Would a long stroke glow engine work very well?

[Kaleb]

I'm contemplating building a small glow engine a bit under 2cc as a next project. I am going to use this carby on it: http://www.ebay.com.au/itm/Free-Ship-Sale-NEW-RC-Carburetor-s592579-ASP-GX-12-nitro-engine-/270874371383?pt=AU_Toys_Hobbies_Radio_Controlled_Vehicles&hash=item3f115ee537

The engine it's for has a 13.8mm bore and a 13mm stroke. However I don't really want the ultra high speed performance typical of these, and I'm going to need good compression, so I'm thinking of using a smaller bore and a longer stroke since I believe this will make it easier to get the required compression, and possibly make the engine give its power at lower speeds with more torque. Is this a good idea or should I stick to the dimensions used in the commercial engine?

 

[Lakc]

Longer stroke means more friction, same for the higher compression. Thats fine as long as you have the mass in the budget to keep her spinning. Assuming your staying two stroke, the port timing will likely need to be radically different from a high rpm screamer.

 

[mu38&Bg#]

You can build whatever you like for bore and stroke. It is true that smaller bores have smaller leakage area, but are also more critical on fit. I'd go as much as 20% over on stroke if you really think it will make a difference, it really won't. One thing you should know is that if that carb is made for a 2cc that turns 30+kRPM, it will not work so well for engine engine that turns only 10k. It will be made to flow much more air than your engine and this may result in poor throttling and fuel draw.

Compression ratio of 7-8:1 in glow is average.

Greg