Billet rod weight?

[Kokamo]

OK, so I've had this on my mind for a bit...when you purchase an ARC rod for any random engine, does that rod have a specific weight compared to a stock rod? You know, to keep balance in check?

Since there's no aftermarket on the Honda GX v-twin motors, I figured I would maybe try to give it a shot and see what happens. I don't have a CNC (I wish I did tho!), but a friend has a humongous machining facility that has everything it takes to custom build anything you could imagine.

Thanks,

~Joe

 

[itsid]

weight of the con rod is not too important since it's no rotating mass (only reciprocating)
the crankshaft should be balanced though since that's rotating indeed

For conrods and pistons the only rule is "lighter is better" ... well for single cylinder engines;
for multiple cylinders another rule applies "all must(should) be identical"
but not of specific weight.. again.. no rotating mass.
So as long as the two conrods are of equal weight you're good.

'sid

 

[Poboy kartman]

weight of the con rod is not too important since it's no rotating mass (only reciprocating)
the crankshaft should be balanced though since that's rotating indeed

For conrods and pistons the only rule is "lighter is better" ... well for single cylinder engines;
for multiple cylinders another rule applies "all must(should) be identical"
but not of specific weight.. again.. no rotating mass.
So as long as the two conrods are of equal weight you're good.

'sid

Well......not exactly....when calculating bobweight and balancing multi-cylinder engines, conrod weights are an intergral part of the equation, and must not only be balanced to each other, but on each end to each other...(and if possible, of a weight that fits into the target bobweight....[to minimize crankshaft modification]).

The conrod is the one part of the system that is neither totally reciprocating nor rotating, but a mixture of the two....so the big end and crank bearings are figured in the equation as rotating, while the small ends and wrist pins are reciprocating....

That being said, on a small, single cylinder engine, weight and balance is not as critical....