Guys,

What is the diameter of a 12lb thrust motor like the Wren 54mm or Simjet 1200 etc.

Thanks,
Vin...

Hi Vin

Hmmm getting cold up this way now and I am taking a break from glueing and painting. I show.....3.5" diameter on the RAM 500 and the PST 600 should be about the same.

My wren 54 measures 89.2 mm in diameter

Regards

Tom Watson
Sydney Australia

Thanks guys.

Dean, if you want a real break from the cold, come on down to the AJR!!!

Vin...

Hi Vin

The 1200 is 3.5" in diameter.

Ed

Too big of diameter.

3" front taper to 2.5" rear.

This is the best performance diameter for Ram 500.


Maybe going to AZJ.

Brg,
Tam

Oops

Maybe I misread the post? Vin did you want to know engine diameter? Then it is 3.5 " for the SimJet, RAM and PST. The exhaust tube on the other hand should be around 21 mm if used as a straight non tapered design. Tam probably has done the most testing here and his measurements are probably even more efficient. I think BVMs F86 pipe etc is roughly that diameter.

sorry boot that

AHHHHH........I think its time to go to bed. Geeszzzz you'd think I did not know my metric from standard measurements!!!!! My elementary school teachers would be turning in their graves right now. Lets try this again.....at RAM in early 2001 a number of tests were done using different diameter exhaust ducts. The most efficient ( lowest temp for greatest thrust output ) was found to be about 2 1/4 - 2 1/2 inch diameter or......ready for this ( drum role please 55 - 60 mm )

O.K. I am done for the day....goodnite

Dean,
Now you just make me reallized Vin question go both way.
I read his subjet heading before his question.
But if I read his question first. My answer just like your.

If your a** getting freeze. Fire up those turbine heater.

Tam

Goodnight Dean,
My wife just calling me to bed.
But I got to take care the K1 smell first.

Goodnight,
Tam