LongRifles Inc.

I have a 210 Moki in a 80SD.

8620 is the max RPM I'm getting out of a 17X12 Apc prop. According to buddies 8600+ is about all the Moki is good for. My speeds have been radared at between 100-120mph (depending on wind).

So, looks like I need more pitch. I've combed over APC's website and I'm not finding what I'm after. -would like to try something along the order of a 15x18, 16x17, etc to get the top end


Any help on finding a racing propeller vendor that carries a size like this would be appreciated.

Thanks.

C

airraptor

My Feedback: (66)

I have a Moki 2.10 also and have a 17x13 for it. you need to call APC directly. they are just 30-35 miles from me. I bet they have something that will work for you. i think they still have the 16x16 for sale

LongRifles Inc.

Ordered a 16X16.  Hopefully that'll wake the bugger up.

Thanks!

airraptor

My Feedback: (66)

When i get around to my Hanger 9 .60 size mustang with this engine i plane to run my Moki near 10,000. i ran some piston speed numbers and seem well with in reason. when get the 16x16 could work on trimming prop some. I think you should try to get atleast 9000 rpm but that is me. the prop shouldnt unload that much in the air.

mk1spitfire

I getting speeds slightly better than that on the 1.80 moki 16x12 apc. Have a 16x14 to try but due to 90m landing patch, she could come to hot with that extra pitch..

16x16 sounds evil. Hope that works for you.!!

Last weekend I used baby oil for the smoke fluid. Pretty good. Felt it left the smoke particles in the air longer. Not as white but catch it in the right area of the blue sky and it shows up well, depending on sun

I want to try a tuned pipe. That surly has got to pop the rpm up. Getting the header right, that would be custom made eludes me as its shortest length could be still to long to be on song on the pipe. Guess could cut pipe down too.?


[youtube]http://www.youtube.com/watch?v=15stDdjUuIQ&feature=related[/youtube]

LongRifles Inc.

I have a tuned pipe for my 210.  On my last SD (I'm  on #6!) I installed it inside the fuse.  it was a BICHE!!  Had to do some major, major surgery.  I pussed out this time and went with a simple pitts.

When #7 comes around I'll consider sticking the pipe back in.  I have another engine that I'm going to go through and spruce up a bit.  I think there might be some power to be gained here/there with the Moki.  Have to see.

10K on a 210 is about all it's worth.   I own a machine shop so I may trim that 16 pitch prop back to get more rpm.  I'd like to see just how much buzz I can wring out of this thing.

Nice vid by the way.

Chad

PS.  I stumbled onto a pretty cool fuel delivery setup/tune if anyone is having a tuning issue at all.  I'll post up if anyone is interested.

C

mk1spitfire

Was there any improvement in extra noise with that tuned pipe on the 2.10? Did you tune your header?

[youtube]http://www.youtube.com/watch?v=kZTLrzRzURs[/youtube]

LongRifles Inc.

actually the Pitts was much louder.  I could never really get the pipe set the way I wanted as I had such limited space inside the fuse with how I had my header set up.

I'm much better at TIG welding aluminum now so I plan on making a whole scratch built header on the next one.

mk1spitfire

Perhaps bench run it to tune it, if its harder to tune in model?

Was a quiet type tuned pipe? 1.80+ type size too?.

LongRifles Inc.

Will see on the next one.

Don't know if it'd work on a 180 or not.

mk1spitfire

On the pitts exhaust, I zip tied some white silicone extensions to each metal exhaust nozzle. This Helped ALOT, in keeping the oil off the bottom of the fuz and made cleaning easier.

Doc.316

How much run time do you have on your Moki? When we were racing dominators before the sundowners took over the Moki's would likae to be run a bunch. New they would turn a 17x12 around 86-8900. After 6 gal mine would turn the same prop around 9600. This was with the small "stacks" we were using on the dominators..(am not sure how much the muffler would knock off).

Steve

airraptor

My Feedback: (66)

thanks doc that sounds like alot of extra power in this size engine.

Doc.316

Yea it was a good engine Unfortunately my plane over the years (which started out right on weight) gained a little weight over the years and it was a couple of pounds heavy by the time it met it's maker up in illinois. The Moki is a ringed engine so it loved to be loosened up quite a bit and it got better with run time. It would fly a plane designed for a G62 no sweat.

steve

freakingfast

My Feedback: (3)

You got a strong engine there.
I was running a 16X16 on mine and it was the fastest prop for it. I don't remember what it turned on the Pitts muffler made for the Downer.

I benched a Mark 2.10 with a double quiet pipe and was disappointed a bit. Either the pipe was not working for it or I was trying to run it on a harmonic as it seems the header was so long.
I cut 1/2" from stock length and it lost power. Perhaps I should have kept cutting and I may have gotten better tune. I noticed the top speed was vary sensitive to the slightest throttle closure so I think there may be more power if the intake was opened up.

http://www.rcuniverse.com/forum/fb.asp?m=7671595

Nice guns by the way. .338 Lapua custom w/Nightforce here

mk1spitfire

Thats interesting you cut header and lost power but thought cutting futher would have gained power, i would have thought lengthening it would have gained more power? But when you cut , thats it!!!

Shame you didn't find the sweet spot.

Did it sound like it was on the pipe or close?