290G Question / Help

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I have a converted 290G and would like to add an alternator. I have the
alternator the correct old style case mounting bracket, pulley, etc. My
problem is that the 290G does not appear to have a machined boss for
attaching the tensioning. I have seen photos of several 290G's with
alternators so I know this can be done (just haven't seen a picture of
the tensioning arm attach point). Just need to know what most people
are doing to attach the tensioning arm to the engine block. Any help
with this would be appreciated, pictures would even be better.

Anyone out there with a converted G with an alternator/generator?

Thanks!

[Orval Fairbairn]

In article . com>,
wrote:

> I have a converted 290G and would like to add an alternator. I have the
> alternator the correct old style case mounting bracket, pulley, etc. My
> problem is that the 290G does not appear to have a machined boss for
> attaching the tensioning. I have seen photos of several 290G's with
> alternators so I know this can be done (just haven't seen a picture of
> the tensioning arm attach point). Just need to know what most people
> are doing to attach the tensioning arm to the engine block. Any help
> with this would be appreciated, pictures would even be better.
>
> Anyone out there with a converted G with an alternator/generator?
>
> Thanks!

Doesn't the O-290G have a boss on the accessory case for a generator? My
O-435 does, and it is the same vintage as the O-290.

If the O-290G has a generator boss, you can install a JASCO Skytronics
alternator, but you will need to find a P/N 60956 Adaptor Assembly,
which contains a double row ball bearing, in which P/N 60954 gear is
held by circlips.

The adaptor assembly was used on GO-435s and GO-480s, in Twin Bonanzas.

I have made drawings of the assembly, so one could, if necessary, make
one out of an aluminum billet.

If you try to mount the alternator drive gear on the end of the
alternator drive shaft, the rotating torque will fatigue the shaft and
drop the gear into the accessory case.

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I suppose I could go with an accessory mounted alternator, but I hoped
to go with an easier setup with the belt/pulley system driven at the
prop end. Much similar to O-320, O-360.

Thanks.

[Orval Fairbairn]

In article om>,
wrote:

> I suppose I could go with an accessory mounted alternator, but I hoped
> to go with an easier setup with the belt/pulley system driven at the
> prop end. Much similar to O-320, O-360.
>
> Thanks.

If you can find the adapter, the accessory-mounted alternator is far
better -- no belts to break or come loose, etc. Since the adapter takes
up all side loads, the only loads on the alternator bearings are pure
torque, so the alternator lasts longer. Mine went in in 1983 and has
lasted over 1000 hours.

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Remve "_" from email to reply to me personally.