Australian diesel loco in 5? gauge.

[Four stroke FredParticipant @fourstrokefred]

Working scale model of the type of loco used for shunting in Queensland.

[Four stroke FredParticipant @fourstrokefred]

This is a scratch built model scaled up from works drawings, photographs and sketches. It is powered by a home designed and made three cylinder water cooled petrol engine with side valves and cross flow head. The gearbox has two forward and one reverse gear. The engine is equipped with a gear oil pump, a petrol pump, water pump and fan and Hall effect ignition system. The cab is fully detailed and there is a full interior and exterior lighting system and a workING electric fan in the cab ( there was no air conditioning on the full size loco.

[Four stroke FredParticipant @fourstrokefred]

[HopperParticipant @hopper]

Nice work there. I bet it sounds good too. Triples always do. Cross flow side valve is a bit different but would seem to simplify porting im guessing?

[Roger BParticipant @rogerb61624]

Excellent, One of the rather rare IC locomotives powered by a home built engine.

[I.M. OUTAHEREParticipant @i-m-outahere]

That looks fantastic !
How long did it take to build ?

I am curious as to the carby design – is it butterfly or slide control ?
Am i correct in thinking that have seen a picture of this loco in AME – colour looks familiar !

[Perko7Participant @perko7]

Fantastic work, really well executed. I particularly like that you have maintained the correct scale proportions of the loco body and associated fittings. Can I ask what you used for the final drive to the axles? Also it seems like it might be a bit light for good traction, have you needed to add any ballast?

I am making a Qld Railways DL Class 2-6-0 diesel but don't have the skill to make my own engine so have used a 25cc Stihl brushcutter engine. Had to make a new inlet and exhaust so it would fit inside the engine compartment. Uses a tumbler reverse for forward/reverse and an angle grinder head for the final drive. Some photos in my album but still lots more work to do adding the finer details. Currently making handrail knobs but slow progress as we are moving house so most of the workshop is currently in storage .

[Howard LewisParticipant @howardlewis46836]

A really super job, overall! Fantastic!

But am intrigued by the choice of cross flow side valve configuration for the engine. Is the compression ratio low?

I was always led to believe that the change to non cross flow side valves was because of the tendency for cross flow (T head ) to have pockets of end gas that promoted knocking, when compression ratios were increased to obtain more power

Howard.

[Simon CollierParticipant @simoncollier74340]

A truely impressive model. I am often underwealmed by diesel models with electric motors and battery, but to design and make the engine yourself for a highly detailed model is quite something. I hope I can look forward to a write up in AME and a front cover picture.

[Four stroke FredParticipant @fourstrokefred]

Thanks for all those who have shown interest in this project. A little more information on aspects of the loco. All wheels are driven and 1:1 bevel gears are used to transmit the power to the four axles. Also all wheels have compensated braking.The engine shown is actually the second engine that I Have built for this model with first being an 80cc OHC four cylinder unit but felt that this was perhaps to “ sporty”. I wanted an engine that would produce power at low revs and fit with in the out line of the body. I am not interested in building a detailed model to pull masses of people – just the driver will be sufficient. The cross flow head does not have an efficient combustion chamber but this engine is 150cc and even being inefficient should produce enough power. The cross flow arrangement allows the carburettor to be on one side and exhaust on the other and the engine to remain on the centre line of the loco. I did use this type of engine on the model Saunderson and Mills tractor and was pleased with the results. I do still have some work to complete on the loco and engine and hope to have that completed soon. If I can find a photo of the other engine I will post it.

[Four stroke FredParticipant @fourstrokefred]

[Four stroke FredParticipant @fourstrokefred]

I could not find the photo of the OHC engine but have included extra photographs of the 3 cylinder engine and crankshaft. The later “ carved” out of a billet of 4140 steel. The other photo shows some of the detail in the bogies.

[Howard LewisParticipant @howardlewis46836]

Superb work, and the design work that preceded cutting metal.

You have good reason to be proud of your work

Howard

[HopperParticipant @hopper]

Cool stuff indeed. I have a soft spot for side valve engines due to vintage Harleys I mess about with. Never seen one with valve cutouts in the top of the piston though! Borrowed from an OHV motorbike engine?

Looks like she should have plenty of low rev torque at 150cc.

Edited By Hopper on 30/07/2020 00:19:42

Edited By Hopper on 30/07/2020 00:20:07

[Four stroke FredParticipant @fourstrokefred]

Good Day Hooper,

Thanks for the comments. You were correct in relation to the pistons. I bought them at a Cheltenham (UK) swap meet when I was on holiday in the area and was told that they were Honda 50cc of the 1960s. I couldn’t resist them as they were for sale at £5 each or all 4 for £15 and that was complete with rings and pins. I didn’t know what I was going to use them for and later found out they were all different sizes ( for rebores)! The cut outs on the pistons match up with the gas flow from and to the valves. The engine just of “grew” around them!

[HopperParticipant @hopper]

Good stuff. Sometimes you just know something will come in handy one day.

[HopperParticipant @hopper]

Good stuff. Sometimes you just know something will come in handy one day.

[Ron LadenParticipant @ronladen17547]

Very impressive Fred not only in designing/scratch building the loco but to do the same and design and build an engine for it is even more so.

Its obvious from the pictures the level of thought, design and quality of engineering that has gone in to it you should be very very proud of it, excellent it really is.

Would you be so kind and post some video of it when you take it to the track, would love to see and hear it running.

Ron

[Paul KempParticipant @paulkemp46892]

Love it, very nice work.

Paul.

[Ady1Participant @ady1]

wow

[Four stroke FredParticipant @fourstrokefred]

I have managed to find a couple of photographs of the 4 cylinder engine . Excuse the quality but I had to photograph the computer screen onto the iPad but it gives you some idea of the finished product. The engine was built in 1997!

[Roger BParticipant @rogerb61624]

That's an impressive engine. Did you run it much? Is that a fuel or oil pump next to the carb? Is the camshaft chain or gear driven?

[Four stroke FredParticipant @fourstrokefred]

I did run the engine on a test bed and the block is a gear oil pump that feeds the main and big end bearings. The cam shaft is driven by chain 1:1 with a gear reduction of half engine speed from the crankshaft. The Engine has a pent roof combustion chamber with valves on one side and spark plugs in the other. I used conventional points/ coil ignition and added a governor on one end of the camshaft. Cast iron liners are used.

[Ron LadenParticipant @ronladen17547]

Fred,

There was mention of could it be light for good traction but I cant imagine that, I would have thought the loco has more than enough all up weight for good traction. Have you a finished weight, just interested what it comes out at.

Ron

[Four stroke FredParticipant @fourstrokefred]

The promised casting session didn’t take place due to the inability of the brain cells to visualise the correct shape of the core. Due to a seniors moment or total brain fade I had made the core a lateral inversion of what was required. I needed to make a mirror image of what I had previously made. As they say if you haven’t made a mistake you haven’t lived. That mistake has now been rectified and I hope to try to cast it over the weekend. Yes fingers are still crossed.

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