Mailing List flyrotary@lancaironline.net Message #42549
From: George Lendich <lendich@optusnet.com.au>
Subject: Re: [FlyRotary] Re: Electric Water pumps - Interesting
Date: Mon, 28 Apr 2008 08:22:01 +1000
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Michael,
On The issue of thrust lines, I have found that with my installation ( Vision low wing composite)I can lower the thrust line 4" and it will provide a positive effect. Most Fixed undercarriages are draggy and a lower thrust line will be an advantage in this situation. Not so with retractable undercarriage - needless to say!
 
I'm trying to make my single rotor installation as simple as possible and was considering the electronic points type set-up. I would appreciate any perceived problems you might find with this approach.
George ( down under)
Kelly:
 
Yes my goal is to do a gravity fed carburetor low on the firewall. I know this means a long induction run and all associated problems to resolve there. I do already have the manifold made up for a three Mikkuni set up like Tracy's early work and Fin Lassen's set up but that means fuel pumps. My goal is a purely gravity fed system and I can do it of my nose tank. In the end it may not work but hey its called "experimental" for a reason. As for ignition I have a NOS early (pre 85) points distributor (brand new) as well as a used one of the same vintage. I also have the crank angle sensor and the taller electronic distributor. The early point distributor as you may know is much lower than the electronic one though not as low as the CAS. In building my engine mount I lowered the thrust line by an inch from design and this is as far as I dared deviate from plans being a novice at this game. This according to my figuring should have worked but by the time I was done with it all and the cowl slope I recently discovered still have to do a bump (even using the right angle boots one the plug wires of the distributor) in order to have reasonable clearance. My Falconar is an older rendition than Max Lassacher's and as such has the rounder firewall style of the older Jodels where Max's is much boxier. He of course is using Tracy's ECU so clearance is not an issue. As for alternators I am planning on 2 of the small 20 amp permanent magnet units of a Kubota tractor. These are tiny units and the Corvair fellows have had good success with them as well as the john Deere units. They weigh almost nothing and 2 of them would give me redundancy. In the end this may not work as the rotary is running much higher RPM than the Corvair fellows and switching pulley diameters to adjust dynamo speed may be impractical and it may make more sense to go with one of the smal 40 amp conventional alternators.
Back to the points distributor bit. Again from the Corvair crowd this is what they have been running with success. Though they do not run both points at the same time instead using a coil switcher to select which output to feed to the single set of plugs. The principle being that one can tell when the points are starting to fail giving you good warning to replace them and will run of quite low voltage should your electrics give up and if you wind up running of the battery you can run for quite some time this way. Electronics tend to be more sensitive to critical voltage levels. One of the other concerns is at the RPM we would, run we could see issues of points bounce and this may negate their use. The Corvair folks have been recently doing a combination of one set of points and a electronic Crane pick up unit fitted in place of the second set of points to get the best of both worlds. This may be an idea I can use and adapt one of my older style low distributors to electronic pickups.
 
In the end it all may not work, and going the proven way, ie fuel injection and Tracy's ECU as most are doing and have proven works may be the right thing to do.
 
Michael
 
 
 
 
 
----- Original Message -----
 
Michael,
     You mentioned a distributor.......Are you to be carburated and use
an early point type or electronic dist. which are very tall ?..........The
waterpump/thermostat housing can be shortened and the alternator
relocated to the side leaving the stock waterpump in place.........If
you use Tracys EC2 the tall dist. is eliminated and replaced with the
short 86-91 ignition POS (position sensor)..........FWIW


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