The Home Machinist!

Gentlemen,

Is there a book out there that one of you might recommend for someone interested in designing a small diesel engine? Something that would detail design standards, common practices and power calculations.

Not to build a model per'se, but a model sized engine to fit into 15" gauge or maybe 7-1/2" gauge locomotives for a true diesel-electric drive.


Thank you for your time,

Curtis F.

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16 Years of SolidWorks experience...now I feel old.

Hi Curtis



I doubt you'll find anything. My research has got down to a 9.5cc single cylinder in SIC, named DUX. There is a gentleman in Oz with a single around 65cc, a twin around the same size in Oregon. I also came across a paper from Ricardo on the design and operation of a 100cc single and there is some work happening at the 49cc mark for mopeds.

The smallest other commercial multi-cylinder diesels start around 200cc to 250cc per pot - Yanmar, Kohler, kubota etc. As far as I can tell there is a bit of void around the 50cc to 200cc mark and even fewer multi-cylinders with pots around that size which is where a 7.5" gauge loco would be. For 15" gauge, the yanmar or Kohler range would suit. In the UK, smaller car diesel engines have been used.

I initially wanted to do a 2 stroke V16 EMD style but after some work, the torque flow would be way too high. After various iterations I am at a straight 6 4-stroke. In order to make it sound like an EMD, the engine controller (did I mention I want to use an ECU - have done them for work) will synthesize the low end in tune with the engine and drive something to be determined.

This is for a 7.5" gauge UK class 59 or 66 (I moved from the UK to west coast canada a few year ago).

Not sure if that helps, but I hope it's a start.

Veronica

In most large scale diesel outlines, you will find the little 3 cyl Yanmars and such, pulled from the likes of mowing machines and lawn tractors. At about 20 HP they do very well in what I have seen.

I cant imagine spending years, trying to build a motor.

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Big Dave

Be Alert! The world needs more Lerts.

http://www.smokstak.com/forum/showthread.php?t=50410

there are youtube videos of a 2 and a 4 cylinder that don comstock scratch built

There's a limit to scaling down a diesel cylinder, a point is reached where the thermodynamics just won't work. The heat loss to the combustion chamber surface becomes too great for fuel to ignite by compression. The tiny volume of fuel to be injected poses problems too. The "Diesel" model airplane engines are compression ignition, but the fuel is alcohol/nitromethane/castor oil, not injected into the cyl. but drawn in w/the air. SO, not a true Diesel...Pity, one of my big dreams is a 1/16 scale 14A D8 Cat...

http://www.youtube.com/watch?v=E4-fOw6vr34&NR=1

Looks like this one has a few issues, but it is running.

Veronica,

Thank you for the information.

My apologies for taking so long to respond (I hope you're still around to read this). After there were no responses for a couple of weeks, I forgot to keep checking back.

This project is on a back burner, but the burner is still lit! I've seen several gauge 1 (45mm) engines out there with converted model airplane engines to built "diesel"-electrics, so I know it can be done in the larger scales.


I'm be very much interested in hearing an update on any progress on your EMD straight 6 and class 59 / 66 loco. At 70 ft (21.4 m) long those are some fairly good sized engines.


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I know guys that have spent 30+ years building a steamer. Why? Because they find it challenging, rewarding and fun. It's a hobby.

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joneg, J Tiers,

Thank you both for the You Tube links. More leads to follow.

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ronm,

You bring up some very good points. Like with a steam engine, "you can scale fire and water." While compromises must be made, it can still be a load of fun.


Cheers,

Curtis F.

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16 Years of SolidWorks experience...now I feel old.