Rick;
It isn't possible to balance a 4-cylinder engine completely, no matter
what you do. All you can do is minimize the vibration.
On the other hand, an in-line 6 cylinder engine or a V-12 can be
balanced but a V-6 or V-8 can't be completely balanced. There are
"rocking couples" that cause vibration in engines that do not have
symmetry.
Now--- someone explain to me the rationale behind a 10- cylinder engine.
??????
Regards, Neil Tucson, AZ
-----Original Message-----
From: owner-land-speed@autox.team.net
[mailto:owner-land-speed@autox.team.net] On Behalf Of Rick Yacoucci
Sent: Monday, October 11, 2004 10:46 AM
To: land-speed@autox.team.net
Subject: Crank Balancing ( Math )
I got a "what if" for the math guru's
Let say you want to take 4 cylinder engine and take out two pistons and
run
it as a two cylinder.
You need to put weight back on the crank journals for the engine to stay
in
balance
But how much weight???........
I would think you would need to put the whole rotating weight of the rod
and
bearing
Plus a portion of the reciprocating weight of the whole piston and rod
assembly
The firing order is 1-2-4-3 so we would either run 2 and 3 or 1 and 4
because they run 360 deg apart
Rod weight
Total Weight 346 grams
Rotating Weight 251 grams
Reciprocating Weight 95 grams
Center to center 4.775
Main bearing weight 23.5 grams
Complete Piston weight 293.3 grams
Rick
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