The one engine with the cast in venturi is the "custom" .40 stunt that Aldrich allegedly had some input on isn't it?? I have a few examples but have never run them. I think I have read on here that they run well with a nice sound, but are not a real power house. Back in my early years guys were putting ST.46's in them, but that engine choice doesn't help you much. If you could find one that some one had changed out the piston and liner for one of Brian Gardner's set ups, and it was a later one with muffler ears, that would put you in the ball park. I have seen guys drop ST G.51's in them also if they came out a bit heavy. I have been wanting to build another one with just that in it since I saw the first one like that. A G-.51 with a tongue muffler isn't all that heavy. There are worse put there. As far as the K&B.40, they seem to be tricky and you don't see a lot of guys running them n anything, primarily I think because they are heavy, big case engines. Even when the came out with a C/L specific ABC version, they didn't overwhelm the market, and I have yet to see one of those in a model also. The other Fox in the photo, is it marked that it's a .40?? When they came out with the .36X for the combat guys, Duke wanted to tap the R/C market, so in order to do that quickly, the first ones simply had the carb glued in with epoxy!! I actually know the guy that worked on that project!! He hangs out on the combat forum here some times, Andre Ming. The late Lew Woolard did a good job with setting up the big case Fox .40s. I saw one of those fly a Jecto Shark build from the Jetco Kit at VSC one of the first times I went, and that was my introduction to Mr. Woolard!! I have flown Brodak .40s enough to know that I don't think I would put one in a Chipmunk. They can fly a 45 to 50 ounce profile model, but a draggy model like the Chipmunk, I just don't know Just finding something new out of the box will be difficult, with nothing in production right now, even the Brodak .40.
Type at you later,
Dan McEntee