Hi,
I am considering to buy a gas engine an was wondering what would my best choice. I was considering various brands: 3W Zenoah Fuji Brison and ZDZ. The engine size should be around 50-65c.c. I would like to have the best weight to power rateo as well as the most reliable. I saw that many acro competition planes with the 3W on the side but as we know most of the times it's a matter of sponsors. So I would have to rely on the personal experiese of each user. I don't pretend to spend a fortune, another point to consider

Here is a list of good engines:
3W, DA, BME, ZDZ.

norbe,
You left out a lot of information in your question. 50 to 65 cc is a big areana and there are lots of engines that fall into that category. On the other hand you stated that you wanted the best power to weight ratio and don't want to spend a lot of money to get it. You're not going to get the best power to weight ratio if you don't spend the money to get it. It's that simple!

Put the names of all the engine manufacturers you know of on a board and throw a dart at the board. Keep throwing until you hit an engine you are willing to pay for.

There are lot's of engines out there worth having but if you want the best in the size range you stated then you better be ready to spend at least $600.00

What do you think of the Brison 3.2 ????

It's a high quality, smooth running Sweetheart !

Check out the DA 50 at www.desertaircraft.com . I think you'll be impressed? Power? Beyond Belief. Reliability? if it comes from Desert Aircraft, you can count on it. Service? No equal. Engineering and Design? It is the latest thing out there and the design is outstanding. As the guys say that have them "This DA 50 ROCKS!" hehe

I am buying a Brison 3.2 but thanks for the advice...

One more thing, Just so I know, Is there any need of a fuel pump with the Brison ??? I now that glow engines do need one but do gas engines need it also??? Thanks

Norbe, No fuel pump is needed. The carb has a built in fuel pump and that takes care of the fuel delivery. You'll like your Brison for sure. Most if not all the Sachs based engines are excellent running machines. Many other Engines fall into this category as well... Regards. BobH.

Norbe,
For God's sake and for the sake of all your flying buddies, don't even think of getting the Brison muffler for your engine. They are little more than exhaust diverters and the noise will drive everyone crazy. I don't know who else makes mufflers for that engine but I assure you the noise will be a topic of discussion at your flying field unless you fly way out in the boonies. Brison mufflers are a piece of (^%

I would ask around more about how smooth that 3.2 Brison runs....there may be better in that department.

I have a couple frineds who aren't having very good luck with theirs. They both have converted to 3W and DA. It's your choice but when spending that kind of money you want to get what's best and has a proven reputation.