Paul

 What has been the discussion so far concerning air assisted direct fuel
 injection stratified charge for the Wankel.

 It would seem that the wide circumferential depression of the rotor would
 allow for optimizing the injection timing and that less loss would occur
 from sealing than that of a spark plug with proper tip configuration for
 the
 air-fuel injector nozzle.

 This would seem to have the optimize the possibilities of a true
 stratified
 charge with no fuel on the walls of the Wankel to optimize the BSFC.

 The injector would possible be of Australian Orbital Tech Group type to
be
 used in the GM XV-8 Opel Signum 2011. Now since the German
 Government owns Opel this is probably in question. Have you heard is GM
 planning to use the XV-8 in any US car or truck

 Norm

 To my knowledge3dge nobody has tried that in a rotary.
 The Wankel is naturally stratified charge as the rich mixture
 is thrown out towards the plugs due to the rotating combustion
 chamber. That is probably why it will run a couple of hundred
 degrees F lean of peak. Mixture ratios of 20:1 air fuel.

 Paul Lamar

 Paul and Norm,

 I investigated the Orbital technology, and it would be workable. The
 biggest
 problem is the Orbital people only want to sell to big OEM operations
 under
 license. The minimum that it would cost you to get started is 25K. They
 flatly refused to allow any discount to small engineering or prototype
 shops. The only way to get what you need otherwise is to get the parts
 from
 a Mercury or other 2 cycle outboard. The trouble is you don't know if the
 injectors are going to be close on volume, so you couldn't use the
Mercury
 control box you would have to use Tracy's or SDS or Megasquirt. The last
 item is that you need to run an air pump to feed the injectors which is
 engine driven. The cool thing is that Mecury has paired the air pump with
 the
 oil injection pump and you could use that to provide the apex seal oil
 without pre-mixing. I was going to do this until I priced some of the
 Mercury parts otc. The prices on replacement parts are so jacked up that
 it
 wasn't worth it. I do look for available outboards at the marine shops
 occaisionally, but these are the high end of the model line and you don't
 see outboards crashed or blown up as often as cars, making parts harder
to
 come by. I believe that it will be easier to get the direct injection off
 of
 a newer Audi or VW wreck running the Siemens system since there will
 be thousands more of them on the road.

 Bill Jepson

 Don't get your hopes up on direct injection. Getting that to work let
 alone work in such a way that it improves the BSFC would take many
 thousands of dollars worth of R&D. You can't just install direct
 injection and expect it to pay off. I know what Porsche went through
 and it was not cheap. I was there when they presented the results.
Besides
 that they were lucky to get a 5% improvement.

 Paul Lamar

 Paul,
 Provided I could make the through housing port without trouble. (And
 thatIS
 a big question.) I would be happy to get a 2% improvement. The biggest
 advantage would be no concerns about how to orient the injectors in the
 tubes or the throttle body. Followed by the ability to change the tubes
to
 test tuning with minimal trouble. Something that should be mentioned for
 the
 Orbital system is that it is a maximum 2 bar system. You can inject after
 the
 intake port closes, but not near full compression. The Siemens system is
 designed to inject right up to the point of ignition.
 Bill Jepson

 Any high pressure air pump is going to take some HP at the volume
 required. It takes really high pressure to vaporise the fuel to the
 point the mixture homogeneously better than injecting at the start
 of the runners. 2 bar is not going to cut it. Simple two cycle engines
 get the fuel/air mix in strange ways. It comes up from the crankcase
 so any fuel injection might be better.

 You may wind up with worse BSFC rather than better in the rotary.

 Not a shade tree job.

 Here are some ideas that address a specific rotary problem
 using high pressure air injection.
 http://www.rotaryeng.net/Strat-charge.html


 Paul Lamar

Gents,

Next issue of E-Experimenter will have a reprinting of the Hirth Heavy
Fuel
DI system for UAV's using Orbital's Air-Assisted Injectors which
originally
appeared in Contact! (I wrote the story). Note, their are many SAE type
papers on OE's technology. Gaseous fuels can be run through the gaseous
side, as well as E85 work being done or Brazil. However, OE does not want
Gen-Av exposure (i.e. liability) at this time.

Best Regards,
Anthony

Hey Anthony how about writing a couple of articles about the rotary?
I can help and give you permission on anything you see on here or need.

Paul Lamar

Paul,

Thanks for the offer perhaps in the near future. I think Pat Panzera has
done an all Rotary Issue or two, It maybe time to revisit Wankels.

My Best,
Anthony