I have a 3W 75 in a H9 33% Extra. After 15 gallons of fuel through it, it just ain't getting the job done. It runs out of vertical pretty quick. I was recently told by a club expert, that I have the early version of this engine. He says there is a newer and better version that will produce considerably more power. Can anyone verify what he is telling me. he also says I need a ZDZ 80. I am thinking 3w 100, but he says that will overpower it. Dick Hanson did an articel with the exact plane and 3w 100 with canisters. Recomendations--?

Thanks in advance.

More power doesnt hurt. Thats what the left stick is for. I have a EMM Pegasus towplane that is rated for a DA-100. I have a 3W-120 on cannisters on it and it is also a great sport plane. Just no full power snap rolls.

Just found the ZDZ 80. Power is rated a full 1HP OVER the 3w 75. Looks like a better choice. Wish I had known that earlier.

I have a Lanier Edge that wieghs a ton (26+ lbs) My 3W-75i gives me nearly unlimited vertical . It's no rocket, but it's no slouch either. 3W 26x10 prop. Can't give you the rpm's right now, but if you'd like I'll get them for you tomorrow when I go fly.

Believing in manufacturer's HP ratings is like believing in the tooth fairy....
Better they should publish the max torque and and what rpm it is reached....
The G26 max HP is reached at 12,000...The prop that will let it turn 12,000 (it will) would be a dud on the airplane...Max torque is at 9000 rpm... The best prop is a Mejzlik 18-6, that DOES turn 9000 rpm....[8D]

Now put a Zenoah, converted or not, in a 33%...

My ZDZ 80 DOES turn a Mejzlik 26x10 at 6700-6800 and powers my 24.2 lbs Extra very necely.

The full 1 Hp more on the ZDZ versus the 3W may be stupid things but what is not stupid is that the ZDZ IS more powerful than the lower displacement 3W 75.

Max torque is a moving number - it changes with exhaust system setup used .
I have two different ZDZ80's and on same tuned full length pipe one turns 300 more rpm - the stock one 7000-the modified 7300
same Mejzlic prop so torque obviously moved up.
The mod engine also turns 26x12 ZM, 6450 on the ground and 7400 in level flight in a H9Edge . on big JMB can ,NOT tuned pipe.
I really don't know if any 100's can match it . Maybe they can -but have not seen one .
Note the 1.25 thick hub on the 26x12 -
Onboard tach verifies real in flight rpm.

Ok--I'm learning a lot here. But back to my original questions. Were there differences between early and later versions that would effect the power?

No difference that I am aware of, except they switched over to the Nikasil cylinder coating, but that was quite a while ago. They have a rear-induction and a side-induction version, maybe one is better than the other, I don't own one. I had a 3W 78 twin in my H-9 Extra, it was a sled because I had one of the original Extras they built, weighed a ton. Plenty of power, but not so good when it quit once!! Most guys are using DA/3W 100's in those things now.

What type of muffler did you have?

I have a same plane with same engine and fly very good.,i use a menzS26x8.

That engine should be enough for that plane.
WHat propeller are you using? WHat is your RPM?
WHat exhaust system are you using?

I have the 3w-75i, and I think it might be the best motor I have ever owned. I'm running the 3w 26x10 and the thing just flat out kicks ass. Don't know what RPM its turning, but I do know that the power is very consistant throughout all rpm ranges and has mega-torque, and I only have 4 gallons through it.

Well, with my crummy Globee tach, 3W 26X10 prop, 74 degrees less than 100 ft above sea level, 7100rpm. About 7gals through this engine.

Wow Dan, if you can get that many rpm's don't ever sell that engine it's a keeper.

I'm not trusting my tach. Time to get something that will give me someting more accurate. Except for some self induced growing pains with gas engines, this has been a wonderful engine for me.

OK--finally got to do a run up and tack---I live on the gulf coast, at least for now. Anyway with a Bambula 26-10 prop I get 6060 on the ground. The spec sheet states 1100 to 8100. Think I'll change the prop. Any other suggestions would be appreciated.

I don't know how much you aircraft weighs, but I am running a 62CC Taurus in a 1/3 scale Laser 200 (21 lbs) and it accelerates upward at 1/2 throttle. There is absolutely nothing wrong with a 3W 75. It is a very well made and powerful engine. 15 gallons (if you have not mistreated it) is barely running the thing in. Send it in for service or do it yourself. Maybe it just needs new reeds or a new plug (that little white thing in the top). Don't throw out a perfectly fine piece of German machinery because it needs a little servicing. A 1/3 scale model does not need a $1200 100cc engine.

Put a little less blade on it, try a Mejzlik 26X10 carbon prop , they tend to be a little less load than the wood wide-blades. You should be around 62-6500, make sure it's not too lean, see if there is a good tan on the plug, if not, fatten it up a 1/8th turn on the high side.

Tom

I would agree, 26x10 Mejzlik or Menz would be in order.