Date: Sun, 11 Feb 2001 16:31:00 EST
Reply-To: NotaJeep@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Steven Denis <NotaJeep@AOL.COM>
Subject: Re: 2.1L Oil pressure problem: Rods: SYMPTOM NOT CAUSE:
UNBALANCED crank the ...
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In a message dated 2/11/01 1:36:58 PM Eastern Standard Time,
Wolfvan88@AOL.COM writes:
<< Feel free to disagree... >>
Well there seems to be a lot of "hype" there..the counterweights will help
the MAIN bearing life as they will have lower loading..as far as the
flex?..errr... how does adding weight to the throw of the crank PAST the edge
of the main bearing reduce flex? if the crank was flexing enough to change
the position of the rod relative to it's journal, then the center main would
have to move some ungodly distance.
Your Type 1 blew up NOT because of what you DID but because what you DIDN'T
do..Yes, you can bend rods whacking them with a hammer..stretching the bolts?
Man, you'd have to be swinging that sledge hard enough to knock the whole
thing into the neighbors yard! (and clear the 8 foot fence!)...It is not
uncommon for a top end rebuild of ANY engine to become a TOTAL rebuild in
short order.. an "iffy" bottom end will put up with the pressure that leaking
valves and rings can produce..go back to "as new" power and the bearings
just give up..chevy six or the type one four, it makes no nevermind ..
You didn't perhaps, as others have done, rebuild the top end after the thing
dropped a valve? People DO that and don't think about the bent rod.
Ok..So..counterweighted crank? Sure..it can't hurt..take a bit of weight off
the flywheel too and retain the nice idle..
rebush, resize and balance the rods? there is no other way..the loading on
the rod and it's strength are the main reasons that the 2.1's blow...Notice
the "racing" top rings? a whole bunch thinner to prevent ring chatter at the
high piston speed on the 2.1's.
these and stretch bolts are more of the "band aids" of which I spoke.. They
KNEW that the rod was overworked and that is a way to make sure that the cap
stays on the rod..
As far as "why did they stop growing the stroke?"..simple..piston speed is
one and rod angularity is the other...even with "shorty" slipper skirt
pistons (not known for their longevity in "street" engines) most "big" type
one's get wider...long jugs and/or barrel shims..
You can't make the WBX WIDER (ok, you CAN, but remember production tooling
and all that?)
so to pack more stroke in the WBX "box" you'd get REALLY crazy rod angles and
even MORE loading......
I'd be more tempted, if I HAD to worry about it, to use something like a
chevy rod, combined with shorter skirt pistons..but these don't exist as it's
a piston with the conbustion chamber in it...
2.1's? great torque-..keep the RPM under, oh 4 grand and it will be FINE...
but what do I know......
steve
"Hey! nice Jeep, Mister! "
"Look kid, it's NOTAJEEP! "
