Taller roller lifter bodies better for unbushed block?
#1098117
10/20/11 11:57 AM
10/20/11 11:57 AM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
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OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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Two blocks: - one being freshened up that already has bushed lifter bores - one for new build-up that retains OEM unbushed lifter bores
Two sets of IMM BB lifters: - one low-use set of earlier style w/ taller lifter body - one new set of current style w/ shorter lifter body
Assumption: The earlier style w/ the taller body would be better suited to the block that does NOT have bushed lifter bores because the taller body will be more stable in shorter unbushed bore.
Assumption valid?
NOTE: Picture showing different body styles is showing a damaged tall-body lifter from someone else's engine, not one that I'm using.
Last edited by BradH; 10/20/11 12:00 PM.
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Re: Taller roller lifter bodies better for unbushed block?
[Re: BradH]
#1098124
10/21/11 01:39 AM
10/21/11 01:39 AM
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Joined: Oct 2007
Posts: 4,210 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,210
New York
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Taller lifter makes the same diameter pushrod shorter = stiffer. Example only: if the PR is 10" ball to ball, and the ends are 1/2" each, the tube is 9". Running all the same parts in an 8-1/2" tube (9-1/2" OAL) is almost 19% stiffer.
Boffin Emeritus
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Re: Taller roller lifter bodies better for unbushed block?
[Re: BradH]
#1098126
10/21/11 11:36 AM
10/21/11 11:36 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Re: questions / comments above...
1. Both blocks are OEM 440 RB.
2. In this example, the pushrod length is the same w/ both styles of lifter; the taller body simply extends above the pushrod seat vs. being machined even with pushrod seat.
In that case I would use the shorter lifter... less over all weight
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