As I write this I have Fox .46 ABC running on Davis ABC mx with a Taipan 10.5x8 prop. The engine has 10 minutes total run time on Fox 5% glow fuel with 20% castor. So far it turns the Taipan at 11,655 rpm. I am going to finish a 16oz tank of Davis ABC mix which will take close to an hour and refill and get some more numbers and pitchers.

if it helps any for a reference, here is my Fox .45 wart engine running as a diesel. I was using DDD fuel and a Master Airscrew 12x8 prop on it and I got about 9,400 RPMs. That should improve over time as the engine is new and still being run in of course. I figured the old timey dinky Fox muffler is fine on a diesel engine due to its unique combustion processes.

[youtube]http://www.youtube.com/watch?v=WTp3Lkr9pSw[/youtube]

Thanks Earl, I got about a 120 rpm improvement over the first run. 11,777 to be exact. It runs best with the EZJust carb open about 85%, if I open it further the engine leans and slows, if I richen it a couple of clicks so it does not lean out and slow down it still runs the same rpm, so this falls right into what Mr. Davis says is a perfect set up job.

Please note exhaust, no gasket and no leak, not even a dribble.

That is interesting, My old/new .45 with the new carb will let me go WOT.
I had ran the engine without muffler pressure even. I have added a fitting to the muffler but I wasn't planning on fireing up the engine again until I mounted it in a airplane.

Its a shame that the Fox .46 ABC gets lost in the shuffle, it is readily available, totally reliable and unbelievably tough. On 5% nitro fuel it will turn a 10x6 at about 14,100, I never could quite get the 14,400 Fox claims. I long for one of those new TN carbs but circumstances no allow.

Hi David

The MVVS quiet muffler looks good on the Fox 46. Were any modifications necessary to ensure a good fit?

Thanks Derek, no mods, the bolt holes in the Fox are ever so slightly closer together than the holes in the muffler but they run down with only minor resistance. The 3255 fits the larger Fox .60 and .74 the same way.When running the square MVVS DustBin on the .74 Diesel conversion it has a really neat sound.

Yeah I needed to touch up the holes on a MVVS muffler a little and elongate them slightly on the inside as the FOX engine's holes are about 1/2mm closer together. Depending on the muffler and how large the holes are, you may or may not have to oval the holes slightly. I put a Bison in-cowl muffler on my Fox 45 powered Japanese Zero plane, and I had to elongate the holes on the inside slightly to get the screws to go in. But another engine, one of my .60 engines, the MVVS muffler fit it just fine as is.

I am not sure the carb would have made a difference. it is interesting you couldn't go WOT. it might be the smaller prop you used versus me running a larger prop.

OK, I'm adding this post here since this involves a Fox .46. I dug into my junk parts bin and came up with a useable Fox .50 cylinder, piston and ring. I have a well used .46 ABC with a slightly loose rear bearing, I slid the .50 cylinder into the .46 block while rotating the cylinder so the ring would gently adjust its self and go in. And of course I went against all logic and put a Fox Quiet Muffler on it. I used the same carb as on the .46 above since it was already set up. I first ran a MA K 12x5 for an easy load and good flywheel effect then changed to the Taipan 11x7. It holds 11,000 plus rock steady as long as you want. The Davis head is quite old and well used but that doesn't matter at all. On this one I could run the carb at full open. This set up runs easy and smooth, idle is for as long as you'd like with no burble from cooling off. Atta Boy Dave, and I just broke my own arm.[8D]

Hi Dave,
Is it a normal thing to use a 50 piston/liner in a 46 block?

Imean it obviously fits but was it intended by the factory that way?

And do you have any wieghts on these engines mate?

Cheers and well done.

Recyled flyer a few years ago Fox made up a 50 for me quite sure all the did was put in a 50 liner, piston, rod the same?? I do not know ,you could see the original size stamp on the block was ground off and restamped 50 martin
quite sure it was a 46 case martin

The .46 is the .50 block with a brass/ABC sleeve in it and .46 stamped on it, the brass sleeve like most ABC sleeves is pretty thick so the .46 weighs more than the .50. The .50 is the lightest .50 being even lighter than a Webra .50.

Picture #1 is Fox .50 #2 is Webra .50. I am involved with the motorcycle display at the Richmond County fair for the next four days so will be very busy.

Dave right you are my typo 46 -50block (I.E) same martin

Thanks Martin, for several years I wasn't convinced that the EZJust carb would work well on a Diesel conversion but it is very linear with no rich bulge in the midrange.