I´m building my first big scale plane (GP 1/3 Pitts) and trying to fine a good 50 cc Gas engine.
Can someone tell me why is there such a difference in weight between engines?? The Fuji BT-50SB is about 74 oz(heavy end) and the DA-50 is 47 oz(light end). Same happen with other brands. There is a difference of 57% when compared to the DA 50 weight......
Please comment.....Thanks
Marcos

Spend the extra money and get the DA-50, I have mine and am going to mount it on a 27% Extra 300 85" wingspan, The DA-50 weighs 3.13 pounds with muffler and puts out 5 horse with a 22x10 prop, the FUJI 50stb wieghs in at 5.29 pounds with muffler and swings a 20x10 prop, FUJI advertises 5.2 horsepower that is sort of high I would like to see it on a dyno, but DA really puts out 5 but the Fuji is still questionable... If someone else could comment on the Fuji that has some experience with it...

Horsepower claims are only worth the paper their printed on. A better "stake in the ground" is to see how fast each engine turns a specific size and brand of propeller. The more powerful engine will turn it faster.

Weight? The Fuji, being a magneto engine, will be heavier due to flywheel, etc. The DA, ZDZ, 3-W, all those "application specific" R/C engines will be lower weight.

But, watch out for some manufacturers claims about engine weight. Make sure the total weight includes the prop nut, spark plug, ignition system, battery, muffler, mount, etc.

You can find some engines that claim to weigh 2.5 pounds. "Oh, do you actually want this engine to run? Then it'll weigh a bit more."

Dick, thanks for your time and comments. Can you tell me if there any extra equipment needed to run the DA 50 engine(extra battery power pack, ignition system, etc)??? This is my first gas project and I´m confuse with some articles I´ve read recently. I understand that some engines need extra equipment and some other don´t.
Thanks
Marcos

Hey Nieto I will jump in again, go to www.desertaircraft.com the DA-50 comes with , the motor,electronic ignition box, nuts bolts, and mine came with standoffs, the only other items you will need is a NiMH battery pack(thats what I got), a spinner, and a ignition on/off switch. hope this helps... P.S. www.chiefaircraft.com sells them too.

Comparing the Fuji 50 to a DA 50 is like comparing a Chevy to a BMW. They will both get you there, but how is the difference. From everything I have heard, forget the Fuji and go with the DA. I got mine yesterday - what a beautiful piece of machinery! However, don't forget that there are other great 50's around, made by BME, Fox, FPE (Sig), Brison etc. They fall in between the two you mention weightwise. All are very good.

another thing some guys don't think about is where the weight is located. With a magneto type the weight is forward on the engine. With electronic ignitions the weight of the battery and module can be moved forward or back. This can have a pretty good effect on the CG and how much if any lead has to be added to either end.

Yeh Dan you have more versatility, you can put ignition module and battery together in front or back of firewall or serperate them or what ever, but that can save alot of hard headaches when it comes to getting the CG right...

What is lead? OK, just kidiing, but in 10 years now I have not added one ounce of lead to any model. If you chose the right engine and move your battery packs (plural) around you can always get the right balance. Choose wisely, the sage says!

I would recommend the brison 3.2
Good price, great engine.

The DA is by far the cream of the crop! The BME and 3W(w/new ignition!) are great also. I personally do not care for the older Brison's(timing collar). The Zenoah's, Fuji's and such have their place in scale warbirds but the electronic ignition models are preferred in acrobatics.
I absolutely love my DA-50(GP Christen Eagle) but I am also quite fond of my 3W-75(AW 31% Edge). I have flown BME's(excellent) and Brison's(good). While the rear carb models have better air flow, they are quite a pain sometimes for setup. The side carb models may have air flow problems but are much easier to set up throttle and choke. Your choice is tough but with the Pitts, lite is good....

The reason I like being able to move the weight of the ignition and battery back is to get more of the planes weight toward the CG rather than on the ends of the fuse. My current project is a perfect example, it's a D&L Designs 80" edge. With a Brison 3.2 in the nose and with the battery, ignition behind the firewall it balanced with the elevator servos in the tail and the rudder servo and flight batteries way forward. With the ignition and battery in front of the firewall on the engine box I had to shift the flight batteries and rudder servo several inches back. I like the flight characteristics of my planes better if I can get the weight more toward the center.

I have my GP Pitts with the DA50. Unlimited vertical. CG aft at limit without adding lead. Nice Flying plane.

Nieto_Marcos - The first thing I would ask you is how would you characterize your flying style? Are you a more scale type pilot or do you fly 3-D?

I am currently flying a G.P. Pitts with a DA-50. I also had a Fuji-50 in my first gas project with this airplane. The Fuji ran very well for my style of flying, which is scale aerobatics. The only issue I had with the Fuji was that it was hard to flip start. I had one of the earlier models, but I understand the newer version has been improved to make it easier to start. If you are leaning this way I would really check this out before purchasing. Mine was a real bugger to get it going. Once it started it ran very well and provided ample power for my flying style. Never had a dead stick.

On the my second gas project I decided to go with the DA-50 mainly because I wanted electronic ignition and I felt the DA was best in class. The DA is the cream of the crop and the power difference is very noticeable. The Pitts is not your typical 3-D machine, but if your inclined to fly 3-D then I would definitely go with the DA-50.

The Fuji actually ran a bit smoother than the DA simply because of the large flywheel on the crankshaft. The Fuji was much easier to mount with no stand-off spacers to contend with and there was no cutting into the firewall like I had to do with the DA because of the carb location and cowling space to work with. I used custom made spacers from Aerografix with a Pitts style muffler. You only need one battery with the Fuji vs. two with the DA. Engine for engine the DA is by far more powerful, but then you have to determine what you need and eventually want in making the final decision. Both airplanes balanced out without requiring any lead. I have attached two pictures of each engine showing how the DA and the Fuji mounted.

Hope this helps