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From: Ernest Christley <echristley@nc.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Fri, December 3, 2010 12:03:02 PM
Subject: [FlyRotary] Re: intake blower update

Greg Ward wrote:
> Hey Ernest;
> Forgive an old high Country Nail-Banger's ignorance, but what is this for? It looks like a flywheel substitute for a redrive.  Please enlighten me here.
> Greg Ward
> Lancair 20B N178RG STILL in progress
One way to make things lighter, it to make one part do multiple jobs.

I got rid of the alternator and replaced it with a Harley-Davidson generator.  No belts and pulleys with their side loads.  No heavy mounting system, or putting lumps in the cowl to accommodate them.  The stator is mounted to the back of the PSRU.  The rotor is bolted to the flywheel through this adapter plate. (Kelly, the magnets are covered by a metal shield.  Makes it real easy to clean out the stray crap that magnets seem to like to pick up.)

Now, we have a plate sandwiched between the engine and the back of the PSRU mounting plate spinning at 6000 RPM during cruise speed.  How much of a stretch would it be to surround the space between the mount plate and engine with a shield, put blower blades on the plate, and then baffle the results into the intake?  Not a lot of boost is expected, only enough for 10 to 20Hp, but what is available is cheap, easy, and no-maintenance (no intercooler, blow-off valves, by-pass valves, extra plumbing, etc).

Using my calibrated left bicep, the plate weighs about 3lbs, give or take a couple (I didn't say it was a WELL calibrated left bicep).  The shield forming the blower housing probably weighs a pound or two (give or take a pound or two 8*).  The adapter plate is replacing an alternator mount, belt and pulleys, and with the help of the shield, a turbo (sorta, but not really).  I'm just happy I came across this guy moving to Texas last winter who didn't want to ship this lathe that he had just finished restoring (12x36 Craftsman), and was willing to practically give it to me for $300.  I couldn't afford to pay someone to machine this for me, as I've spent about 3 weeks on this one part.

The quandry I have now, is do I finish it completely, or do I leave the blower blades off for now so that I can know how much boost I get from the modification.  Adding them later means tearing the front of the engine apart again later.