Got some questions for the experienced G62 users. I have a G62 I'm using in a Topflight P-47. It is equiped with the stock magneto and spring starter. It starts easy, idles fine and transition is excellent. I'm using a slimline pitts style muffler. With a master airscrew scimitar 22/10 I get 6400 RPM. The P-47 flies Ok with this set up. It's weight is 26 pounds dry. Tank is 24 0z. It is no rocketship however and it slows down fairly quickly when I put it in a steep climb. Any thoughts on this rpm performance and prop?

Well I have never owned one.. played with one or 2 at the field...

My main comment would be to change that prop and get something that will pull a bit better... ie: Xoar, Mejzlick, Menz, PT, NX, MSC, the list could go on. I like the Xoar for the price and performance, however the PT and Mejzlick are nice as well.

My other question would be do you need the weight in the motor for balance? If you dont I would consider sending it to RCIgnitions and getting it converted to EI and lightened up.. will help your overal weight which will also increase performance. He can prob knock off a pound or more. I dont know much about warbirds.. so this may not be a good suggestion CG wise.. others will have to chime in.

You may be able to find a little more performance with a different prop but at 26lbs you will still have to manage energy during manuvers.

I agree, prop is not the best, weight is another handicap. 22x10 is a good size for prop, but scimitars are for WWI bipes as far as I'm concerned. Aerobatic performance with the G62 begins to suffer over 18 pounds. A warbird doesn't need to do IMAC maneuvers, but it should at least be able to climb at something like scale speed. One of sinergy's recommendations should spin at least 7000 rpm, which would make a big difference for you.

Where is Ralph when you need him ???

I have same setup, about 3lbs lighter but fly at 5,000 to 7,000 feet elevation. I have found my g-62 really likes to run around 7,000 to 7200 on the ground and then unload in the air. I currently am flying with a Zinger 20x8/14 prop as recommended by some of the old time giant scale fliers. The plane flys really great with this combo, takeoffs are not as good but perfectly acceptable. You have to get up and then do a slight dive to let the engine "come up on the Pipe" but from then on she really screams. I fly with other guys using the TF P-51 and a G-62 with Mejelick carbon fiber props and I am getting at least as good performance as them and flying just as fast. I do have a bennet muffler on my plane as opposed to the slimline which I imagine is somewhat more restrictive. Converting to electronic ignition will gain you no power, just easier starting. My g-62 flip starts in three flips just like the EI engines so I don't see much to gain going that way. You need the weight up front anyway. As you might already know what works good on an aerobatic airplane doesn't always work on a warbird. If you don't like the idea of trying a Zinger 8/14 prop you might try a XOAR 22x8 or 10 prop as they seem to work very well for a good price.


Larry

I have basically the same set up on my TFGS Jug, but at 23#..
My G-62 has the Mag ignition and a Bennett muffler.
I had been running a Zinger prop, but changed to a XOAR 22-10, and it seemed like I had traded planes..
Good speed, climb, and plenty of reserve.. At 26#, your plane will fly OK, but that is a sizeable disadvantage.
The G-62 will improve dramatically with break in, the right prop, and a less restricted muffler...

Let me chime in on the prop as well.

I've flown G-62's (albeit, all modified by Ralph) on several planes, and there's no question for MY TASTES, that the Xoar props have outperformed everything else. At one point, I'd been through props from no less than 9 manufactures.

FWIW, I get 6800+ on a Xoar 23x8 with one of Ralph's engines. not sure what the performance difference would be between a modified and unmodified G-62, but that's a decent starting point, I think.

As mentioned before, you should be hitting around 7000 static give or take. I would probably start by changing the exhaust to a more free flowing one. Might want to change to a different prop too, mine likes the Mejz 22x10 on the plane it is in now, but that is not a war bird.

The slimline should be pretty decent as long as it is not fitted with the smoke coil. Mufflers like the b&b and Abell will outperform it a bit, but at the cost of significant noise gain. I run the slimline w/o smoke coil on one of my 62s, and have run it with the 23x8 and 22x10 xoar thus far and have no problems getting it into the 7000's. If you need the weight up front, AND CANNOT move other equipment further forward to assist in balancing, don't worry about converting it to EI. You'll end up at the same weight, and the power output of the 62 is the same either way. If you can move equipment to balance, converting it will save you weight, make the engine easier to start (no spring starter either), and thus give you better power to weight. Good looking plane!

Chad

Hi Guys, thanks so much for the great responses. I flew again today and borrowed a friend's 22/10 Mejzlik. Wow, differnt airplane. It did everything better. I was seeing 6700 rpm with the slimline and I think I can go a little more lean after I get a little more time on it. I should have known because I have a 28/10 Mejzlik on a 3W 100 and it really performs well.

I do need the weight of the stock G62 with spring starter. And I have everything as far forward as possible. Right now the Jug's performance
is very nice, and the high speed passes are good......but tell me more about Ralph???

Oh and the comment about the scimitar working well for WWI biplanes is
very accurate. I have a Polikarpov PO-2 (WWI technology used in WWII)
and it flies great. The radial turns the 20/10 about 6900 rpm. The scimitar
is also pretty close in appearance to the full scale original belive it or not.

Thanks again for all the good input. DWR.

I agree with the other guys , you should be around 6800 to 7000. I like a little more but we don't have restrictive mufflers. 22-10 Zingers always worked for me on my 36 pound Corsair. It would loop from level flight with proper throttle management as well as do other scale manuvers. No aerobatic champ but it did it's thing well. They slow down pretty fast at part throttle. I usually landed at at least 1/3rd throttle. Cut just a foot off the ground.

The 20 inch props didn't work very well on the warbird. They worked great onthe aerobatic planes that didn't need all the speed.

I'm looking at the high compression conversion and running on E-85. It is supposed to work very well.

bentwings, are you just changing the cylinder gasket/squish, or are you also getting in there and doing some porting as well? I know the power from the G62 can get pretty insane when on a cannister or tuned pipe, with some minor mods to adjust squish and porting. I've seen exhaust changes do more than other mods thus far, but I am curious about your project.

Try a 22x6-10 Zinger. Works really well on a G-62 Warbird combo. Pulls like a horse, and still has pretty good airspeed. Lot of guys don't seem to like Zingers, but they are well suited for warbirds.

My G-62's power went insane just on a good exhaust, no porting. If you let the engine breath it can make some real power. Yes my Yak is not a warbird but at 7800 rpm on a Vess 23A it can still make some good speed. Acceleration on mine of course is better since the aerobat only weighs 17 lbs full of fuel.

The point is to try to find an exhaust that will allow the 62cc's to giddyup and then a prop that can move air. My choice would be the Vess 22B on a G-62 on a good stock exhaust.

Edit Here is what a G-62 can do when breathing good air, no porting changes just a pipe.

http://www.youtube.com/watch?v=jbQcD9cYRDQ
http://www.youtube.com/watch?v=jps3cDMJnm4

Yeah i've seen em run with the Mac's products tuned pipe....MAN! I agree with you, seems the prop and exhaust are the huge difference makers. I was just curious if anyone has really gained anything significant with cyl gasket changes, a little porting...etc. They are already amazing performers with the right prop/exhaust.

I have the TF P-47 with the G62. I'm running a Zinger 22x10 with a stock muffler. The muffler has 3/8 pipes (about 2 inches long) welded to the holes in the muffler. I removed the straight sided carb stack. I'm geting just 6000 RPM. I have tried all the tuning tips but 6000 is the max. I have heard of folks pulling out the baffles in the stock muffler. Is this doable, worth doing? I'd like to keep th muffler because it fits the hole in the cowl. I plan to try a 20x6x14 as suggest above. But any other info would help.

thx
/colin

Well, try a test run on the ground with the muffler removed and open exhaust. You should see well over 7000rpm on that prop. If so, you will know where you are having problems. There is very little you can do to increase power if the exhaust is corked up. If you really want to try ripping the baffles out of your muffler, go for it.

Mark

What RPMs were you getting with the Zinger 22x10, and then with the XOAR 22x10.

cheers
/colin

What static RPM would you expect to get on this prop?
cheers
/colin

I PM'd you about payment details. Did you get my e-mail?

cheers
/colin

Hey Collin,

I did get your e-mail, sorry for the slow reply. Been swamped with work and riding the last few days. I will box up the muffler and let you know what the shipping is. Paypal is good for me, no problem.

Mark