Rotax 912 engine mount for Avid Flyer

[dholly 718]

Ok, I need to fit a cowl to keep my project moving. Can anyone help with these questions?

Here's what I know... At one time Avid offered a dynafocal style ring mount for Rotax 912, which is shown in the following 1992 drawing.

I have heard through the rumor mill, sometime in mid-1990's when Reiner Hoffman of Stratus Subaru was designing an engine mount for use with his engine on the Avid, he may have also re-designed the 912 ring mount for Avid. Here's a post from Steve Winder in the Yahoo Group archives that would seem to support the theory:

The 912 is probably the Best engine option ever fitted to the Avid apart from the cost. Whilst at Avid in 1994-1996 I worked very closely with the German Avid dealer (sold over 100 into Germany mostly 912's) to provide a German "FAA" acceptable 912 installation--- the Standard Avid installation was not. We mounted the Oil Tank on the firewall just in front of the passenger and moved the Carb Filter box over to the Pilot side... Was a very elegant solution--- we also did some work on using the Standard 912 Exhaust / Muffler-- it does Just fit-and more importantly it does need an oil cooler in the Avid. We at Airdale are also looking at using the Standard 912 Mounting ring rather than the Avid type/Old Kitfox type which needed most of the accessories removing for installation and the Cast Aluminum Water pump elbow heating and bending-- by builder, to clear the engine frame--- invariably it got broke and another one was required. You then refitted All the accessories back again!! The Rotax ring just bolts straight to the engine and then the ring to a mount--- Installation of the 912 is quite costly and complicated/busy as lots of it crammed into a small place... Cowling may need to be extended about 1"-2" as 912 sits further forward on the fuselage... I'm sure others on the list will comment---

Hope this helps,

Regards,

Steve at Airdale.

Here is the standard Rotax engine mounting ring:

So...

Q1.) If you have, had or ever saw a 912 install in an Avid, was it the original Avid/Old Kitfox type mount (shown in the 1992 drawing from Avid, at top), or a new firewall mount that accepts the standard Rotax engine mounting ring?

Q2.) Does anyone have the pertinent measures of either of these 912 Avid mount options ie., back of prop flange to firewall, thrust line, offset etc.?

Q3.) Does anyone have the pertinent measures of the 912 KITFOX 5-6 mount options (to confirm a KF 5-6 smooth cowl for 912 is long enough and thrust line compatible for use on my Avid+, as width, windshield curve and rake work good)?

Thanks, any info appreciated.

Edited 2 Jun 2011 by dholly

[Av8r3400 1179]

Doug--

Q1 My friend Dave is building his Avid/Kitfox hybrid. He's using the Avid 912 mount from Airdale. It is almost the same as my Kitfox IV mounts: A dynafocal ring with four arms coming off which bolt to the motor. (your first photo will not download)

Q2 Got nothing for you, now. Maybe I can get Dave to take some measurements for you, or I can give you his email and you can contact him directly...

Q3 Nada.

[dholly 718]

Thanks Larry. I loaded the pic fine but resized as it was too large. Maybe that will help if you try again. In any event, it sounds like Dave has the 'old' version as shown in the pic with the ring on the portion that bolts to the firewall as opposed to the ring on the engine. Do you happen to know if his mount required that any tubes be bent for exhaust clearance?

[Av8r3400 1179]

The "Airdale" mount is similar but not exactly the same as that. That is the current mount that Brett is supplying. The "ring" type mount in your second pic would never work in an Avid. It won't fit.

Dave is a fabricator extraordinaire and did rework parts of the mount to fit his application. He is building his own exhaust system.

[dholly 718]

Well at this point I may have a local guy make me a one-off mount, something I've tried to avoid because it means I have to go buy an engine. The one I'm most likely to copy is used in the Aerotrek. Their 912 install is very compact and clean looking, and keeps the radiators and oil cooler under cowl. I called Bob Rollison about purchasing a cowl almost two years ago and he refused to sell even one bolt to a non-owner. Told him I'd sign whatever liability release his corporate attorneys provided but he just did the big FU flip-off. Man, this "potential liability" shit is taken to such an extreme by some people, I doubt anyone could pry an engine mount or other FWF parts from his cold, dead hands.