I recently purchased a Goldberg 77" Edge 540 and i'm on the search for an engine. There is a guy here locally that is selling a Zenoah G38 at a good price. Would this be enough power for the plane??? I'm not necessarily looking for an engine with a ton of power. This is my first aerobatic plane and i'd like to get used to it before i drop something huge in there. Any info would be great!!!

I think the G38 would be okay. It's not the most powerful 38cc engine, but it'll get the job done. It's your first giant scale plane, so the 38 should be okay.

Thanks a lot!!! thats all i needed to know!

I am going to disagree, the G-38 is going to make a descent aerobatic airplane into a flying brick. My opinion is go with the ZDZ-40, Brillelli 36, or Brillelli 46. All of these engines will make this air frame fly much better.

If all you are worried about is saving a few dollars buy the G-38, if you want a good flying airplane, then go with one of the other engines.

The G38 engine is listed at 70oz.

The ZDZ 40 is listed at 45oz BARE engine. No plug, no ignition, no muffler, no battery.

The Brillelli 36 is listed at 50oz RTF.

Now in REALITY, you can add another 6oz for the muffler on the ZDZ. Add 3oz for a battery. Add 3oz for the ignition system. That takes it up to about 57oz.

The Brillelli is listed at 50oz RTF. I don't know if that really includes the muffler or not. Let's assume it includes the muffler and the ignition system with the battery. That would truly be the lightest combo.

You can easily take 8oz off the Zenoah with an aluminum muffler. You could still leave the magneto on it and you'd have a 62oz engine. Heavier than the others, but not enough to make it a "flying brick"

He got a chance at a good deal on the Zenoah and it's his first gasser. I'd say go for it. Even with an extra 12oz of weight over the Brillelli or 5oz more than the ZDZ it's not going to ruin the way the plane flies. It might increase the wing loading by 1 or 2 ounces at most. Probably not even that much.

http://www.towerhobbies.com/products.../gbga1045.html

1139 square inches at 12.5___ 13.5 pounds RTF

Let's say it DOES weigh 13lbs RTF with the Brillelli at 50oz. Calculate the wing area and you get a wing loading of 26.3oz per sq. ft.

Now add the ZDZ 40 at 57oz. I'll be generous and call it 54oz. Calculate the wing area at 13lbs 4oz and you'll get 26.8oz per sq.ft. wing loading

Now lets say you bolted the STOCK Zenoah on the firewall at 70oz. Thats exactly 16oz MORE than the ZDZ engine. Calculate the wing area at 1139sq in. and you'll get a wing loading of 28.8oz per sq ft.

ANY of those numbers is perfectly acceptable. YES, there are lighter options than the Zenoah. Thats a given. But he's told us that he can get the Zenoah at a good price and it's his first gasser. I stand by my original post. Go for it!!

Your numbers are skewed to favor the G-38. Brillelli does post the true RTF weight, so there 36 with ignition, muffler and standoffs is 50 ounces. Add 3.5 for a battery and you are at approx 54 ounces.

The G-38 as listed at Chiefs is 67 ounces for the bare engine. Add 4 ounces for their ugly lawnmower muffler or more realistically 6 ounces for a Pitts muffler and now you are up to 73 ounces.

Now let's take the same numbers you did 1139^2 of wing and ready to fly weight with a Brillelli 36 of 13 pounds. Wing loading = 26.3 oz per square foot.
Now add the more realistic weight of a G-38 (as listed at Chiefs, not made up by me) for a total of 14.187 pounds. Wing loading = 28.7 oz per square foot.
Now let's even get more realistic about the G-38, we haven't even added a cup mount or any type of mount for mounting it to the airplane and a spring starter so he can even start it. Which now puts your airplane at 14.5-14.75 pounds. Now at 14.5 pounds you are at 29.33 oz per square foot. 3 ounces per square foot heavier than the Brillelli.

Now let's even get more realistic, you have added 23 extra ounces to the nose of a 77" airplane over a lighter engine and assume you will balance without adding some lead. Good luck. Hope you enjoy flying a brick..

These numbers are for reference only, with either engine the airplane will not build at 13 pounds.

the one in my shop now is 15lbs 5 oz with a zdz 40 dual nicads aluminum spinner just doing a check over on it for a friend but flys well at that weight.

Your kidding right? Read what you just posted. No go RE-Read what I posted about engine weights and wing loading.


The Zenoah G38
http://www.horizonhobby.com/Products...ProdID=ZENE38A


The Brillelli 36. Advertised at 50oz RTF. So thats not REALLY what it weighs RTF? Okaythen that gets it even CLOSER to the G38 in weight. Not looking like much of a bargain anymore, is it?
http://www.scottellingson.com/brillelli_engines_009.htm


The ZDZ 40 advertised at 2.86lbs BARE.
http://www.rcshowcase.com/html/ZDZ/zdz40re.html

My numbers weren't skewed to favor anything. You claim Brillelli doesn't post a RTF weight. Check the link. It saiys right there in black and white "50oz RTF"

Check all the links. Do your math again.

We both agree the Brillelli could lead to 26.3oz wing loading if the plane weighs 13lbs.

I posted the G38 would have 28.8oz wing loading and you're telling me it'll be 28.7. Last time I checked, 28.7 was LESS than 28.8 that I came up with. How did I skew the numbers to favor the G38?

The G38 is a magneto engine and it comes from the factory with a mount and a muffler RTF at 71oz. My sincerest apologies, I was an ounce off at 70oz. It doesn't need a spring starter either.


Your post makes about as much sense as marrying a hooker that you met in Vegas. You wanna tell me again __ Where was I skewing the numbers to favor the Zenaoh?

The following is the reasons I called them skewed:
1. Above you say that you can take 8oz off the Zenoah with a aluminum muffler and have a 62 ounce engine.
2. Also you did not add the weight for some kind of mount, whether it be standoffs, cup mount or hardwood dowels, either way you add a couple ounces.
3. If the guy starting this post is going to use a spring starter it is even more weight.
4. Also as I stated above, the extra weight over a Brillelli 36 is probably going to require lead to balance, that is extra weight not accounted for.

Brillelli quotes their RTF weight as engine, ignition, standoff, muffler. Does not include battery.

Be perfectly honest I could not care less what engine the originator of this thread chooses, I am just giving my opinion and have no desire to get in a pissing contest. I hope FASTBALL48 has good luck with whatever engine he chooses.

My advice to Fastball48 is to buy that good deal G38, fit it with an aftermarket aluminium muffler which will give a much improved performance over the stock unit while losing a few ounces and go enjoy your model.

Down the road if the urge for increased performance bites you get the engine converted to electronic ignition which will significantly lessen it's weight.

Karol

Apparently, you can't read. I USED 70oz engine weight when calculating the Zenoah engine weight. I didn't subtract anything for the aluminum muffler. I SPECIFICALLY said, STOCK G38 at 70oz.


Again, he doesn't need a spring starter on a G38. You're just using that to justify calling the Zenoah a POS. Talk about grasping at straws................

It doesn't NEED a mount. It comes from the factory with an engine mount that is INCLUDED in the RTF weight advertised. Apparently, you can't click a link either.

He won't need lead to balance it. It's easy to move a battery back under the cockpit to balance a plane. No lead required. Funny you just mentioned lead in this post. No mention of lead before this one.

I hope he has fun with his new plane too. I'd snatch that Zenoah and go fly it.

I'm done with this thread.

If you look at post #5 paragraph #6, this is exactly what you said

"You can easily take 8oz off the Zenoah with an aluminum muffler. You could still leave the magneto on it and you'd have a 62oz engine. Heavier than the others, but not enough to make it a "flying brick"


Nowhere did I say Zenoah was a ***, my whole arguement was that it was too heavy.

If you look at post #7 I mentioned adding lead because of the heavier engine.

Now I am out of here....

Yup, and then I did the math using the 70oz engine weight because I KNEW somebody would hit me over the head if I used the lighter weight. I told you in post #5 that weight could be saved by switching to an aluminum muffler. And in post #6 when I actually calculated the wing loading, I used the 70oz weight. Golly ___ Somebody might even accuse me of "skewing" the numbers to favor the G38. Which is EXACTLY why I used the 70oz weight to do the calcs.

Then you come along and tell me I'm full of BS and I'm skewing the numbers. And I explained to you AGAIN how I had used honest numbers to calculate the loading for all 3 engine choices. And you STILL act like I'm cheating.

Then you start throwing out stuff like engine mounts and spring starters to make your case, because you knew you already lost the numbers argument. I showed you in plain arithmetic that there wasn't a pinch of dirt difference between any of the 3 engine choices and that he should buy the cheap one. So you start howling on about spring starter weights and engine mounting cups. NEITHER of which is required to run the G38. So, you're proving that you can't read and you don't know a thing about the engine you are slamming. The engine that you claim will make his plane fly like a brick just happens to be an engine you obviously know jack squat about.

Your simple assertion that the G38 was too heavy implies that it's a POS. We both know it. You said it would make the plane fly like a brick. If thats not calling it a POS, I don't know what is.

Here ya go. I'll cheat and "skew" the numbers for the G38. I'll use 62oz. Oh what the hell!! Lets call it 60oz. Woohoo, now we're cheating!!!

27.56oz/sq.ft wing loading.

Big friggin DEAL!!

The average Sunday flier can't tell the difference between 25oz or 30oz loading. He just wants a sport plane for his first gasser. It's perfectly acceptable to use the G38 in that situation. He's not looking for an IMAC or 3D plane. He JUST wants to get a cheap gas engine for his first plane. Will it do the job? Yes. Is it the lightest engine in the world? No, never said it was. But it's not that much heavier that it's going to make the plane fly like a "brick".

Wow, you sound very angry. BTW this is a discussion, not a arguement.

Don't ever think you know what other people are implying, you will usually be wrong..

Fatball48, your original post/question was perfectly informative...and the response you originally got was not only warranted, but adequate and acceptable to you. Hopefully you don't let the rest of this banter smear your judgement. Enjoy your project, and let us know how things go!

Chad

Could not agree with you more. Even a very experianced flyer would hardly notice the difference. In the days when we build kits I could never get the goal weight because I was to scared it would not be strong enough and used to much epoxy.

Go ahead and buy the G38 and have yourself some fun.If ya need it lighter down the road send it to:
Ralph,rcignitions.com
Good luck and let us know how it goes.