By now about all SM engines have been rebuilt to the same cubic inch as a 450. If both used original gasoline heads the 450 would have more compression with standard pistons and its original camshaft and manifold also gave it a little more power. Lots of combinations of parts that could be put in over the years results in no clear cut answer to the question of performance. Also up into the 1960 tees IH sold replacement blocks with C281 on them that got used in SM tractors. Several around that just have the block changed with all SM parts used with the block. If thats what the tractor is you probably have the same setup as a SM with a replacement block hurting originality.
IH tests with fire crater standard altitude pistons used show only a 1.5 horse power increase with the 450. They recomended a 400 camshaft be used for more power in the SM and I think they used it testing the SM.
Also interesting was the fuel use at 1450 RPM. 450- 4.8 to 5.2 a hour.
SM-4.5 to 4.9 a hour.
This post was edited by D Slater at 07:28:26 09/26/12.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - When Push Comes to Shove - by Dave Patterson. When I was a “kid” (still am to a deree) about two I guess, my parents couldn’t find me one day. They were horrified (we lived by the railroad), my mother thought the worst: "He’s been run over by a train, he’s gone forever!" Where did they find me? Perched up on the seat of the tractor. I’d probably plowed about 3000 acres (in my head anyway) by the time they found me. This is where my love for tractors started and has only gotten worse in my tender 50 yrs on this “green planet”. I’m par
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
