Pulling Forum - 426 Lifter Failure

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426 Lifter Failure

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Category: Other Topics
Forum Name: Pulling Forum
Forum Description: Forum dedicated to Tractor and Garden Pulling
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=123005
Printed Date: 24 Nov 2024 at 1:41pm
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Topic: 426 Lifter Failure

Posted By: Mark D.
Subject: 426 Lifter Failure
Date Posted: 07 May 2016 at 8:55pm

Hey guys! Been running stock lifters on our Superfarm and had 2 instances of the bottom of the lifter breaking off and then slowly wearing off the cam lobe before we notice. We were free-reving the engine as high as 5000rpm coming off the line. We have since quit turning it so hard and only come out at 4000rpms. Problem is, our motor seems to "stay on its knees" the length of the track rather than charging hard.

This year we will be trying a set of billet lifters to hold up with the higher rpm better. We do not have the money saved up for a roller-lifter setup just yet. Anyone else out there experience the same issues? Thanks!

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Miss Behavin - D21 Super Farm

Xcessive Tinkering - 190 XT Hot Farm Puller

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Replies:

Posted By: O.P.S. Heads
Date Posted: 07 May 2016 at 11:44pm

I have heard of this but have never experienced it myself. I am not a big fan of excessive valve spring pressure with a stock (reground) camshaft at super farm or LLSS RPM levels. Not sure what your spring pressure is but my buddy runs a seat pressure of 140 PSI. with a 120 lb. per inch spring rate in a 301 twin LLSS. Same RPM and same lifter as a 426 Super farm engine or pretty close - no lifter / camshaft issues for 11 years - knock on wood.

I think your "staying on it's knees" issue is separate from your camshaft / lifter woes.

You may as well go to a roller camshaft and lifters. I would guess everyone you compete against has it. I would have no idea what the optimum camshaft grind should be on a super farm engine. Every engine combination likes something different. Do you have any dyno operators in your area? If so (especially in the super farm class)I would make an appointment and twist her tail. You will learn more in a day than in 10 years of putting it down the track.