Ih82crash

According to Ralph this is the site for the power curve

www.toni-clark.com it says 6200 is ideal. Also a 20 8 at 7000 can't put out the thrust that a 23 8 at 6200 does.

RTK

My Feedback: (1)

The torque/hp curve I posted is from Zenoah. Zenoah.net that is where you can find all of their torque/hp curves
Ask Ralph (rcign1) if you think my numbers are wrong. Look at the curve and you will see that 7500 is where you want to be static for the most power (torque) out of the engine.
I can swing a mejz 22x10 at 7200 rpm hot with an open exhaust muffler.
If you are choking it with a restrictive muffler get rid of it, let it spin up
The only thing 6200 is good for is noise abatement in Europe

Ih82crash

I ran it without a muffler swinging a 23-8 prop and got 6300 RPM. My experience with that prop is that it gives the same RPM as the 22-10. That is an MSC prop by the way. Is it possible that the elevation is making the difference?

RTK

My Feedback: (1)

Not completely, the MSC prop is A LOT more load than a Mezj of the same size and it is more load than a menz too, or at least from the MSC props I have dealt with.
Like I said 7200 with a mezj 22x10, I bet I could not get 6500 with a MSC 22x10 and I would be down on thrust. Try a mezj22x10 and if you don't hit at least 6900 something is wrong.
What is your elevation, I can't remember??? But I will be passing thru in a month or so.

Nogyro

My Feedback: (10)

Ih82crash,

It sounds like your numbers are low on the G62. Here's what I got on mine at 580'.


Stock G62, 3 gallons of gas through it. B&B muffler, Stihl oil @50:1. Broke in with 2 gallons of 32:1. 50 Degrees.

22x10 Mejzlik 7350
23x8 Mejzlik 6750
22x10 Menz S 6650
22x10 Bolly Wood 6900
22x8 Bolly Wood 7050 cut down 23x8


RTK is right. The G62 likes to turn up. I'm now running an NX 22x10, and it is by far my favorite prop on my newly converted G62 Light by Ralph.
Wish I had some rpm numbers but I don't. It sounds like it's between the 22x10 and 23x8 Mejzlik, but the pull out from a hover is unreal. Best $25 I've ever spent.

Ih82crash

you guys are forgetting that altitude is a major factor with me. You are at 580' above sea level. I am at 5300 FT and the air density usually averages 7500' That means that I am essentially flying 7000 Feet above you. If I was at your altitude I am sure I would be unlimited also.

RTK

My Feedback: (1)

Don't quote me, but I remember Ralph (RCING1) saying that he only noticed about 100rpm difference between sea level and about 5000' on these G62's. When he gets back from the races maybe he will comment.
High density altitude stinks though.

Nogyro

My Feedback: (10)

Kind of off topic here, but since were talking about air density and rpm, do the YS supercharged 4 strokes see less performance drop at altitude as compared to gassers? I know all your diesel trucks that run turbo's can shove the air in the intake.

Tired Old Man

My Feedback: (1)

The MSC line of props are very wide throughout their length, causing a reduced rpm count from more standard prop shapes. That by itself will be one of the reasons for lower rpm numbers. The MSC props pull extremely well, but if you're using an engine that develops it best torque at a higher rpm then you should change props.

Density altitude also has a tremendous effect on engines and props. There just isn't as much oxygen available in the same amount of space for the engine to mix with the fuel, so a leaner mixture setting is needed. That same factor effects how well a prop performs. Remember a propeller is nothing more than a wing mounted in a vertical plane and develops lift horizontally by displacing air. The faster it turns, the more lift is generated, up to a point. The less dense atmosphere lessens the amount of "lift" it can provide. Turning higher rpms will help to offset (but not eliminate) the reductions caused by a higher density altitude.

In short, change props.

Ih82crash

Well I just traded a Brison 3.2 for a KNP 30 percent edge that I am going to put the zenoah G 62 on I will get a menz or an NX 23 8 and will report the difference Hopefully you are right. even if not the 62 is still an excellent engine with great performance.