Farm Equipment - Allis 426 vs Cat Challenger 403

Print Page | Close Window

Allis 426 vs Cat Challenger 403

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=192690
Printed Date: 08 Sep 2025 at 11:43am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Allis 426 vs Cat Challenger 403

Posted By: bigal121892
Subject: Allis 426 vs Cat Challenger 403
Date Posted: 01 Jan 2023 at 6:22pm

The Allis 200 topic, got me to thinking about a question I've wondered about for sometime. The 426 in the 7080 and the 7580 produced 210 Hp at 2550 RPM, but the Cat 403 in the Challenger 45, was able to produce 240 Hp at 2100 RPM. Did Allis spin them that fast just to get the torque down to save on the drive train?

Replies:

Posted By: DrAllis
Date Posted: 01 Jan 2023 at 6:29pm

Transmission and lower end of the engine to keep torque at higher speeds. Input gears to the power director trans were different ratio (faster than 7030/50) to increase trans life as well.

Posted By: bigal121892
Date Posted: 01 Jan 2023 at 7:17pm

Thanks for the info Doc.

Posted By: DrAllis
Date Posted: 01 Jan 2023 at 8:25pm

The 7580 was 222 flywheel HP, 12 hp more than a 7080.

Posted By: victoryallis
Date Posted: 02 Jan 2023 at 6:52am

Al an 8.3 in a 7580 makes a great combo until something goes wrong in the tranny. Probably ok as long as your conservative with the smoke screw. I can’t say that about whoever did my conversion.

-------------
8030 and 8050MFWD, 7580, 3 6080's, 160, 7060, 175, heirloom D17, Deere 8760