I just installed a MDS .48 Heli engine with a macs header, tuned for maximum rpm's & 6 ounce rave container(1 3/4 " x 6 ")in my Top Cap.The stinger is 1/4" id 2 inches long ,the engine is running a 12.25x3.75 APC prop it was getting 11,500rpms before,now its getting around 12,700,a pretty good gain.

The engine mixture is not set too lean in high or low.If i pinch fuel line while idling the engine speed will increase after a second or two so the mixture seems to be fine.The problem is that while its on the ground I can run the engine upright in a hovering position and it will run perfect with good throtle response,pick-up,and no hesitation,It is not overheating.But when i try to hover the TopCap in the air the engine will start to bog down after a few seconds and it will usuallly quit.

I have tried richening and leaning the mixture but no success.I have hit the ground pretty hard twice because of this.I cant figure it out because it has excellent power with unlimited vertical that is until I try to hover the airplane then the engine will usually act up.

I just recently figured out, that a smaller volume can, will steepen the power curve--> not good for 3D. A larger volume can will give less total power, but smooth out the curve. Tune the pipe for max rpm, then back off about 1/2". This should put you on the pipe a little earlier.

How much throttle does it require to hover the Top Cap, with your setup? Is it "on the pipe"?

Hmmmmmmm, after re-reading your post, I thought it said 3/4 x 6. 1 3/4 x 6 is pretty much std for .46 sized stuff. Try burying 1/2 the length of the stinger in the can. Try the larger 1 3/4 x 7.5 sized can, and burying the stinger. The stinger thing, I was told by some 2 stroke cycle guys, will flatten the curve---> more linear throttle.

it will take about 3/8 throtle to hover, while it lasts.

and i forgot to mention,is on the pipe,while it lasts

Yeah, you are coming off the pipe as the motor loads up.
tune it for a lower rpm.

Thanks Jayson.I will try taht,it seems very logical.
P.S.,the engine is on sale in the Scratch&dent section of Quantummodels.com(only box damage)Its only$39.99,ITS A STEAL!! The deal xpires Friday,Dec 20th

You would also try differant props. 11x4APC, 11.5x4APC, 11x5APC.

That way it will stay on the pipe more.

I have a TT46 w/ 11x4APC prop w/ moosecan. Can is 1.75 by 6.5" w/ a 1/4 outside diamter stinger that is 1.5" long. And it doesn't load up, or lean out. And linear throttle responce when the plane is level or vertical. and has throttle transition that would make a 4 stroke owner jealous. It turns 14,800RPM. I have it set to fly at 14,300. It was turning 13,200 w/ stock muffler w/ baffle removed.

I would really like to get this prop/engine combo working because it gives the most control and stability in a hover position,but if I cant get it to work i will use the 11x4 which I was using with the engine I had before,a Rossi 45(I want that engine for my Freestyle)

try building you a bigger can. That way you have more volume in can, and hopefully instead of coming on the pipe, it will run smoother. I have moosecan on a 40fp, tt46, ST45, (all have 6.5 x 1.75" can.) ST90 and none of them get on the pipe like yours do. all run smooth thru the entire throttle. find a 7" Lenght by 2" diamter can. w/ a 1/4 stinger.

instead of tearing your other moosecan apart find you some 3/4" Outside Diameter aluminum pipe. Can be found at most large hardware stores. It a closet rod. But I have a friend that paid $6.00 for 5ft.

I found mine at wall mart. I had to pay $10.00 for 42". I am using a light pole that you put on a boat. I found it in the fishing section.

Thanks for the input Gramling,I will fly the airplane tomorrow by first lenghtening the pipe more if not,I will build the bigger mousecan and try that,Thanks,I'll keep you info rmed

The mods worked out great,Thanks everybody for the help,Happy Holidays

What sized can did you end up with?

..... Also, I am curious if you guys are leaving the Mac's header full length or cutting any off.

How are you guys attaching the mousse can to the header pipe? JB Welding a short piece of 3/4 aluminum to the input side of the can and then coupling that to the header? How much total length does that give you from the front of the macs flange to the front of the mousse can??

Ernie

I ended up with the same can 1.75"x6.5",the header has to be tuned for the prop size ,I ended up cutting about 1.5" for a 12.25 3.75 APC prop,,I was getting 11600 now with the mousecan pipe about 12800 peak,I fly at 12500 or so.Throtle response its excellent. As far as attaching the mousse can just cut off about an inch of the header,and JB weld it to the can,,Then proceed to cut off 1/4" segments of the header until you dont increse rpms any more or it drops a little bit,then back off the coupler about 1/4 to 1/3 of an inch or so.Thats it!

Angelo and everyone else, thanks for all the fun mousse can information.

Another question: Are you guys supporting the moussecan at all or letting it hang from the header???

Ernie

You need to attach it to the fuselage. on my profiles I just drill a hole in the fuselage, put me a ziptie thru it, then tighten the ziptie around moosecan. I put some foam inbetween moosecan and fuselage.