Diesel Motors

Hi

I have had a fair bit of experience with small diesels. Firstly you want to make sure your fuel is right. What fuel are you using? In my small diesels I run 33.33% castor oil, 33.33% Kero (or JetA1), 33.33% Di-ethyl Ether. In my racing diesels I use a high performance mix approx 20% oil, 30% ether and 50% kero and 1% to 2% IPN.

There is no sure fire way of starting a new diesel as you need to learn where the compression needs to be. Start off by flicking the engine so that it turns over a couple of times. Too much compression and it will be difficult to turn over. Remember, be careful, because once fuel is added it can start at anytime so watch those fingers.

Open the needle say 3 turns. Now prime or choke the engine with just a very small amount of fuel and give it a few more flicks. If it bites and does not want turn over, back off the compression a bit. If it still bites, you might have flooded it. On the other hand if it doesnt do anything after the prime and flicking it, you might need a little more comp. or perhaps another prime.

If it fires and doesnt keep running, give it a little more comp. Turn the comp. screw about 1/8 to 1/4 turn clockwise. If it fires and the prop rocks back and forth then there is too much compression. If it fires and runs on the prime then stops, open the needle a bit. If it fires on the prime and spurts heaps of fuel out the exhaust then turn the needle in a bit.

Eventually you should get it to run. Once you have it going good, you should not need to adjust the compression much for future runs. In other words leave the comp screw alone. When you have it running good, if it is spewing out black (burnt castor) then it is over compressed. If the castor is coming out clear or slightly brown then the comp. is correct.

Good luck!

Thanks warrenlead. I knew what directions to turn it I just didn't know when to turn it. Do I want more or less compression when breaking in?

You will notice with less compression the engine doesn't rev as hard. This is a good thing. As you increase the compression the speed increases to a point where it becomes over compressed and the speed drops off.

When breaking in you want plenty of oil and a rich fuel mixture. Start the engine and slowly bring the speed up and let it run for a bit then stop the engine when it starts getting hot. Let it cool then start it again and repeat the procedure. After a while you will notice the engine changes and holds a good steady setting. At this time it is ready to use.

The theory of diesel operation should be understood. Diesel fuel ignites by the heat created by engine compression. Of necessity diesel compression must be reduced when starting; it takes less effort to overcome the compression and the engine starts.

Once running the RPM's may be increased by increasing the compression. This is not an exact science because it takes some experimention with compression settings varying between engines.

The "flash point" of diesel is far higher than glow fuel or gasoline ergo the higher compression needed. Toss a burning match into an open container of gasoline or glow fuel and it will burn (but not explode): toss a burning match into an open container of diesel fuel and the match will go out.

Rudolph Diesel's idea changeed the IC world for all times.

bump

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Godsey3.0 wrote:Hello. I have asked several people about this but have never gotten a straight answer. I was wondering how to tell what direction to turn the compression on a diesel. Everyone just tells me to experiment with it but I don't want to ruin the engine. Do I want more compression or less. Thanks

Hey Godsey

Don't know if this will help (AND hope Mr. Clutton won't mind the copying of his instructions!), but thought I'd post it just on chance. I'm slowly working my way into Diesel Power, starting first with an .049 conversion, and now with a P.A.W. .06 from Mr. Clutton.

I have yet to get the time and mindset to test run the P.A.W., but will post my experiences in the Off Topic's. I intend to test-fly it on my faithful old Lazy Bee, once the engine and I get to be friends !



Good Luck...........Kim

SuperDave wrote:bump

No comments?

Actually save you are not entirely correct there because smaller engines especially those of 1 cc and below start at a higher compression setting and then are backed off once running own over 15 diesels under 1 cc all the diesels I have range from 0.05cc to 3.2nd and everywhere in between.
My standard diesel fuel for all "small" diesels is: 35% kerosene 35% di ethyl ether 28% castor oil and 2% iso propyl nitrate although I have had to have the ether as high as 50% for the first few runs of some of the smaller ones.

Kim wrote:

Godsey3.0 wrote:Hello. I have asked several people about this but have never gotten a straight answer. I was wondering how to tell what direction to turn the compression on a diesel. Everyone just tells me to experiment with it but I don't want to ruin the engine. Do I want more compression or less. Thanks

Hey Godsey

Don't know if this will help (AND hope Mr. Clutton won't mind the copying of his instructions!), but thought I'd post it just on chance. I'm slowly working my way into Diesel Power, starting first with an .049 conversion, and now with a P.A.W. .06 from Mr. Clutton.

I have yet to get the time and mindset to test run the P.A.W., but will post my experiences friends !



Good Luck...........Kim

Hey Kim Paw engines are great I own 2 and Because I live in the land of the Diesel I have got to run many of them and can honestly say I Garauntie you will love your .06 they are great little engines although the carb on some grottoes ones is a little crude they all run well.

Thanks Nitro, appreciate the thoughts!

I'm looking forward to breaking in this little jewel and bolting it to the Bee. I watched some guys having a big time with them at S.M.A.L.L. some 13 years ago, but had a lot going on then, and didn't want to branch out into power source.

Sometimes it seems like there are life gremlins keeping track of my activities, and every time I get something on the board, new pressing family and other issues jump up in front of my new project!

It'll happen though !

Kim wrote:Thanks Nitro, appreciate the thoughts!

I'm looking forward to breaking in this little jewel and bolting it to the Bee. I watched some guys having a big time with them at S.M.A.L.L. some 13 years ago, but had a lot going on then, and didn't want to branch out into power source.

Sometimes it seems like there are life gremlins keeping track of my activities, and every time I get something on the board, new pressing family and other issues jump up in front of my new project!

It'll happen though !

It happens all the time a fire in the shed,car stolen,crash,robbed,illness it all happens but my hobby makes me feel better when these things happen so i try and make time for my liesurely activities.

My reference was to the THEORY of diesel operation rather than the practice of small diesel operation where fuel is a every important consideration.

As an aside, during the early years of WWII, German Panzer divsions triumphed over Allied tank divisions primarilly with the use of diesel rather than gasoline as means of motive power. The 1942 Battle of Kasarine Pass is agood example)

Allied strategists, particularlly Gen. George S. Patton, realized the only way to defeat Gen. Erwin Rommel (aka: "The Desert Fox") was to cut off his supply of diesel fuel. That done German Panzers ran out of diesel fuel to their ultimate destruction.

(Facts you may NOT have wanted to know)

SuperDave wrote:My reference was to the THEORY of diesel operation rather than the practice of small diesel operation where fuel is a every important consideration.

As an aside, during the early years of WWII, German Panzer divsions triumphed over Allied tank divisions primarilly with the use of diesel rather than gasoline as means of motive power. The 1942 Battle of Kasarine Pass is agood example)

Allied strategists, particularlly Gen. George S. Patton, realized the only way to defeat Gen. Erwin Rommel (aka: "The Desert Fox") was to cut off his supply of diesel fuel. That done German Panzers ran out of diesel fuel to their ultimate destruction.

(Facts you may NOT have wanted to know)

I knew those facts actually but yes model diesels actually share very few thing with there larger counterparts.

What is the front little diesel engine in the "handful-o-diesels" pic in the gallery ? the one with the pointy spinner?

NeedNitro wrote:What is the front little diesel engine in the "handful-o-diesels" pic in the gallery ? the one with the pointy spinner?

That is a Ronald Valentine DiVa 0.098cc there was one on ebay a few days ago.
http://www.ebay.co.uk/itm/Rare-Valentines-DiVa-0-098-cc-Diesel-Model-Engine-NIB/310346361785?ssPageName=WDVW&rd=1&ih=021&category=34056&cmd=ViewItem#ht_2177wt_1189

i also have ordered a blitz 0.05cc engine that is almost half that size and weighs 5 grams.

Yeah, so anyway, I'll be paying a lot closer attention the next time there are some veteran diesel guys cranking up their engines. Maybe try to make it to S.M.A.L.L. this next summer.

Hey Nitro, perhaps you could post a video of your diesel engine starting procedures, including any problems that may rear their heads, and your fix for same?

Kim wrote:Yeah, so anyway, I'll be paying a lot closer attention the next time there are some veteran diesel guys cranking up their engines. Maybe try to make it to S.M.A.L.L. this next summer.

Hey Nitro, perhaps you could post a video of your diesel engine starting procedures, including any problems that may rear their heads, and your fix for same?

What size ar you talking?
I could do so with an old frog 100 (0.06 cuin) engine from the sixties that's a good size to use because is the same type of procedure for engines 0.5cc to 2cc once you go above or below that you change methods a bit.
I may be able to make a video in a week or two because I need to get some props and diesel fuel line for this engine.

On my 2.5cc Oliver Tiger replica racing engine, I have never changed the compression. The compression was set by the manufacturer and needs no adjusting.

On the small diesels I use for sport free flight, I need to increase compression to get them to start then back off slightly to achieve the desired smooth running speed. Sometimes if it's calm and I want it to go really high I crank the compression up to full speed and let it rip!

nitroairplane wrote:

Kim wrote:Yeah, so anyway, I'll be paying a lot closer attention the next time there are some veteran diesel guys cranking up their engines. Maybe try to make it to S.M.A.L.L. this next summer.

Hey Nitro, perhaps you could post a video of your diesel engine starting procedures, including any problems that may rear their heads, and your fix for same?

What size ar you talking?
I could do so with an old frog 100 (0.06 cuin) engine from the sixties that's a good size to use because is the same type of procedure for engines 0.5cc to 2cc once you go above or below that you change methods a bit.
I may be able to make a video in a week or two because I need to get some props and diesel fuel line for this engine.

Not sure Nitro...I'm kinda making this up as I go....but the .060 would probably be a good choice if it's what you consider a "middle of the road" type that most of us Diesel Newbies would want to teeth on...

Ok that is probay the ideal engine as it is very average and old.
Not the easiest to start but will run on pretty much everything.

Sometimes there is confusion between our model diesels and the automotive/industrial diesels.
First off, our model diesel engines are compression ignition engines and are not true diesels. They do not operate on the diesel cycle. (That requires fuel injection to control the burning process).
We brought this misnomer on ourselves back when there were two prevailing types of automotive/industrial I/C engines. Those with spark plugs and those with out. Those with out were diesels. So we called our compression ignition engines diesels. It’s stuck and that’s OK, but we should be aware of the technical differences. Don't confiuse the two, they are a totally different breed of cat.
Al

Big Al wrote:Sometimes there is confusion between our model diesels and the automotive/industrial diesels.
First off, our model diesel engines are compression ignition engines and are not true diesels. They do not operate on the diesel cycle. (That requires fuel injection to control the burning process).
We brought this misnomer on ourselves back when there were two prevailing types of automotive/industrial I/C engines. Those with spark plugs and those with out. Those with out were diesels. So we called our compression ignition engines diesels. It’s stuck and that’s OK, but we should be aware of the technical differences. Don't confiuse the two, they are a totally different breed of cat.
Al

yes and diesels and glow engines are extremely different i look at the size and weight difference between a tee dee .049 and a paw .8cc.
this is mostly because diesels have diesel knock which is a more powerful ignition so as to put into context the combustion of model diesel fuel is far more "powerful" than glow fuel so engines are built more rugged to deal with this hence the crank failures on some converted engines like the tee dee .010.

OK...that makes sense...man, there are all kinds of twists to this stuff!
One thing for sure, I've got a friend I'm helping to get re-started in U-Control, and he has the sometimes irritating habit of picking up my engines and flipping the prop through with his ear up at the exhaust...says he can gauge the health of the reed that way... All that aside, I'm gonna have to hide the P.A.W. from him!