Seems to me that noone really knows how to make an engine, I performed a search that worked, came up with a .edu site of some guy telling some details on how to make a diesel. I'll post both the google search and the direct link. Anyone made their own? I want to make my own engine eventually (as in decades from now), I don't know what kind yet though.

http://archive.dstc.edu.au/BDU/staff.../build.html#A1

http://www.google.com/search?hl=en&i...ngine+building

Apparently you don't come here often, here are some of my engines. both total builds and restorations.

Do a search on the Vivell .09 and read the thread titles below

Next Project
Vivell .09 Diesel Finished!!

[link=http://www.modelaircraft.org/site/product.aspx?id=0BF5610322F5460EB875963D94E78EDC&d =0BF5610322F5460EB875963D94E78EDC]Motor Boys book[/link]

See link.

Way cool! What equipment do you use to make the parts for your engines?

Just this little lathe and mill.

Wish I had a shop that big! And with all those tools! Oh well, I've got time. BTW, I've been working on a design for a motor. It's just to practice my modeling abilities, and of course it's just for fun. Closest thing to actually building one. I figure I'll work on the design of it here, and upload the file of the finished design. Hey, maybe I can get the general design down, and it'll just be an open-source engine design for anyone to use. It's a twin, mostly because it's easier to design it that way. I intended it to be a single, but, you know how it is. Just tell me what to do, and I'll change it so in theory it would work, just not down to every last detail. Here's a ghosted view:

First problem I see is that you have the cylinders in line. A 2 stroke engine needs to fire simultaneously or have the crank cases isolated form each other. If they are isolated you need intakes for each one. You under a misconception thinking a twin is simpler to design, a single is by far the most advantageous to learn on. Before you design an engine you need to get the principal of operation down. It is much morte then pistons in cylinders, and much more then I can write here. Try building from a casting kit first.

I can see the hole for wristpin in the piston at 3D drawning means thinn wristpin will be weak and unuseful for the diesel engine.

Jens Eirik

" Seems to me that noone really knows how to make an engine..."

Hmmmmm.... thems there are fightin' words son.

It's not surprising that responses to your post have been luke warm to say the least. FWIW, [link=http://modelenginenews.org/index.html]Ron's Site[/link], (the edu site you refer to above) is probably one of the most complete resources of model aircraft engine building that you can find on the web. Take the time to browse Ron's site and I think you'll have a different opinion.

Jeesh... if what you say is true, then I must have been dreaming when I thought I built these.

-Joe

http://www.geocities.com/joby1967200...-1/NGEZ-1.html

Ranjit Phelan of australia is one of the worlds top pylon racers and he builds his own motors. He was the only competitor at the last world champs to have built his own model and motor, with which he placed 4th. Also all of the Australian team used Ranjits RPM engine and the team took 3rd place. There are some very keen engine builders throughout the world, and my hats off to them .
Stewart

Joe,

The engine on the right looks like an EmBee or a PMC Imp. I am getting ready to build the Imp and wondered if you'd done any timing changes to it.
The other looks like the Lil' Dragon in diesel drag. Nice looking work!

Randy,

Thanks for the compliment!

Actually... the engine on the right is a Mark Lubbock designed "Midge" (It's an unofficial Motor Boys offering. ) It's a real sweet runner and fairly easy to build.

You're actually pretty close on the other one - it's my take on the EZE engine series by Tom Crompton (which of course is an off shoot of the Little Dragon series). I have done a few things different than Tom's design so I feel rather comfortable calling it my own. More details can be found on the link I provided earlier.

Funny you should mention the Imp... just last night I was looking at Ron's site and that one caught my eye. I thought about designing something along those lines as my next project. Where'd you get the plans? If they're readily available that may be the best route to go. Ron mentions that the Imps had a replacable "timing ring" of sorts that alters the cylinder sleeve height and subsequently the port timings. (7/64, 1/8, and 9/64") - Is this what your plans show?

-Joe

Joe,

Perhaps I spoke too soon. The plans aren't available yet, just now getting the bugs worked out and I don't really know if Ron plans on releasing them or not. I have them because much to my surprize and pleasure I was invited into the MB group. I know there are plans afoot to update the MotorBoyz book, but I have no idea how long that might take.

Gotcha, say no more.


Well congratulations... that's quite an honor!

-Joe

Hi Joe,

Thanks, I'm pretty geeked about it myself.

Congratulations! A signal honor indeed to be counted among such a worthy group!

Ok. I'm really interested. What would I need to get started on an engine like ProBroJoes? If it's not considered a beginners engine (well, assuming there's such a thing), what's a good place to start? Doesn't have to be combustion, if a sterling engine or steam engine is a better place to start, I'm game. I browsed around the internet yesterday, and it seems some people like this inexpensive chinese made lathe... accurate to .001" after tuning. I imagine pistons and sleeves need to be even more precise than that. What do you do to make them fit nicely?


Seems I found a great resource:
http://modelenginenews.org/index.html

That link has all the information you are looking for including beginners projects in the last couple months. I would just start reading all of the engine construction articles starting with the beginner engines. You will learn technique and see what kind of equipment is needed.

Greg

How precise are the lathe are not very important, it is lapping technic who make the engine more precise + skilled mechanic do it better.

I has used worned and old Myford ML10 when i maked the engine, used sandpaper to trim parallellism and smooth surface at crankshaft and lapped cylinder/piston to fit. Used adjustable reaming tool for crankshaft bearing. Not problem

Jens Eirik

lapping technique... new term! Hmm, I'm guessing it's kinda the equivalent of figuring a telescope mirror, except you're figuring a piston, and you're not using glass with grit, or a focault knife edge tester... ok, not a terribly close comparison! I don't think you'd need to be concerned about the wave accuracy of a piston.

Does anyone have a source for the article or plans on the ML Midge? I can't find them offered anywhere? I wouldn't mind trying one of these little engines.

Thanks
Tom

http://modelenginenews.org/index.html click on +Engines, then click finder. scroll through the list till you hit M.L. Midge, there's lots of stuff on it. I can't link directly for some reason though. I right clicked and tried to get page info... just gave me the same url I typed.
maybe I should have just said, "I don't know where to look... help! All kinds of stuff out there!

I am using the fine grit for valvegrinding for automobile engine. Shall be dull gray surface. Lap the cylinder until all marks of tool are removed, lap the piston until the piston are entered about half of pistons length. Then smear chrome polish paste at piston and lap in the cylinder inward until piston are stopped. Take out the piston of cylinder. Wash both parts in gasoline, oil in parts. The oiled piston will go easy in the cylinder and without oil the piston will go tight in the cylinder, all are ready. In bottom of cylinder are the piston loose and top of the cylinder are the piston tight means tolerance are right and less leakage while piston are raising to top of the cylinder and make compression.

Jens Eirik

Thanks for the link but what I'm trying to find are the drawings and the write up on it. I know it was in some magazine but I have no way of getting my hands on it. If anyone knows how to obtain them, I would appreciate it.

Thanks
taq

Try e-mailing this guy:
[email protected]

BTW: The only thing really intimidating me about a project like this, is cost of the machining equipment! Hmm, garagesale is in call for, actually, a garagesale has been in call for about 4 years! Boy I've got too much stuff... not necessarily R/C related either.