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Denis Martineau,    Quebec City Canada       12/16/2007

CO2 (or compressed air) Mini V-Twin

This is the very first engine I built ever ... not knowing that smaller does not mean easier! Only is it cheaper on material when you make a mistake.

The design is from our well known webmaster,  David Kerzel.

This engines has a bore and stroke of 0.250 in. The nice thing with it is that it is very eye catching and small enough to carry-on in our pocket, thus allowing you to show people what model engineering can be.

It always draws some attention from people when you show it. Just the sound it makes by flipping it manually is very appealing.

Being my first engine and of such small dimensions, quite a few mistake were done but still, the design was forgiving enough that it ran almost the first time I supplied air to it. At 120 psi, it spins like crazy, just like a compressed air drill.


The design overview from the plans.


Amazing how a 4-40 screw can look big here!                                            The head screws are 0-80 cap screws. A very small tap to use ... easy to break too.


                                                     The ball seat in the head allow air to come in when piston reaches TDC.



The ball seat is press fitted into the head. Pin on top of piston lifts the ball at TDC and lets air flow in.




Once more, some good words have to go to our webmaster David for his time to draw this engine and share with us. 

Plans are available from this link: clicking here.

Someday, I'll make it stand on a fancy wood base. My plan was to make the base big enough to be able to hide a 4000 psi bicycle pump CO2 cartridge to supply the engine and make it run.


Copyright 2007,  Florida Association of Model Engineers and engine builder as noted above, All rights reserved.