Date: Tue, 16 Feb 1999 00:31:30 -0800
Reply-To: Doug Jones <duge4wd@EMAIL.MSN.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Doug Jones <duge4wd@EMAIL.MSN.COM>
Subject: Re: 2.1L Wasserboxer Power Rebuild
Its a fact of physics I suppose, that there will be some crank flex at high
rpms with an unbalanced load. The difference in seeing the damage could be
what the journals (and the case/block) can handle. T1 engines are magnesium
(easily cracked), T4s are aluminum, and I assume (but, don't know) that
wasserboxers are aluminum as well. But your Robert's brother's straight
eight is probably iron, and the journals may be thicker and stronger, also
the crank may have been better balanced from the factory than a VW opposed
4. Maybe the whip in the buick crank doesn't rear it's ugly head until very
high rpms due to a slightly better balance.
Any unbalanced crank load could produce some crank flex and hammer a main
journal , although I'm sure with VW engines it's probably above 5000rpms
that this gets bad. Perhaps the straight eight was able to run so well
without such flex symptoms b/c it could survive greater wear (less strict
tolerances), also the iron block may not be subject to the cracking that VW
engines will experience (at least air-cooled VWs, that is); thus, the buick
would wear, but not suffer failure.
I'm sure the flex is probably there; but, unless the VW engine is constantly
run above 5000rpms, it will probably take a substantial beating before the
saddle egg-shapes or the case cracks. Whether it's worth it to buy a
counter-weighted crank is really up to the builder, and how long he/she
wishes the engine to go between rebuilds. (AND how much money they wish to
spend for the piece of mind they get knowing it's there, my engines are not
counter-balanced at present and I sleep fine. I'll sleep just as good after
I probably spend the money, too. But, I'll admit that I've never cracked
open a wasserboxer, so for whatever it's worth I've said it.)
Doug Jones
Robert Alexander wrote:
>I'm not really sure. Brother Gene, back in '65, built an NHRA
>rail dragster, "D-Dragster", running a Buick in-line 8-cylinder, with
>THREE main bearings and never seemed to have any problems with "flexing"
>of the crank, even though he cranked the Buick engine to 6,000 rpm at
>the strip!
>
>I just have my doubts about a 1.9 or a 2.1 VW water-cooled having ANY
>problems with crank "flexing", unless one is turning greater than 8,000
>rpm.
>
>BOB
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