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Re: REFLECTOR: Engine weights
At 05:24 PM 10/13/98 -0400, Carl Hoffman wrote:
>Didn't you mean some like:
>IO-360 320.4 lbs 24.2 inches from firewall.
>I0-540 396.4 lbs 28.2 inches from firewall.
>FRANKLIN 318.4 lbs 24.4 inches from firewall.
>MAZDA 430.2 lbs 19.4 inches from firewall.
>CHEV V6 Alum block
>In other words the weight of the engine and the c.g. of the engine from
>the firewall. The empty weight of the plane depends on a lot more things
>than the weight of the engine. I think your interested on knowing the
>effect of hanging different engines on the same plane.
Yep, this is what I meant. Simon is correct in stating that weights & c.g.
vary from builder to builder, and that Velocity's way of measuring c.g. is
from the nose. However, it would be useful to know the effect of hanging
different engines on the same airplane; the point of attachment is the aft
face of the firewall.
What I should have asked for is weight and moment arm from the firewall,
where the moment arm is measured from the firewall to the c.g. of the
engine. Carl lists some interesting numbers, which I take to be bare
engine weights & moment arms. It would be useful to have similar info for
the complete engine package (with all accessories) and moment arm [yes, I
know lightweight starters; one vs two mags; etc., all make a difference!].
Using Carl's info for the bare engines, and using the IO-360 as base case,
the differences in weight and moment arm are:
MOMENT ARM DIFFERENCE DIFFERENCE IN
lb-in IN WT, lbs MOMENT ARM, lb-in
IO-360 7754 0
IO-540 11178 +76 + 3425
Franklin 7769 - 2 + 15
Mazda 8346 +110 + 592
There is little difference between the Franklin and the IO-360, but a big
difference going to the IO-540.
I "assume" Mazda means the 3-rotor (20B?) engine??
Any othere input?