check out this small engine im building!

[vwdmc16]

For my last semester in high school im taking a metal shop (yeah i'm 18 if you guys didn't know or care) and since i took one in freshman year, i wanted to build something cool. Now most other students made some dumb things like BBQ pits and crap but i wanted to try something a little more difficult. Like build an engine. yeah an engine. not assembling or putting an engine together but making and engine from scratch...oh yeah with only simple power and hand tools (no lathes, molds, computer controlled crap either) MIG welders, Demel, and of course grinders are allowed
we have a crappy TIG but i'm not good enough with that.

so being the most skilled welder (my teacher said i taught him a few things as well) my teacher was only a little leary when i told him what I wanted to make. so i set out with my main rule or using only simple tools and so far it's gone well. luckily i found a pipe that fit inside another with very close tolerances (less than 1/64th") so off i went and using only flat plate, soild rod, tubing, nuts and bolts, and bronze bushings. now i considered making my own simple nuts and bolts, carb, ignition (coil and battery made of lemons) but i'd run out of time.
so heres some pictures of it:

Now all this will be mounted on a metal platform the has the battery, coil, and fuel tank( i still don't have a flywheel though, any ideas for a 1.5-2lbs wheel thats less that 4" dia. with a 1/2" center?)

Heres a small(i don't know why) exploded view the show all the simple parts of this 2 stroke beauty, the case comes apart in 2 pieces for assembly and repair, and the cylinder will be detachable


the heads not bolted on tight and the head gasket isn't in :wink:



the port on top is the exhasut port but i'll probably make it smaller for more exhaust velocity and make a simple muffler, the smaller port that goes into the case is the intake port

[vwdmc16]

the carb isn't secured yet but will utilize a simple reed valve

[vwdmc16]

[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