Author Topic: What is your starting drill for a Diesel both hot and cold starts? (Read 3902 times)

frank mccune · « **on:** September 08, 2015, 08:03:10 AM »

Hello all:

Once again I have been bitten by the Diesel Bug and have removed my Diesel powered airplanes from storage.

I would like to know of a good starting drill for these engines. The engines are: ST G20/.15D, MVVS D7. and an O.S. .40 with a Davis head. I have the engines adjusted to peak running settings so that I will have a benchmark as to establish a standard for adjusting the engine for starting cold. Hot starting is a mystery to me.

The fuel is fresh and the engines start very quickly with a bump of an electric starter. Without the electric starter, cold starting can be a problem. However, there is a bright spot in this drama. The one ST will start on the fourth flick at times with two drops in the venturi, and the fuel choked to needle valve. This, I can not repeat at all times. All of these engines have great compression with no leaks.I would like to just hand flip the engine to start it. I have been told that I am living in the past by not using an electric starter. I see them as a crutch for poor engine operating skills.

What I would like to do is to demonstrate to all of the naysayers in in our club that Diesel engines can be fun to play with for spot flying. Anybody can start a glow engine but it takes a man to start a Diesel! Lol

Oh yes, on YouTube, the chaps who demonstrate running Diesel engines just walk up to the engine, flip it a few times and it starts. How do they do this? Are the starting a hot engine for the camera? YouTube demonstrations of FAI Team Race are awesome! That would be my dream come true as to starting a Diesel! Lol

Suggestions please!

Be well my friends,

Frank McCune

Motorman · « **Reply #1 on:** September 08, 2015, 08:54:58 AM »

if it's cold just over prime it with the needle valve opened up. If you get it too flooded you'll have to back off the compression so it doesn't lock. If it's hot and hitting you hard, prime the exhaust. Seem counter intuitive but it works.

MM

frank mccune · « **Reply #2 on:** September 08, 2015, 03:34:30 PM »

Hello Walter:

Thanks for the reply!

How do I over prime the cold engine? Do I inject a few drops of fuel into the venturi, exhaust port or both? I do not get any sign of the engine wanting to start either hot or cold.
Is this an indication that the engine is flooded? Too little fuel or too much fuel?

Right now I am using the following drill to start a cold engine:

Choke to get the fuel to the nva.

Prime the venturi with about three drops of fuel and start flipping. Sometimes this works on one ST but not the other.

Do the above but prime a small amount of fuel in the exhaust port. Sometimes this works if I back off the compression about 1/4 turn.

Some times, I have to open the needle valve 1/4-1/2 turn and increase the compression a bit to get it running.

As you see, there seems no standard drill so far as to starting these engines. I am looking for a starting drill that will work on each engine. Of course, there is always the electric starter but I feel that using one is cheating but if it makes life easier, the heck with tradition. LOL

Be well my friend,

Frank McCune

bob whitney · « **Reply #3 on:** September 08, 2015, 03:56:10 PM »

what fuel are u using and what prop are u using on each engine???

Les Akre · « **Reply #4 on:** September 08, 2015, 05:19:52 PM »

I'm by no means an expert...but this has worked for me for a cold start: If running on the bench, choke to bring fuel to the needle. For most engines, richen up the needle about 1/2 to 3/4 turn from your optimum setting when starting cold. Then with the exhaust port closed, a few drops into the venturi, and a small squirt on the side of the piston, then start flippin'. As you flip and the piston opens on the exhaust port, it will suck in some of the ether vapor, which is what you want. The ether is what gets them going when it's cold.

If the engine is a high compression racing type, bolting on a larger diameter prop than what you fly with just to get the engine running and get some heat into it can be helpful.

When they are hot, each engine seems rather individual. Some you can just refuel and flip, others need an exhaust and/or venturi prime.

To further complicate matters, often the engine behaves completely different when in a model.

Just try a few things and eventually you'll develop a procedure.

Les

frank mccune · « **Reply #5 on:** September 08, 2015, 07:56:06 PM »

Hello Bob, Les et. al.:

Bob, I am using an 8x6 nylon, and a Cox gray 8x4 on the .15 engines and an 11x5 wood on the .40. The fuel is "old" DDD. I also have some freshly brewed Home Brew that I may try to see if the fuel is at fault. I have two unopened gallons of DDD fuel that I may use if the Home Brew does not improve conditions.

Les, in the 70's I used to purchase my model airplane supplies at a hobby shop on Whyte Ave. Is it still in business?

Thanks for the replies,

Frank McCune

bob whitney · « **Reply #6 on:** September 08, 2015, 09:31:56 PM »

les said it better than i could with the 15's find a heavy 8 inch prop when they are cold .the 11/5 should be ok on the 40 .i have not had much luck with the davis head . the chamber is too big

what is DDD fuel

qaz049 · « **Reply #7 on:** September 09, 2015, 07:05:42 AM »

Quote from: frank mccune on September 08, 2015, 08:03:10 AM

Hello all:

   Once again I have been bitten by the Diesel Bug and have removed my Diesel powered airplanes from storage.

   I would like to know of a good starting drill for these engines. The engines are: ST G20/.15D, MVVS D7. and an O.S. .40 with a Davis head. I have the engines adjusted to peak running settings so that I will have a benchmark as to establish a standard for adjusting the engine for starting cold. Hot starting is a mystery to me.

   The fuel is fresh and the engines start very quickly with a bump of an electric starter. Without the electric starter, cold starting can be a problem. However, there is a bright spot in this drama. The one ST will start on the fourth flick at times with two drops in the venturi, and the fuel choked to needle valve. This, I can not repeat at all times. All of these engines have great compression with no leaks.I would like to just hand flip the engine to start it. I have been told that I am living in the past by not using an electric starter. I see them as a crutch for poor engine operating skills.

   What I would like to do is to demonstrate to all of the naysayers in in our club that Diesel engines can be fun to play with for spot flying. Anybody can start a glow engine but it takes a man to start a Diesel! Lol

   Oh yes, on YouTube, the chaps who demonstrate running Diesel engines just walk up to the engine, flip it a few times and it starts. How do they do this? Are the starting a hot engine for the camera? YouTube demonstrations of FAI Team Race are awesome! That would be my dream come true as to starting a Diesel! Lol

   Suggestions please!

   Be well my friends,

   Frank McCune

Most of the posts so far suggest starting techniques that will flood the engine as a first step. This initiates a sequence of other steps to unflood it which prevent first flick starts.

If the cold engine has any after run (which it should) flush it out with kero.

Assuming the engine is set with the compression and needle settings from it's last good run, then it should run ok on these unless something major has changed. ie weather, fuel mix etc.

Then fill up the fuel tank with either the tubing crushed off or temporarily remove it from the NVA. Reconnect tubing or uncrush it.

Close the piston and give a decent prime against the closed piston.

Turn the engine over twice. Don't choke it. The prime should give an engine burst sufficient to suck the fuel up the tubing.

Give it a good wack.

It should start.

It will probably burp until it reaches running temperature. Hold the engine nose down (if possible) until it smoothes out.

Make slight running adjustments if necessary.

Follow the same procedure for hot starts.

bob whitney · « **Reply #8 on:** September 09, 2015, 08:01:27 AM »

it is almost impossible to get one flip starts cold .with the TR diesels we try not to adj the comp so the needle is opened up about a turn and then after it has wormed up it is turned back in

everything has to be perfect for a one flip start ,figure out what it takes to get a four or 5 flip start on a reg bases

still dont know what DDD fuel is

frank mccune · « **Reply #9 on:** September 09, 2015, 08:44:42 AM »

Hello Bob:

DDD is Davis Diesel Development, a supplier of the Diesel conversion heads. He also sells Diesel fuel ready made for Diesel engine use. When I used his conversion heads,.15, .36, and .40 I was unable to hand start an engine and had to resort to the electric starter. This told me something about the conversion heads.

Today I am going to attempt to use my HOME BREW fuel to determine if makes starting easier but with the temperature predicted to hit 95 degrees, I may elect to say indoors! Lol

Thanks for the replies,

Frank McCune

bob whitney · « **Reply #10 on:** September 09, 2015, 11:28:09 AM »

what are the %'s in your fuel

Les Akre · « **Reply #11 on:** September 09, 2015, 07:32:14 PM »

Hi Frank

The shop you were referring to was likely "Moro Craft Hobbies" and it was a good one. Definitely the place to go if you needed Enya parts...

When the owner died, the Son took over for awhile, but he really wasn't "into" it and the business failed soon after. It's really too bad...we don't have any hobby shops like that around here anymore.

BTW, although I thought it obvious, when squirting fuel into the exhaust port, keep the piston closed so as not to flood the engine. A flooded diesel is many times worse than a flooded glow for whackin' the fingas'

Les

Quote from: frank mccune on September 08, 2015, 07:56:06 PM

Hello Bob, Les et. al.:

Bob, I am using an 8x6 nylon, and a Cox gray 8x4 on the .15 engines and an 11x5 wood on the .40. The fuel is "old" DDD. I also have some freshly brewed Home Brew that I may try to see if the fuel is at fault. I have two unopened gallons of DDD fuel that I may use if the Home Brew does not improve conditions.

Les, in the 70's I used to purchase my model airplane supplies at a hobby shop on Whyte Ave. Is it still in business?

Thanks for the replies,

Frank McCune

frank mccune · « **Reply #12 on:** September 10, 2015, 07:42:47 AM »

Hello All:

First to answer Bob's question as to what mix I am using. My mix is 30% ether, 25%castor oil, 2% Amsoil DII and the remainder kerosene. Perhaps I am a bit low on the ether so I will bump it up to 40% for the next batch. I chose the 30% ether because I though with the temperatures in the 90's, I could get away with less ether. The HOME BREW works as well as the DDD fuel. The engine is a MVVS D7 2.5.

I did notice several things yesterday that were happening. The fuel would drain back into the tank after I had choked the engine. I had to raise the tank a bit higher than the nva to prevent this. The tank is now higher than the nva.

When setting the compression for a cold start, I had to increase the compression to where the engine would just barely turn over. The compression had to be decreased with about every flick to enable the prop to be turned. The engine would then start in a very over compressed state but would run long enough for me to adjust the compression. I did not have one incidence of getting whaked by the prop. Perhaps I am being too frugal with the prime.

Priming on the side of the piston did nothing but a couple of drops in the venturi seemed to work. Choking did not appear to do anything beneficial. Perhaps a few drop of fuel into the open cylinder al la glow engine may help.

I tried a 10x4 wooden prop but had visions of the crank pin saying goodbye to me. I think that 9x4 wooden prop is a large as I want to go on a .15 engine.

I will try again today as it is to be 74 degrees with rain.

Thanks for all of the help! Any other suggestions?

Be well my friends,

Frank McCune

bob whitney · « **Reply #13 on:** September 10, 2015, 09:03:38 AM »

Take out 5%oil and add 5% ether. kerosene in itself adds to lubing the engine . we only run 10% in the latest racing engines once u get a setting u should not need to play with the comp until it Worms up ,open the needle 1 turn and finger chock. start flipping ,u will fell the diff as it gets ready to start . it will sound terrable at first put your finger over the ventyri and block about 3/4 of it . as the engine picks up remove your finger and turn needle back in. then fine tune if necessary

it is best to start on the soft side and then add more comp as needed, if u start out with too much comp u can cook the engine in one flight. with the team racers we have a shut off and at the first hint of over compression we shut it off

this is all done after u put your flying prop on. hope this helps

frank mccune · « **Reply #14 on:** September 10, 2015, 11:08:25 AM »

Hello Bob:

MIRACLES HAPPENED TODAY! Time to purchase a lottery ticket!

I went out to play with the MVVS and G 20/.15D today and they both started on the fourth flip!!! OMG!!!!!!!!!!!!!!!!

Here is what is different today. Perhaps it makes a difference"

Temperature is 73 F

Humidity is 90% and it is raining.

Place 4 drops of fuel in the venturi. Increased the compression a bit on the MVVS but did not change anything on the ST from its last running settings. Both roared into life on the fourth flip. I did this until I found it no longer amusing. Lol I did not connect the fuel tank on either engine but I will at a later date. If it starts on the prime, it should start when the fuel line is connected correct?

One strange thing did occur however. I placed a few drops of Husky Air Tool Oil from The Home Depot in the MVVS and the engine would fire each time I flipped it. After about 5-6 "starts" I stopped to ponder why this is happening. I was taught that air tool oil was formulated NOT to combust under compression! This is also known as Dieseling. I saw the results of plugging a jack hammer into an oxygen and it was not pleasant. The jack hammer was blown into many bits of shrapnel. This was called Dieseling.

In any case, the Gods have smiled on me today! Lol

Thanks for all of the help!

Frank McCune

Air Ministry . · « **Reply #15 on:** September 10, 2015, 08:57:22 PM »

Indeedski , in Siberia we have to use oxygen to start ! .

You want to be carefull with that EEE Lectric Starter . Flooded - you can bend a con rod . even without a lectric starter .
A olde Pommey trick was to wrap a rag dropped in boiling water round the engine , for a C O L D start . ( winter cold ) .

Generally fireing it on the prime before connecting the tank wil get the Comp setting before flooding it .

Carefull of them rods . My PAW .09 took a hhalf hour plus to fire up . In desperation I started it on a prime and keet opening the Needle
a half turn Ea Attempt . At FIVE turns it started . ' the book ' said three turns . Wouldnt Go on Three Turns . Hence the prolonged attempt.

And a big prop gives a bit of flywheel to warm it up . S.J. used a ' warm up ' prop to get settings , I think .

May have them there G20 screws , if your not after perfect ones . Sunny today - spring has sprung . in the day anyway . Matt.

Author Topic: What is your starting drill for a Diesel both hot and cold starts? (Read 3902 times)

frank mccune

What is your starting drill for a Diesel both hot and cold starts?

Motorman

Re: What is your starting drill for a Diesel both hot and cold starts?

frank mccune

Re: What is your starting drill for a Diesel both hot and cold starts?

bob whitney

Re: What is your starting drill for a Diesel both hot and cold starts?

Les Akre

Re: What is your starting drill for a Diesel both hot and cold starts?

frank mccune

Re: What is your starting drill for a Diesel both hot and cold starts?

bob whitney

Re: What is your starting drill for a Diesel both hot and cold starts?

qaz049

Re: What is your starting drill for a Diesel both hot and cold starts?

bob whitney

Re: What is your starting drill for a Diesel both hot and cold starts?

frank mccune

Re: What is your starting drill for a Diesel both hot and cold starts?

bob whitney

Re: What is your starting drill for a Diesel both hot and cold starts?

Les Akre

Re: What is your starting drill for a Diesel both hot and cold starts?

frank mccune

Re: What is your starting drill for a Diesel both hot and cold starts?

bob whitney

Re: What is your starting drill for a Diesel both hot and cold starts?

frank mccune

Re: What is your starting drill for a Diesel both hot and cold starts?

Air Ministry .

Re: What is your starting drill for a Diesel both hot and cold starts?