Mod IV with 582, setting prop pitch question

Hi guys!
I got my first engine run in last weekend. However I could never get it to 6000rpm. I have a new Warpdrive that I set to same pitch as the wood GSC (?) that I took off. At least I set it to the same spec as what the builder put in the log book. I followed the instructions for the Warpdrive to the letter, but maybe the different prop will need a different pitch. Has anyone else had to fine tune the prop for max rpm? Should I just start decreasing the pitch 2 degrees at a time until I get the rpm right? From what I've read, 6000rpm static ground run is what I'm looking for.
Thanks,
Jay

A different brand prop may require a different pitch setting. Even a same brand prop of different diameter will. So I would set it up for a recommended static RPM for that prop and then insure you are getting 6800 rpm on takeoff roll. What was your static RPM with the GSC propeller? I have read anywhere from 6100-6300 rpm for static, but I am an new Kitfox owner so will defer actual numbers to either more experienced owners, or to the prop manufacturer. I'm sure if you called Warp Drive and told them your which of their props you have and that it is on a Kitfox they can tell you what static RPM you should set.

Forgot to mention that I will be out and hopefully will be flying my Kitfox this weekend. It is also a Kitfox IV powered by a 582 and Warp Drive prop. When I am out there I'll let you know what the static and takeoff RPM are.

6800 is pretty high. What will happen to the rpm and egts when you level off and the prop unloads?? JImChuk

I'd assumed that like any other airplane you would pull the throttle back. Even some production airplanes can exceed redline RPM in level flight at full throttle. I have a lot of time in C-172s and C-150s and they will exceed redline rpm if conditions are right if you don't pull the throttle back.


The 6800 is directly from the Rotax Operating Manual for the 582

"Verify that engine reaches full power rpm during take off roll"

and

"Take-off speed 6800 rpm (max. 5 min.)"

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Originally Posted by 109JB

Forgot to mention that I will be out and hopefully will be flying my Kitfox this weekend. It is also a Kitfox IV powered by a 582 and Warp Drive prop. When I am out there I'll let you know what the static and takeoff RPM are.

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You're not flying into Indiana are you? I'm always up for a visitor. 36II
jay

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Originally Posted by avidflyer

6800 is pretty high. What will happen to the rpm and egts when you level off and the prop unloads?? JImChuk

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The engine break in schedule from LEAF doesn't show a max RPM. The bar graph just shows it going off the chart. For some reason 6000rpm comes to mind as a good static full throttle. But I only get 5500 and it will slow down to 5000. Although the egt's go down as it hits full throttle. I never did get the full break in done as it was getting so hot and would not cool down unless it was shut down. It did run much better everytime I started another run.

The log book that came with my bird is pretty bad, but he did write down a lot of notes on what prop pitches he tried. I have no idea what his starting setting was, but he had a couple flights in and increased pitch from 15.5 to 16 degrees. Static rpm went from 6200 to 6000. At 60mph climbout he had 6200rpm. Egt's were 1300 but were reduced to be in "spec". Then the next flight he went back to 15.5 degrees but now only gets 5800 to 5900rpm static. Humidity? And ten flight hours later he reduced again to 15 degrees for better climb. Twenty hours later he went back to 15.5, then to 16 again. He messed about with carb jet needles to try and reduce egt's as well. No good notes after that. Funny thing, the wood prop has a 100hr or 5yr TBO. He kept checking prop torque well past the 100 hours. That's why I went to the Warpdrive.

I would forget about what the guys numbers were with the GSC prop. As was already mentioned, one prop will be way different from another. For that mater, would you expect a 70" square tip warp to run the same pitch as a 70" taper tip warp prop? Of course not, and they are made by the same company but their shapes are different. Your main concern it your static rpm when you go to set it up. Most guys use about 6250 or even a bit less for static prop rpm. Once you are climbing out, you will likely see higher rpms as the prop unloads a bit from it's static setting. High EGTs are a killer on these 2 stroke engines. And in very short order as well. Not at all like a 4 stroke where maybe the valves start to burn after a while or something. But like maybe in one takeoff when you pull back to cruise rpm she quits. More prop load and or richer mixture = lower EGT temps. Two 582 manuals that I have say: Match propeller to achieve above indicated full load rpm. Indicated rpm was 6500 for 1 minute for the 582 with dual carbs and oil injection. Another thing to consider is the accuracy of the tachometer. Many of the analog tachometers are very inaccurate. A tiny tac is usually very accurate. Do some searches in the archives on any of this, and you will see I'm not the only one saying this. JImChuk

Just stating my setup.

Rotax 582 Grey Head - GSC prop brand new.
11 degree pitch nets me close to 6400rpm static.
On climb out I get right at 6800rpm at full throttle and I climb out at 1000fpm in summer time in a model II.
I cruise at 5100-5200rpm and get 65mph IAS and EGT's sit around 1050F.

You have a different prop so things will be different obviously but just giving my setup for those it might help.

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Originally Posted by beeryboats

You're not flying into Indiana are you? I'm always up for a visitor. 36II
jay

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Not going anywhere really this time but I'll keep it in mind. This weekend will hopefully get me checked out in the Kitfox. I have about 300 hours tailwheel time but due to health, life, and other issues I haven't flown in about 5 years. I know I'll be rusty, and maybe this weekend we will find out just how rusty. Hopefully not too much.

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Funny thing, the wood prop has a 100hr or 5yr TBO

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If I am right, the GSC Prop overhaul time is 5 yr / 500​ hours.

You are right, but still mine was way past the 5 year mark. Needed a new prop anyway. Almost went with the single bolt pitch adjustable one, don't remember the brand.

So I got about an hour of flying in and near as I could tell with the jumpy tachometer i was at 6800-ish during shallow a climb after liftoff. Once in level flight I'd guarantee that if I firewalled it in level flight it would have exceeded 6800, but I didn't let it do that. As far as static RPM, the brakes wouldn't hold for a full throttle run up. It would start rolling about 5500 rpm. During the flight I was too busy keeping controlling the airplane and forgot to look at the tach during the first part of the takeoff. Shortly after starting the roll it looked like it was around 6200, but like I said the tach reading was fluctuating badly. I definitely need to get a new tach.

Pulling my hair out looking for prop protractor today. Never found it, so it's a good excuse to go buy a digital level and really dial the prop in.

Now I'm really stumped. My fancy digital angle finder is showing 11 degrees pitch. I would think it should wind up like a turbine with that little pitch. Think it could be a mixture issue?

I wonder if you are reading the level correct..... Also, are you sure your tach is correct? A lot of the round ones are way off. Get a tiny tach and then you can believe the readings.

I got a TinyTach on order.

So I went flying today and here is what I got. This is with a new tach, a tiny tach installed as well and both of these checked using an optical tach and all matched very well.

Static was 6000 rpm, which was the same as during the takeoff roll.

Climb at 65 mph (Kitfox IV) was about 6200 rpm

full throttle in level flight was about 6600 rpm

My prop is a Warp drive but I haven't measured the diameter or the blade pitch yet. It is whatever the old owner had it set for. It is on my list to check this and record it, as it should have been in the logs, but I haven't got to it yet.