Motorboy

NEVER!!!! NEVER!!!! NEVER!!!![X(]

Use woodblock with hole to fit cylinder and fasten in vice careful and turn crankcase from cylinder.

Jens Eirik

TimC

I drilled an 11/16 hole in a small block of wood, then split the block into two pieces centered on the hole. I clamped the cyinder/block in a vice and the cylinder screwed right off (thanks Jens). Using the same block to hold the cylinder, I used a wood dowel to tap out the contra-piston from the bottom side. After using steel wool to polish everything up, the contra-piston is still a very tight fit in the cylinder. I sure hope it was meant to go out through the top. There are some scrape marks on the side of the contra-piston.

Motorboy

Very well done!!!!

Contrapiston must be tight in bore, but can be moved up by compression. Do not grind with emerypaper or do not with scrape marks if you can not feel marks with finger. Smear oil at contrapiston and in the sleeve, then mount the contrapiston. Remember , smear all parts before assembly the engine.

Jens Eirik

TimC

Thanks for all the help on this cheap little engine. I've learned some of the basics, and would now like to buy a better engine and get into diesel power. I have one last question: I can move the contrapiston down with some resistance with the compression screw. If I pull off the cylinder and try to push it back up with a dowel, it wont move. Is this too tight?

After searching the on-line hobby stores, I've found that there is hardly anything available for diesel users. I don't remember seeing any engines in any of the many hobby shops I've been in. Is there a U.S. on-line hobby shop that sells diesel engines and accessorys?

Jim Thomerson

The contrapiston test is this: If it is too loose, back crud will come out around the compression screw while running. If it is too tight it will stick as the engine warms up and you will not be able to back off compression. I've been know to work on a contapiston with 600 grit sandpaper.

Someone will give you Carlson and Eric Clutton's contacts. Carlson is on line to some extent, but Eric is not so far as I know.

sigrun

Eric Clutton wrote a fairly lay orientated thin approx. A4 sized booklet entitled "All you want to know about Diesels" - or of similar title. Fairly general and simple, but useful if you've not run diesel before. Eric's a source and has aquired status as a local diesel guru in the states.

Carlsons, as Jim mentioned supply all manner of imported engines. Also a good local place to source whatever you want. Just throw the name into Google should turn up their site.

Tuning a diesel is easy once you know how, but is a bit of a black art which is better demonstrated than explained. Without getting tutored in its finesse, most tend to overcompress. See if you can find someone local who knows diesels to show you. I'm sure any enthusisat will only be too happy to pass on his knowledge to anyone interested.

If you want a reliable, powerful and affordable contemporary diesel for which you can still get fantastic service and parts, one word. [link=http://www.eifflaender.com/]PAW[/link]. Nothing but praise for the Eifflanders, vale Jochim aka "Gig". Not only are their engines good, but in my personal experience, they honour what they advertise when it comes to service. Can't praise them highly enough.

Alternatively you can source them from [link=http://www.justengines.unseen.org/paw.htm]HERE[/link]

Go ball race if your budget extends to it. Much nicer to use, easier starting and noticably more powerful. Once youve used BR diesels, PB won't get a look in except for novelty value or specific task orientated use.

Someone else might better be able to answer your question about the contra-piston. TMK I know of no reason it shouldn't move in either direction with equal ease without excessive force. I don't believe the bore is tapered or the contra-piston chamfered.

cheers

sigrun

TimC

sigrun, how do the glow/diesel conversions work out? I have an idle .46FX that would be a good candidate. How much weight would a diesel conversion head add to a glow engine? (OK, a few more questions. )

sigrun

Not really the person to ask on this one. I've never bothered with them. Plenty have, so you'll get answers. Davis conversions might have something to offer. But practically speaking, I suspect a 46FX would chew the $$$ juice a bit harder than you'd like and I don't really see it being a practical conversion given its construction, porting, timing etc. Just a guess, there would be better glow candidates for conversion...??? Of course, I might be entirely wrong about the 46FX's suitability. investigation will reveal.

Weight (insignificant) per se isn't ordinarily an issue in conversion, especially so in this capacity.

If it were my first diesel, personally I'd start with a positive experience working with a reputable known.

AMB

Sigrun The FX is a decent conversion Mr Davis over the years has done many OS conversions SX. SF, LAs now the AX series, He is quite careful to select engines that make good conversions and with good reason since he does not desire any ill comments that reflect on the quality of his product I am sure his thinking if does not work well "quilt by association" as far as the OS 46 goes the ASP 46 is a knock off and works on that one too. I use his heads on my irvine 46 and 53s fuel economy is good at least 5 or 6 minutes an oz. I see no reason why the OS 46 would not be similar and he does state big increase over glow in running time and his conversions bear this out, similar results with Fox, Kand B, and others.
intresting footnote is Davis has made conversion heads for just about every model OS from FPs foward I have an OS FP 10 with his head great runner, Just when things I guess going well OS sells lots of FXs and demand for heads goes up, He makes a bunch builds inventory and then OS pops the AX series 4 bolt head of course, Turns out to be a decent engine, you guessed it now AX heads
martin

Hobbsy

My Feedback: (102)

http://www.rcuniverse.com/forum/m_1871573/tm.htm

Here are the results of my LA .46 conversion, 12x6 three blade 8,800, 12x7 ProZinger two blade 9,000. The .46 FX would be an excellent. My LA .65 conversion turns a 13x8 three blade at 9,000 and runs as smooth as a sewing machine. I doubt that my PAW .60 could manage 7,000 with the 13x8 three blade. It might fool me though.

AMB

Dave and Sigrun davis has always "leaned toward OS as well as Fox Kand B , supre tigre " as rugged well made engines not to say the others listed do not work well Back a few a few years ago when I expanded the plane and engine interest. The irvine 46, and 53 were obtained simply because for a quality motor it was quite a bit less than OS when the $/GBP exchange rate was about 1.4 after using the irvine40 diesel, gave then a shot since davis agreed to make heads for them If he did not I would have sprung for the OSs. As you all know the LAs are a good strong basic engine simple and used in many traiiners but no barn burner the real surprise came as a diesel
conversion and a plain bush engine at that the irvine 25 and 36 and old irvine 40 were not considered a commercial reality so AJ made heads for me on these , the MVVS 40and 61 he (davis) supplied heads for, even though MVVS 61 had a factory diesel head the Davis one is a far better product. Also the irvine 40 diesel had the tendency to drop its contra every now and them so he made heads for them
tons of them out there so now they live again
Mr Davis on several occasions has spoken to both OS and Irvine to make a factory diesel but it went nowhere and least Enya took the jump.It would be in his interest if they did since he does make diesel fuel

And to you guys down under there, maybe your model associations coud lobby for relaxing import restrictions the premix stuff would be useless to the druggie makers
"
IMPORTANT NOTE TO NEW MODLELERS" IF YOU ARE JUST STARTING AND HAVE NO ENGINES YET GLOW OR DIESEL

consider a PAW diesel no cross over learning process from glow very easy to use get it with the muffler ring, have the seller install
it since the cylinder assembly most be removed and has to go back in same orintation even if a few bucks to do so. My first engine
was a drone diesel U/C learned an flew on that one martin

TimC

Today I put together a little 2 oz. tank with a stopper and line good for diesel. I installed a 9x4 prop on the engine, primed it a gave it about 200 flips trying to start it. Nothing. All this time I was advancing the contrapiston about 1/8 turn each time. I also tried priming with pure ether and it still wouldn't pop. I took it apart and remembering my friend said it was running when he put it away years ago, I returned the contrapiston to where it was when I took the engine apart. I primed it again and hit it with my electric starter. It fired up and after some needle adjustment, ran steady until the tank was empty. I guess I'm going to have to learn that diesel flip. Now my hands, clothes and test bench reek of diesel fuel.

Motorboy

Well done!! You has much to learn how to start the engine. Next time you will flip the engine, flip fast the propeller because the engine must comprime the fuelmixture fast and develop more hot enough to ignite fuelmixture.

Jens Eirik

AMB

Tim C these engines (at least mine had some strange quirks) I could not hand start them (not all) After a few runs using the electric
starter they now hand flip with 1 to 6 flips and you do have to use a fast snapping action. One the bigger engines Irvine 53 conversions
I still use the starter just seems a little safer they will on occasion kick back hand starting but so do glow engines. Just a couple of examples my Irvine 25 conversion and the ST40. Mr Davis states to use an electric starter on his conversions and my guess is a safety
issue I have had very few times when I could not hand start his conversions/ My ST90 Davis head would not crank over with the wimpy
starter I had so the chiclen stick did its thing martin

TimC

I guess this also shows that diesel fuel will last a long time. This old can of Red Max was probably 10 years old and had been opened and about 16 oz. used. It still has a very strong ether smell.