Farm Equipment - 301 diesel cranking compression

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301 diesel cranking compression

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=209663
Printed Date: 11 Jan 2026 at 10:30am
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Topic: 301 diesel cranking compression

Posted By: PaulSamwel
Subject: 301 diesel cranking compression
Date Posted: 10 Jan 2026 at 4:00pm

What would be acceptable cranking compression for a cold 301 diesel engine?Thanks.

Replies:

Posted By: injpumpEd
Date Posted: 10 Jan 2026 at 5:09pm

Most diesel engines need at least 300 psi, but 350-400 psi is better. AC procedure was to check it with engine running, which I feel is unnecessary, as long as you have all injectors out and good cranking starter/batteries, with a charger hooked up while doing it.

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210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers!

Posted By: DrAllis
Date Posted: 10 Jan 2026 at 5:21pm

We've checked several over the years and with a good starter (Lucas is questionable) and all injectors removed and a battery charger on the 2 batteries, you'll wind up with 350 to 375 psi. I never saw one hit 400 but maybe at a fresh OH they might.