Hi Paul,



Today I inspected a turbine jet Rotorway 162F mainly because of the Rotorhead that I wanted some measurement from

The owner informed me he had purchased a kit from KISS Aviation for the Turbine

They provide a reduction gearbox at the back of the turbine reducing from some 20,000 rpm

The engine produces 140 hp (I think)

The reduction box is quite tiny, as can be seen in the photographs

The owner informed me that the 90Degree drive is a differential from some sort of race car which was one of my original idea’s  to use a 9” Ford

the engineer I spoke with about my idea is the guy who designed the
D2 which didn’t fly.he said wasn’t a good idea and wanted me to use his Planetary design

However a 9” Ford diff crown wheel and pinion which produces many
ratios, there is a place in USA, Strange Engineering   Morton Grove,
Illinois

They are suppliers of transmission components and can supply a lightweight centre ( picture sent) for the 9” Ford Diff about
$1500.00

The diff for the EXEC cost $35,000.00 I am wondering if anyone can identify the differential. Pascal told me it came out of some sort of race car but

Didn’t know exactly what.

Any comments once again would be appreciated, any better solutions would be tremendously helpful such

something already manufactured.



This is website for Turbine Kit

Turbine Helicopter Project - JetExec
<http://www.jetproject.rdswebs.com/page2.htm
<http://www.jetproject.rdswebs.com/page2.htm

/www.jetproject.rdswebs.com/page2.htm/
<http://www.jetproject.rdswebs.com/page2.htm/

View shared post <https://www.google.com.au/

I must say that the support has been excellent from *K.I.S.S.
Aviation*. When a problem or weakness is identified, Dave Domanske is immediately finding and *...*



Regards George  Crooks from Aus


That looks like a sprint car or midget race car rear end. A midget race car  is just a smaller sprint car. Sprint cars have some other parts that would work like hollow axle shafts.

http://en.wikipedia.org/wiki/Sprint_car_racing
<http://en.wikipedia.org/wiki/Sprint_car_racing

Please don't send doc file pictures George. Save them as jpgs. You can export them from doc files. I had to do it.

Paul Lamar

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http://www.rotaryeng.net You Tube http://tinyurl.com/beqqxas Copyright 1998-2014 All world wide rights reserved.


The left photo is of an Al Ford 9¨ carrier. Strong and well developed. Lots of ratios available. The problem with these is the gear cut takes more HP to turn them. That is the difference compared to the Ford8.8 diffs.

The sprint car racing diff is a nice piece, but expensive due to limited market. It also has the quick change ability built in which you do not need and it adds weight.

Available from FRPP is the diff housing from the Ford IRS system.
They do not recommend more gear than 3.27 but that is for cars. Guys running 3.73 or 4.10 will have a tendency to let her rip now and then which puts a high shock load on things. In the helicopter it is a high but continuous load. It is fairly inexpensive and a 4.3 ratio should be able to be installed. It should also be fairly simple to devise a cap for the lower end when turned on its side so oil can not leak out past a flooded seal. Then with a primary 3.17 planetary reduction made from the Ford planetary parts. will get you 13.6 reduction which is close to your original 14:1. An over run or one way sprag clutch will look after engine out if required to auto rotate. Cost on this should be fairly reasonable compared to other options.

Just looked at the FRPP website and do not see the IRS housing any more. Should be able to get from the parts dept as they were used in the Mustang Cobra and Lincoln. Recyclers have complete IRS for about $1500. You may be able to part out just the diff assy. Found the FRPP housing on the Summit web page

Heidts also makes an IRS Al housing to use the 9¨ diff parts. Al pumpkins available also.

Then there is the Jaguar IRS which are readily available.

Dale Davies


Paul and friends,

How do we know the rated rpm and torque for the Ford planetary system?
Do we know the material used for making them?  It would be rather hard to decide on which gear fits which application without such data.

Gordon Gao

No I do not. All I know is it it used in the Ford power stroke diesel truck.
650 ft pounds of torque.

Paul Lamar




Hello all,

Many thanks for all your suggestions and help I am sure it will all be of value to me shortly

The actual torque of my helicopter is being calculated this weekend and the greatest torque will be

At full cyclic (so I have been informed), all will be taken into consideration, however if the sprint car box has been used in the

Jet Exec Kit then it is possible to find something already manufactured for my Scorpion Mazda 200hp Turbo.

The only thing I would look for would be a pinion which is central to the shaft(axel/spool)

If anyone knows of something I would be very grateful.


Many Thanks

George  Crooks from Aus

IMHO the sprint car stuff is OK for a piston engine as generally
they are much lower RPM. In the range of 2700 to 5000.

For a rotary powered helicopter it is hard to beat a 20:1 worm gear as we are talking 7500 to 8000 rotary RPM to get a decent power to weight ratio.

Most turbine engines come with built in planetary reductions
so the out put is n the prop RPM range. In that case a sprint car rear end
would be useful.

If you want a rotary powered helicopter that out performs
the common piston engine helicopter take advantage of the high power to
weight ratio, high RPM of the Mazda rotary engine. It will
beat the turbine helicopter hands down on lower fuel burn.

Paul Lamar