Wow. How cool is that. Solves exactly the set of problems I've experienced.
Why didn't I think of this.
-----Original Message-----
From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net] On Behalf
Of Chris Kantarjiev
Sent: Monday, August 07, 2006 8:15 AM
To: fot@autox.team.net
Subject: RE: [FOT] Fuel Pressures
Long ago, when I was devouring everything I could about race car prep, I ran
across a passage in the Dave Bean Engineering catalog about mounting DCOEs
on four cylinder engines. It ran something like this ...
no, exactly like this, since I still have that very useful catalog on my
shelf:
---
Although there is little to choose between the performance of thackeray
wahser and rubber cushion grommets, each has its own durability problem.
Thackeray washers experience metal fatigue, as any spring will, and break,
thus collapsing and reducing o-ring compression. The culprit, of course, is
high frequence engine vibration. 7,000 rpm seems to be the magic number.
Above that, 20 to 50 hours of running is about all you can expect of the
upper thackerays (which are the ones that fail; the lower ones have little
load on them and live forever).
The cushion grommets don't have this problem, but do have one of their own.
The inevitable fuel leakage out of the carb-manifold joint will eventually
attack and rot the lower grommet. The upper ones, of course, have little
fuel contact and last forever.
VOILA! Use thackerays on the bottom and grommets on the top for optimum soft
mount life. Simply purchase an extra pair of cushion grommets and washer for
each soft mount kit you buy. Then keep the leftover pair of thackerays in
your toolbox as spares. Sometimes the obvious escapes us.
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