Can anybody identify ?

[Cboomf]

Hi All !

First post here and I'll start with a question.

Can anybody identify this, I was given it by my father but have no clue what it is, beyond a compression ignition engine ?

I've started to clean it up and hopefully get it running again !

Any tips or advice would be appreciated as well

Thanks

 

[mu38&Bg#]

It's a Mills of some sort. Could be reproduction. I'm not familiar with these older types to be able to tell.

http://modelenginenews.org/cardfile/m75.html

Greg

 

[Cboomf]

Brilliant, it does appear to be a Mills P75 !

Does it run on just normal diesel or would it run on this 'nitro' stuff i hear about ?

 

[Peter.]

Cetainly looks like a Mills I once owned about 20 yeas ago. Mine was quite old then. Can't imagine what you're going to have to do to get the head off and contra piston out.

 

[Cboomf]

From the website above, i see that they have a removable clank case to get the crank out, but i can't see anyway, on mine, that it can come off, it looks to be one solid lump. Of course this may just be because it needs a clean but if it doesn't i cant see how you get the crank out.

 

[Maryak]

1. Remove the compression screw.

2. Pour some kero down the hole until it comes back at you, i.e. completely flood the top end.

3. After say a day of soaking the finned head should be tried to see if it will unscrew from the cylinder, (normal RH thread)

If you look at the back of the engine where the recess is located your photo shows at least one lug in the recess. Probably there are two at 1800.

Spray /soak in kero and then after a day or so make a key to fit the lugs and unscrew the recessed section from the engine body, (normal RH thread). You then have access to the crankcase big end and conrod.

Hope this helps.

Best Regards
Bob

 

[pelallito]

If the Kero doesn't work, see if you can get a product called Kroil. It is a super penetrant. Kano labs makes it.
Fred

 

[tomol409]

Yes- a British Mills 0.75cc Diesel engine Type P as it has no cut-out. Runs on a mixture of equal parts Ether, Paraffin (Kerosene), and castor oil. Dark finish is a special finish and crankcase magnesium. Some cleaners will attack this. Scrub only with a fine wire brush to clean the corrosion. Use a modicum of heat to help free the engine. The outer end of the crankshaft thread is broken off, so to fit a prop and help free the engine, make up a sleeve nut - a nut with a rear extension to fit inside the prop. The thread is No. 4 British Association - TPI 38.5 or pitch 0.656mm.
The prop driver is fitted to a taper on the crankshaft and must be pulled off with an extractor.
Normally fitted with a hexagon prop nut with a rounded end, which is about 7/16 UNF size across the flats. Also missing is the tank top of pressed aluminium, and the clear slightly conical tank of Perspex.
This is reputed when in full working order to be just about the best starting diesel ever so good luck in that if you get it sorted. The compression must be pretty good or it will never work. Diesels also require a very, very quick flick of the prop!!!

 

[Admiral_dk]

I do not know about the kerosene or penetrating oil as first step (no harm), since the most common reason these oldies are solid seems to be that the Castor oil has hardened to varnish and the most effective cure is heat and you don't want hot fumes from kerosene or similar.

Use a heat gun (air) or an oven and heat to about 100 degrees Celsius for 2-25 minutes to loosen the varnish and use some soft jaws so you don't make any marks.

Ron recommends soaking the engine in ATF (Automatic Transmission Fluid) for a few days as a good method too.

Careful not to twist the conrod unless it can't be avoided.

 

[Cboomf]

Thanks for all the info, its not seized at all, it all comes apart nicely except the crank case, its all still well lubricated inside. The carb needs some work, and the compression head is stuck in the lining but nothing some persuasion wont sort out, then some juice and see if she goes. Its good to know its a 4BA thread on output. My intention wasn't to put a prop on it but a flywheel and run a generator.

Last question, can you buy the fuel ready mixed since i've no idea where to get ether from, the paraffin and castor oil is easy but not the ether ?

 

[mu38&Bg#]

Fuel availability will depend on what part of the world you live in. What is the application for the generator? How will the engine be cooled?

 

[Cboomf]

To be honest I hadn't really thought about cooling

I was thinking about building a small "diesel"-electric loco for 32mm or 45mm, just for fun, or experimenting with running an oscillating engine from the exhaust ???

But for starters I'd love to just see it running.

 

[tomol409]

In the UK in my early days of running diesels, I was able to buy ether at the local chemist shop without questions. Now regulations make it very difficult. Ready mixed fuel is easily bought here - the two main brands being Model Technics and Southern Models. Ether is necessary in the fuel to lower the flash point, but I have read recently that a mixture is sold for easy starting reluctant car engines which contains ether and could be used as a base.
When used with a propellor, this disintegrates the exhaust and disperses it rapidly. You will find these fumes pretty noxious when the engine is used with a flywheel as they hang around. A small fan would help this.
The head is screwed on, so use a strap wrench and heat to loosen it and prevent damage to the fins, not the usual modellers favourite tool - a pair of pliers.
The large nut under the carb is No 0 BA which is exactly equivalent to 6mm x 1mm pitch, except that the thread angle of BA is 47and 1/2 degrees as against 60 degrees for the metric one, but this is of little consequence. This nut is to hold the top of the tank on but if you are using a separate tank, it need not be disturbed.

 

[Cboomf]

Cheers tomol409, I will get some of that Model Technics diesel stuff

 

[ShedBoy]

I never really try to help with these can you identify this questions but I reckon I have the exact same engine along with a larger version, I got them as an added extra when I bought a Cox .049 engine off eBay. Same condition full of goo. I was going to drop it in the ultrasonic cleaner to see if this helps.
Brock