I have been flying my 4*40 with a 40LA as a trainer but now I am looking for more power. I have been told good things about the Super Tigre G-51. Would this motor match nicely with this plane? A four stroke would be nice but its about 2-3 times the price of the G-51. Any comments would be appreciated. Thanks guys.

Regards,

Dion

I am not sure that putting the 51 on your 4 star is going to gain you anything. I have an OS 40 FP on mine and it is a perfect match. I might consider an OS 46, however I think that exceeds the suggested size range and once again, I do not think that you would gain much. I am assuming that you are looking for more speed? Super Tiger does make good engines, however I am an OS engine man myself. Good Luck, Dave

Thanks for your reply David. I agree that the 40 is an excellent match for that plane as I have trained on it all last year.

What I am looking for is more performance so I can start getting into aerobatics. Therefore I was just looking for more speed and power. I realize that OS makes a great engine, in fact I have nothing but including the 40LA, 61FX, and 50SX ringed for my Raptor. However I can get the ST G-51 for almost half the price of the OS 50 ringed. Do you think the it would over power the plane? I do have a Sig Hog Bipe in the hangar that is built but I haven't flown yet, with the 61 on it when I get into some real 3D.

Dion

The 4 Star isn't the best choice for 3D. It does not have the large control surfaces required for performing "beyond the stall" maneuvers typical of 3D. The larger wingspan doesn't help any either.

However, if you are committed to using this plane, I would highly recommend a good four stroke, rather than any two stroke. Four strokes have better performance and a much higher level of torque in the mid range than a two stroke, and mid range torque is precisely what you want for 3D maneuvers (or any extreme aerobatics).

I would suggest something like a good used OS 70 Surpass. It's an extremely reliable, powerful engine, and should have no trouble pulling the 4* vertically. They can be had in the $130 to $160 range for a good used one.

You'll also want a large diameter, low pitch prop.
Dennis-

I've got a ST 51 on a 4*40. 10% nitro, 11x5 APC prop. It's fast and has unlimited vertical on a cooler day. I hate the way the muffler extension bolts to the cylinder. Other than that, it runs great.

I have an HB .61 in mine unlimitted vertical and a blast. I think it will do 90+ mph on a straight away. I have a 12-6 APC on it. Sig 10% baby.........Plane is 4yrs old and looks like hell, but flies great.

My son had a GP42 on his and wanted more power. So I got him a saito 72 for it. He loves it. 4 strokes make them fly different. Unlimited vertical. I had a KB 61 on my 4* 60 and changed it to a Saito 91. wow Flys much wilder with the 4 stroke. 61 had lots of power but not torq like a 4 stroke.

Randy

Heli,

Just my humble opinion, but I have had the OS46FX in a 4Star 40 and it was great. The plane had some mods that added weight and the wingspan was stock, so there was both weight and drag and the 46FX pulled it around with authority.

If you are looking for an engine that is versatile enough to allow you to grow into the popular 3D birds out there I think you will find that the 46FX will do nicely. I took that same engine out of the 4* and put it on a Profile Sledge 540 (that I built like a brick 4.8 lbs.) and it will hover 6" (not by me though[&:]) off the deck with plenty of pull-out. The new AX is getting good reviews from the 3D guys as well. I have one going into a Burrito this week, so I don't have first hand knowledge....yet. There are still plenty of 46FX's out there and the AX is priced nicely at $109 from Tower. I got mine from the LHS for $103, so I guess it is pretty even when you compare shipping costs to our obscene state sales tax.

Do what feels right to you, but just thought I would throw that in for you to consider.

Also, don't forget the thrust and or speed that can be gained from experimenting with props!

I am constructing a 4* 40 now. I selected the OS46. I have read several posts suggesting that shortening the wings by one bay on each side can improve the agility of the plane. I will fly mine with the stock wing size for a while before deciding on whether to shorten the wings or not.


Scott.