Cox Diesel Conversion Test Run

microflitedude wrote:Very nice.

I take it you're using the Killer Bee crankshaft?

Actually, after quading up my inventory of Killer Bee Cranks, I stumbled onto a Davis Diesel crank, still in it's pack, thus inspiring me to post the "Inventory Your Stuff" thread!

Stuck it in there and it was off to the races!

Electric starter
OK just watch it with those!
I did warn you about hydraulic locks didn't I?
But I am still happy you got it going.

Looks like it's running well.

George

nitroairplane wrote:Electric starter
OK just watch it with those!
I did warn you about hydraulic locks didn't I?
But I am still happy you got it going.

HA!!!! I WONDERED how long it'd be 'till that sentence got you! Yep, I know about hyd/lock, but it wasn't gonna go otherwise, and my arm was about to fall off from flipping that prop! So, I figured to give it a shot with the starter! In my defense/ I just "blipped" it over, and it started !

Ain't that why they made snap starters
Hey the diesel finger will come to you in time and you will learn to love it!

wow - thanks for sharing - goood job - and hoarding parts never hurts on rainy day!!!

"hoarding parts never hurts on rainy day!!!"

Ain't it the truth !!!

Nice weather...Fly !
Bad weather....Fiddle with the hardware !!!!

I had bought a cox Diesel Bomber. Haven't gotten a chance to run it as a diesel yet. I don't have any fuel. Runs great on nitro

Godsey3.0 wrote:I had bought a cox Diesel Bomber. Haven't gotten a chance to run it as a diesel yet. I don't have any fuel. Runs great on nitro

I got some ordered from Eric "Doctor Diesel' Clutton today...should say I mailed the check. With my area code the whole tab for 2 quart cans was $45.00 Interested to see how it runs in my P.A.W. .060 and the little .049 conversion!
Nitro will be thrilled as Diesel starts to proliferate on the forum !

Kim wrote:

Godsey3.0 wrote:I had bought a cox Diesel Bomber. Haven't gotten a chance to run it as a diesel yet. I don't have any fuel. Runs great on nitro

I got some ordered from Eric "Doctor Diesel' Clutton today...should say I mailed the check. With my area code the whole tab for 2 quart cans was $45.00 Interested to see how it runs in my P.A.W. .060 and the little .049 conversion!
Nitro will be thrilled in Diesel starts to proliferate on the forum !

Have you joined Nitro's Diesel forum?

Kim,

Excuse my ignorance, why diesel? What's the big advantage. I assume more torque at lower RPM's? no glow plugs? quieter maybe? I may be off base, just thinking of diesel car/truck engines

Just want to learn a little. Thanks.

cribbs74 wrote:Kim,

I assume more torque at lower RPM's? no glow plugs? quieter maybe?

All of the above. An .049 diesel can turn an insanely large prop ( 7 to 8") at 7000 to 9000 rpm. Plus, the run-time per ounce of diesel is much better than glow fuel. And lastly, you can mix your own fuel from locally purchased products, i.e. kerosene, castor oil and ether (the ether can be recovered from starting fluid -- John Deere starting fluid is usually considered the best with the highest percentage of ether). See this thread on brewing your own: http://www.rcgroups.com/forums/showthread.php?t=1295580

The downside: A lot of folks don't like the smell and mess associated with diesel fuel. Running an engine as a diesel is hard of parts -- sheared conrod pins and broken webs on cranks, broken rods and blown contra-piston gaskets. Normally, if you plan to run a diesel a lot, purchasing a heavier diesel crank will be less expensive in the long run.

I keep hearing "Web" in reference to cranks. What is the web, the drive shaft?

I believe the "web is where the arm attaches to the crank pin. or the crank pin itself.

RknRusty wrote:I keep hearing "Web" in reference to cranks. What is the web, the drive shaft?

Rusty -

When the crank fails, it will usually will happen in one of two places, although any point can fail. The splined area may crack away from the front bearing -- notice that it is relieved between the splines and front bearing, so the crank is thinnest in area. The second common point is the connecting rod pin. It will either shear flush with the web or the pin will break part of the web off (arrow). The diesel and KB cranks are more robust than the standard cranks. Also notice that the web has been ground away on either side of the conrod pin to lower the rotating mass of the KB crank. Standard cranks have a thinner web section and the web section is completely round.

Ah, okay thanks for enlightening me on that. I've built Mopar and Chevy hotrod engines, I guess that's what it's called on those cranks too. They look just the same.

cribbs74 wrote:Kim,

Excuse my ignorance, why diesel? What's the big advantage. I assume more torque at lower RPM's? no glow plugs? quieter maybe? I may be off base, just thinking of diesel car/truck engines

Just want to learn a little. Thanks.

Hey Ron,

Andrew listed some of the advantages and compromises with flying Diesel and all are legitimate...in my limited experience, but for me, the draw is that it's just another way to drag an airplane around the sky.

In the 90's, I built a Peck's "Prairie Bird", powered by a tiny Campus Co2 motor, and steered it around with a single channel "Albin" receiver and magnetic actuator, built and sent to me by a fine fellow named Fritz Mueller. It literally "puttered" around the sky (ANOTHER video I want to convert and post!), and I spent a lot of calm evenings, happily making laps high over the local ballpark. I was the target of much head shaking for that one too!!!!

It was also the first model I ever had that was partially "eaten" ! I lost it in a soybean field, and found it the next day in the condition shown...even the prop's leading edge had "tooth" marks !



Anyway, the diesel thing had bothered me since watching one fly at the S.M.A.L.L.-Fly back in 99' or so, and now, I've got some resources in this forum to help guide me. I don't know if they are really "Quieter" but their pitch IS a lot lower.

There is a big difference between the Killer Bee crank and Davis' Diesel crank...which is why I stuck it in the conversion. The Davis crank has no "lubrication" cut in the forward shaft, and just looks heavier all around. I should have weighed it, but didn't think to...may pull it all apart and weigh the different cranks to satisfy my nerd curiosity !

Anyway, that's my deal with the whole Diesel thing...

Andrew and Kim,

Thanks for the detailed replies. Who knows I may eventually go down this road.

When I get that new batch of fancy kerosene from Mr. Clutton, I'll do another run and post it as an "Edit" to my first post here. That way, maybe the stuff will stay together...this is my theory at least !

Forgot to mention, the partially eaten plane was probably feasted on by rats inhabiting the Soybean field. Either that or some really rugged caterpillars!

That was a neat looking plane. Never really thought about using a CO2 engine. I will have to try it eventually now. Are you going to re-build it?

Godsey3.0 wrote:That was a neat looking plane. Never really thought about using a CO2 engine. I will have to try it eventually now. Are you going to re-build it?

It was rebuilt, and worn out again !! I do intend to build a THIRD wing for it and try again. The radio is still working, but I'm having trouble with the motors. Nearly bought a NIP Campus a while back, but passed when the bids took off!

How does the turning setup work in it?