Topica Loopframe_Guzzi Archive


Subject: Re: con rods

Author: GuyW

Date: Sep 15, 2004, 3:08 PM

Post ID: 1717535371



That's what I wuz afraid of....one doesn't change the stroke (and cylinder
volume) by changing the rod length. For any given stroke, a variety of rod
lengths can be (and are) used as a method of tuning the engine's power
characteristics.

In this case, given the increased stroke length, and the use of the same
rods, the piston deck height had to change (or the cylinders had to be
shimmed up with "stroker plates") to prevent the piston from popping up out
of the cylinder.

Which makes me wonder - has anyone heard of someone using stroker plates on
a Guzzi??

-Guy-


Hi Guy,

The bore on the 750 and the 850 is the same (83 mm), yet diffent pistons
are used. The stroke is increased between the 750 and the 850 (from 70
to 78 mm), but was done so by a change to the journal height on the
crankshaft.

So, Guzzi decided to change three more expensive parts (2 pistons and 1
crankshaft) instead of two less expensive parts (2 connecting rods) just
to increase the stroke.

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