal with a down cow.

sflem849 · Jul 31, 2013

(quoted from post at 05:27:50 07/31/13) That vacuum port also works to run a milking machine. We milked many a down cow out in the pasture with an old surge bucket milker running off the M. One of the most miserable jobs known to man. I'd rather pick stone or stack hay than deal with a down cow.

I have seen a few around here that have a valve and pipe nipple on them for a quick hookup.

D beatty · Jul 31, 2013

Back when these manifolds were made nobody thought about Nitrous in these engines.

D Slater · Jul 31, 2013

Also on early SM LP tractors that used a manifold like in the bottom picture a tee screwed in where the plug is. Lines from it went to the regulator and the LP type carburetor. Later LP tractors with a different manifold also used the opening for same.

sflem849 · Jul 31, 2013

(quoted from post at 19:06:06 07/31/13) Also on early SM LP tractors that used a manifold like in the bottom picture a tee screwed in where the plug is. Lines from it went to the regulator and the LP type carburetor. Later LP tractors with a different manifold also used the opening for same.

Why was that necessary?

The difference in M through 450 GAS manifolds ??????

mike1972chev

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sflem849

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Hugh McKinney

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CenTex Farmall

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D Slater

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mike1972chev

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D beatty

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mike1972chev

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mkirsch

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sflem849

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D beatty

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D Slater

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sflem849

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