ArloRogers

My Feedback: (1)

The crank mod is sweat but I have never ran a 4-stroke single cylinder before, will it idle low enough?

Maj_Overdrive

My Feedback: (11)

I've always wanted to swap a 4 stroke into a truck. Yes it will idle low enough, the problem is it doesn't rev as high. Most 4 strokes don't rev beyond 12,000-13,000 rpm where as a nitro is somewhere between 35,000 and about 38,000rpm. To maintain the same top speed the gearing would have to be drastically altered. One solution someone came up with for putting a .70 4 stroke in a LST was to make an engine mount that had a jack shaft built into it. This jackshaft was an overdrive, increasing the rpm of the engine before it reached the stock spur gear on the transmission. If I ever did it I'd go this route or switch to a center differential style transmission but with a spool from something like the Ofna GTP. On that spool you could put a much smaller spur gear, much smaller than you could probably put on a transmission. The other issue you'd have on a TMaxx is space, you'd definitely need a longer big block chassis, possibly longer to fit the engine.

O.S. did make some 4 strokes specifically for putting into ground vehicles. These engines had revised camshafts and stiffer valve springs so that they would rev higher. The .26 sized one rev'd to 26,000 I believe. There was also a .40 size engine as well. These engines are long since discontinued and their parts are hard to come by. But a .40sc camshaft and valvesprings does fit some newer .56's (not the current .56) if you can find those parts. There's also issues with getting them to run right and not too hot. A fan of some kind is usually needed as well as possibly pumps, check valves and other stuff on the fuel side. Definitely not a bolt on.

Maxximize

I remember those O.S. 4 stroke land engines. I only ever saw two of them in person. One .40 powered T Maxx at the track one Saturday fun running with the rest of us, and one .40 T Maxx shelf queen owned by the owner of the LHS that was always on display there. I don't remember how they were cooled, but I do remember the clutch bell and spur gear were radically different in size from standard set ups available at the time. It looked like they had used big block gearing, but the one at the track honestly looked like it was near 1:1 gearing. Me and my buddies had guessed that the spur and maybe even the clutch bell were actually custom machined parts. They looked like stainless steel, as did the flywheel. Anyways, the engine really didn't perform all that well on the track. It was kind of slow on the top end, but it did get to speed quickly. It was slightly slower in lap times than my T Maxx at the time, which was powered by a Team Orion Wasp .18 Max engine. In the nearby mud pit was where it slaughtered all of our trucks though! The torque was off the charts on that thing, I remember it pulling wheelies in the slippery muck even. In the rough terrain, mine couldn't even smell it's exhaust, and mine was the fastest of the 3 Maxx trucks me and my buddies had there. It was the best bashing Maxx I'd ever seen, it did the same speeds on flat ground as it did in 3 inch deep muck! I always wanted to build one, but never got up the funds to do it.

The guy who owned it had explained the stuff he did to make it all work, but being about 12 years or so ago I can't remember any of what he said. Anyways, Here is a link I remember finding a few years ago on the subject. It outlines what the guy had to do to get this to work well, and also mentions some parts he needed to fit it all together finished with a video of it running. Those things sound so damn cool! That would be an awesome project indeed! With a fair amount of time patience, and ingenuity, anything can be built