Is there a hobby shop online that sells diesel engines that any of u guys know of??,,

Try Carlson in Phoenix

http://www.carlsonengineimports.com/

Ed Carlson is a pleasure to deal with.

http://www.carlsonengineimports.com/...eselinfo.shtml




Eric Clutton aka Dr Diesel also is highly recommended.

http://www.cafes.net/doctordiesel/default.htm

Or, how about trying the diesel conversion route? Here are 2 of my latest conversions:

RT
[email protected]

rmteo1,

What size prop will that LA 40 turn? I've got an MDS .40 Pro I'm thinking about converting. Do you do the conversions yourself?

rmteo1,

I'd love to hear about to OS.40LA conversion. I just picked one up as my first nitro engine to go along with my PAW.19.

I'm especially interested in your thoughts on:

- using a starter as opposed to hand flipping.
- noise comparision to glow
-idle behavior
-fuel

BTW those done look like Davis heads

ptgarcia,

You should get about 10,000rpm with a 12x6 and just under 8,000rpm with a 14x6 prop with 40LA. Yes, I make these things myself. Here is a pic of my shop:

bighead,

see my other post for more discussion on diesel conversions:
http://www.rcuniverse.com/showthread...84&forumid=145

Have not had problems with using an electric starter. Just be sure you turn over the prop by hand before applying the starter to make sure that the engine is not flooded (careful - turn over the prop slowly, do not flip it. A diesel, unlike a glo engine, is LIVE at at times, and may just start if you flip it.)

These are not Davis products. When (and if) I decide to make them available, they will probably be about $20 each (much less than what is currently available). Here is another pic of my shop showing the CNC lathe with bar feeder::

rmteo1,

If or when you decide to sell/market your conversions please let me know. I would love to try one. I'll also offer up my MDS .40 Pro for testing purposes if you need it.

How is idle and throttle transition on these?

rmteo

I understand about the diesel engine being on at all times, but I am confused about how you can start one without any power source being applied to the engine.

Can you explain how the diesel fuel fires within the cylinder?

Thanks

"When (and if) I decide to make them available"

I'd buy one in a heartbeat.
Please put me on your list!

[email protected]

Hi,

Diesels fire because the high compression ratio compresses the charge in the cylinder so much that it exceeds the flash point of the fuel (mainly Ether) and ignites it.

- A bit like a bicycle pump getting hot as you pump up the tyre (or tire in the States!)

David C.

Wow! . . . Some shop!

You work for NASA then?



I've got a drill in mine (Well, almost)

-DC

rmteo

Thanks for getting back to me on how a diesel fires.

I am looking forward to doing my conversion on my Mecoa/Leo 46.

Our engines that we call Diesel really are not so, but are actually compression ignition engines. The term Diesel refers to the original patents and design of Rudolf Diesel (1897-1898) for an internal combustion engine.

When air is compressed sharply, as in the compression up-stroke of the engine, heat is generated. We have seen this effect in a bicycle pump and in science lab when we were tads.

In a typical Diesel engine such as in Trucks, Tractors etc, this compression heat generated can be as much as 5-600 deg F or more which is sufficient to ignite the vaporized kerosene or Diesel fuel that is time injected into the cumbustion chamber to initiate the power cycle.

Our little engines do not have a fuel timing or injection pump so we mix fuel, Ether, Kerosene, lubricant & other ignition additives and operate the engine as a simple 2 stroke engine. The engine draws this fuel/air mix into the crankcase whereby it is compressed during the downstroke and passed to the combustion chamber through the bypass ports. All this is timed by the piston top or skirt or by a rotary or reed valve depending on the design of the engine.

On compression the heat generated is insufficient, in these little engines, to ignite vaporized kerosene. Therefore the Ether in the mix (Ether has a much lower flash point than Kerosene) must initiate combustion which it does nicely. Ether, in initiating combustion, fires the Kerosene and so it goes. This is why Ether is essential to the process and must be storage protected to minimize evaporation.

The variable compression feature is used to raise, or lower, compression sufficiently to generate enough heat and used thereafter to vary the ignition timing depending on the load (prop size) of the engine, similar to the timing effect of a gasolene ignition engine. Hope this is helpful...sorry for the lecture.

Idle and throttle responce?

Sandersga

Thanks for the feed back.. this makes since to me know and I am going to convert on of my Mecoa/Leo 46 engines to a diesel.

Jim

Many engines designed for glo-alchohol fuel can be converted to diesel with the replacement of the cylinder head with a variable head such as that made by Davis Diesel.

Keep in mind several things:

Compression ignition imposes greater stresses than glo-alchohol..especially on the Conn rod and crank due to the much higer compression ratio needed to operate.

The glo-alchol carburator is designed and jetted for alcohol..this means that the fuel/air ratio of an alcohol mix is about 5:1 or 5 parts air to 1 part alchohol. the fuel/air mix required for a kerosene (or gasoline) engine is about 15/1. All of this depends on temperature and atmospheric pressure, of course.

Your converted engine carb venturi opening will be too large, the needle valve will be too big and coarse and the spray bar jet opening is now too big.

This does not mean that the setup won't work, it just means that the alchohol carb setup is not ideal for a kerosene or gasoline mix. Note the 3:1 difference in the above mix ratios.

With this setup, you will find that rotating barrel on the carb won't need to be fully open for max RPM of the engine. This is OK as the fuel/air kerosene mix needs are now 1/3 that of an alchohol fuel/air mix.

In initial operation find the position of the carb barrel whereby the engine does not increase in RPM as you lean the engine out. Lock this position down as your new open throttle position. You will find that because of the ratios discussed above the engine will now use much less fuel vs alchohol for a given run time, theoretically 1/3 less fuel or 3 times longer time.

When you find the ideal carb and compression settings for the prop you use, the engine will idle lower than before and will transition from idle to full RPM nicely.

Diesels love back pressure, unlike glo. You can actually put a tube extender from the muffler outlet directed all the way through the fuselage exiting after the tail to exhaust all of the stuff. Or, at least an extension from the muffler outlet directed downward away from the plane.

Finally, yep Waldo, they surely do stink and they are sloppy and your Wife won't let you on the furniture and will make you change your clothes after flying. All of them do this and aromatic lamp oil instead of kerosene don't help none. Ya just gotta love the damn things.

Thanks. I gotta try one of these.