The current layout obviously works and has been crash tested with good results. The engine remained attached to the fuselage and in front rather than being folded under. Well, for that particular crash anyway.

 

I wonder who got the salvage?

 

However, if you plan to start from scratch, you have an opportunity to outperform Mistral. The most recent Mistral is not the first, although the name may have been different. I met Frances at the engine tent at Sun&Fun years ago. He had the reduction unit with him. He was excited to meet somebody who knew stuff about rotary engines. Once they had relearned all about rotaries, and had thousands of dyno hours built up, they had quite a package assembled. But the certified nut is hard to crack, and I think both versions of the company died trying.

 

Perhaps building up a collection of products based on the rotary installation rather than a complete unit that was about the cost of a zero time Lycoming or Continental. You have to be able to point out some sort of advantage over the conventional engines. People who put car engines in airplanes do it primarily for cost reasons.

 

Having an installation testing here was another thing that escaped me.

One year they had the plane flying, but the oil temps went up so high so fast that it could not fly to Lakeland From Embry Riddle. So I made some suggestions. Like don't use multi grade anything. Don't use multi grade aircraft oils. Full of plastic and foams like crazy. That fills it with air, and then the coolers stop working. Use straight weight car oil. Its a car engine. Racing oils have lots of anti foaming additives lots of anti scuff compounds and very high film strengths. Synthetics even better.

 

Later they built their own oil pump housings and pickups. With suction feeds from both ends like the FD pumps. No bug screen. The Baffle had the bug screen in the drain back hole. 

 

At a constant 5,500 or 6,000 RPM, the bug screen and sharp ended pickup tube add to foaming and poor suction side performance.

 

Bigger coolers of course. You calculate the exact cooler size you need then buy two of them. If you buy one, later you will need another.

 

The other factor I saw was that the support for a governor invites the addition of a 60 pound constant speed prop, a long way out from the mount. We don't need the engine falling off in a hard pull up, or really bad bounce on landing. There is an established design factor for that. About 5 Gs maybe. So, here is a chance to improve on Mistral. 

 

Adding a few holes that need to be threaded is not a deal killer. Even if you need to go to a shop and have it done. So long as the actual pieces become available to builders. An idea that escaped Mistral.

 

Lynn E. Hanover

  

 

Lynn, re: Strength of the Connection.

I remember you stating some of those points a while back. I'm wondering if, in our lower power state, these are as much a concern as they are in the racing world? It would certainly be possible to add extra parts to the install [the thickened bottom plate, or perhaps some form of a stiffener that locks the block from torque related movement front to back  { all just thoughts flashing through my brain, RHRN}. I've not heard comment about how Mistral addressed this [or if it was a concern of theirs?].

Kelly, do you know of any additional connection points [dowels or pins etc] that were needed for the install of a Mistral housing? 

It certainly is not my first 'pick' to have a mounting housing which needs modifications to a short block, to allow it to be installed.


Jarrett Johnson
www.innovention-tech.com