check out this small engine im building!

[vwdmc16]

this is the piston with a ring in it, the groove was painstakingly cut on a power bandsaw and had to be done twice cause the first was too sloppy

Heres the ring and carb from a Thunder Tiger model airplane engine


heres the engine mine is modeled after (same stroke, bore, carb, etc) however mine will run on gas not nitro it's 15ccs and rated at 1.5 hp


So what do you think? i know it looks if'y but we'll see how and if it runs.

so give me any questions, comments, tips, ideas or whatever you have for me!

Vwdmc16

[super vw]

So since your modeling your motor after a nitro methanal/ethanal glow plug ignition design... how are you planing on ignighting gas? with a spark plug it looks like? how are you controling the spark?
and is this going to be a 2 or 4 cycle engine? (you have no valvetrain... so im assuming 2)

im interested to see it done!

Jonathan

[CLKWRK]

Hello,

This is true, the glow engine you are copying uses a glow plug with a thin wire element in it that glows, For your spark plug to work it will have to fire continually, or at the right moment. I suppose you could put a "cam" or a bead of weld somewhere on the flywheel that triggers a microswitch at the right place wich grounds a coil to fire the spark.

Anyways that looks like a fun project, wish i had the time

Bry

[vwdmc16]

you guys are exactly correct, it its a 2 stroke (i couldn't make valve train parts that small)
the igniton is a conventional make and break with a 12v coil from an old suzuki moped and a lawnmower 12v battery, i'll use an old points from my VW and i will have a dimple on the flywheel as soon as i find a sutable one

Any ideas on a flywheel?

[super vw]

hmmmm.....ok
You could use a VW alternator pully lol! might not be heavy enough? the heavier it is the easier it will be to keep it running. but i dont think you want it to heavy or starting the cycle could be harder.

[vwdmc16]

hey i got an old generator pulley, that may work

however there is a point where the weight is too much and the heavy weight will dampen the torque impulse and the motor will stall so maybe a 1/2 -3/4lb flywheel would be best

[super vw]

Research the weight of the Thundertiger (or any engine of the same displacment) flywheel. That may give you a direction on how much weight and diamater you may need... only thing is that your using all steel (heavy) internal componets, and i think that thunder tiger (as with most engines) use mostly aluminum internal componets (lightweight) so that may also change things with your selection.

I use to do a lot of 1/8 scale nitro on and off road racing when i was growing up. and the flywheel weight changes a lot of things... but i think for your purpose its not super critical as your not going to be using the motor for any real locomotion of an object?