whee wrote:
During my discussion with Lycon about having them do the overhaul the tech stated that when they run the IO360s on the dyno after overhaul they produce 235hp and that is without their cylinder magic. I didn't have them do the overhaul and I'm only counting on 210hp but it will be interesting to see now much adjustment my prop, set up for O470K, will require.

They did my cont io-360 for my maule. Very happy with it. Cool to see this same engine going in a bear hawk.

Some major visual progress was accomplished today.

Looking Good!

Nice, dude!!

Dont stop now Whee! So close but yet so far.

Seriously, great job!

Kurt

Looks great Whee!

Thanks guys! It was a pretty serious ordeal to get the wings on and lift struts assembled so yesterday was very satisfying. We have some momentum built up and hope to reach some big milestones in the coming weeks. Now that things are more interesting visually I'll try to post more pictures/updates.

Nice one, man.
That is a really happy, rewarding moment in the build.
Take time to enjoy the moment!

Battson wrote:Nice one, man.
That is a really happy, rewarding moment in the build.
Take time to enjoy the moment!

Thanks Jono! Question; what grease are you using in your hinges? I don't know that it matters much but I used the extreme pressure lithium grease that I use in the main bearing of my Hamilton jet drive and now I'm wondering if I should have used something different.

Since you the one who first mentioned the grass was available on 17/35 at IDA, I have used it every time I drop in there (once or twice a year). Today to my surprise, I was told in no uncertain terms it was not available, bummer! I kept an eye out while there for your build, I was parked in front of the old Red Baron hangar, no grass but it still beat driving to IF from Inkom instead of driving. Looking great!

CG, I saw your plane yesterday but didn’t see you. We have a new airport manager but I doubt he had started any new policies. The previous airport manager was a decent guy but was very commercial oriented so I’d bet it was him that put a kabash on using the dirt.

I’m going to need bigger tires to gain some prop clearance...

Looking good! How long is that prop?

There are worse problems to have

robw56 wrote:Looking good! How long is that prop?

It's just a 88" seaplane prop off a C180 but it looks huge on the BH.

Sounds like that will be a rather noisy prop at the takeoff rpm of that engine. Might achieve more actual performance "thrust" with a shorter prop I would guess.

maules.com wrote:Sounds like that will be a rather noisy prop at the takeoff rpm of that engine. Might achieve more actual performance "thrust" with a shorter prop I would guess.

My noise footprint is high on the consideration list. We will be pull-testing this prop and a 82” prop to compare. Based on conversations with a guy in AK that has done field approvals for 82-86” versions of this prop on Maules I figure we’ll end up cutting this one down to 84”.

Even if left at 88” it won’t be as loud as a C185 with a long prop...but that’s not saying much[emoji57]

I believe the IO-360 Continental redlines at 2800 rpm.
You might wanna check the tip speed using Ponk's online calculator.

http://pponk.com/props/#1463774934977-1d7f57b4-6b2b

"If your tip speed is less than .88 mach you should increase RPM to achieve maximum thrust. If your tip speed is greater than .92 mach you should reduce RPM to achieve maximum thrust. Do not exceed the published operating limitations of your engine or propeller. Over .92 mach the airflow begins to detach from the propeller which decreases efficiency and dramatically increases noise. To improve performance and public relations you should consider reducing RPM so as to fall within the .88 to .92 mach range. Your propeller will be producing maximum thrust which is good for you, and less noise which is good for all of us."

An 88" prop at 2800 rpm = .96 mach on a standard temp (59*) day
84" at 2800, 59* = barely under .92.
But on a warmer than standard day, say 68 degrees, it's at .944 mach.

hotrod180 wrote:An 88" prop at 2800 rpm = .96 mach on a standard temp (59*) day
84" at 2800, 59* = barely under .92.
But on a warmer than standard day, say 68 degrees, it's at .944 mach.

Thanks. I'm familiar with Pponks calculator. My engine is the KB version which has a redline of 2600rpm though we have set it up to be capable of turning 2800. We'll do some testing to determine what rpm gives us the best performance.

You've got that last bit wrong. If the air temps increase the mach number will decrease.

hotrod180 wrote:I believe the IO-360 Continental redlines at 2800 rpm.
You might wanna check the tip speed using Ponk's online calculator.

http://pponk.com/props/#1463774934977-1d7f57b4-6b2b

"If your tip speed is less than .88 mach you should increase RPM to achieve maximum thrust. If your tip speed is greater than .92 mach you should reduce RPM to achieve maximum thrust. Do not exceed the published operating limitations of your engine or propeller. Over .92 mach the airflow begins to detach from the propeller which decreases efficiency and dramatically increases noise. To improve performance and public relations you should consider reducing RPM so as to fall within the .88 to .92 mach range. Your propeller will be producing maximum thrust which is good for you, and less noise which is good for all of us."

An 88" prop at 2800 rpm = .96 mach on a standard temp (59*) day
84" at 2800, 59* = barely under .92.
But on a warmer than standard day, say 68 degrees, it's at .944 mach.

This seems to be exactly right, empirically.

My prop is 83" and I reach .92 MACH just below freezing air temp. I have noticed on freezing cold days when I do full a static run-up to take off, the prop leaves a condensation spiral behind the prop tips which are reaching 0.92 MACH. This only happens when its cold out, and the temperature almost perfectly matches the calculator linked above.

I think 83 or 84" has been shown to work best on the BH in most climates. In very hot places, it would appear that a longer prop is desirable. I have seen some 86" props on some BHs.