Hello everybody,

First, let me briefly introduce myself.
My name is Cyril Wichers, I'm from the Netherlands and my hobby is RC tractorpulling.
During the last 15 years or so, I've built several pullers, powered by ic engines, ranging from single .21 buggy engines to twin .91 ducted fan engines. I also did some experimental stuff, like converting a nitro engine to run on diesel, converting a 2.5 Cu/In 2-cilinder weedeater engine to run on methanol and joining two OS .30 Wankel engines, to form a single unit.

Now I'm planning a new project, involving big gas engines.
What I would like to do is build a puller powered by the biggest and most powerful gas engine I can possibly fit in it.
In the end, it should look something like this:


I'm limited to a max weight of 5.5Kg for the complete puller, so the max weight for the engine (including ignition and exhaust) would be about 3Kg (96.5 ounces)
Maximum width is 320mm (12.5 In) Maximum lenght is 426mm (16.7 In) measured from the centre of the rear axle to the front of the puller. This allready implies that using tuned pipes is not an option. I'm even considering running open exhausts (or just headers) to save weight.

I'm thinking of using one of these three engines: BME 115, 3W 106, DA 100 (these also fit in my engine-budget, I'm thinking of spending around 1000-1200 Euro's (1350 - 1600 Dollars)
The question is, which engine do you think will fit my needs best? Maybe there other alternatives that Im not aware of?

Thanks in advance,
Cyril