Mills Brothers 1.3 Diesel

[Graham Meek]

Can anyone who has built the above engine from the Motor Boys drawing help me out.

I have a retired Anaesthetist  friend who is trying to build this engine and he has asked me to look through the drawings.

I have been looking at the Venturi detail, it says to drill through #32 (0.116") drill and flare out each end at 8 degrees inclusive. The Venturi is tapped 1/8 Whitworth to take the spray bar which means there is no venturi. Is the #32 a typo error, or is the spray bar wrong?

There is also no sizes given as regards the fuel outlet hole size on the venturi centre-line. Should this hole be just on the engine side or all the way through?

My best regards
Gray,

[Jasonb]

Gray, I think the idea is to screw the spray bar into the venturi before it is drilled, solder and then drill the venturi #32 which will also drill through the spray bar. This is for the Built up carb not the cast one.

Do you have access to teh build that was published in MEB?

[Graham Meek]

Hi Jason,

Thanks, that would make sense, only having A4 copies of parts of the original drawing I am probably missing some vital information contained in some notation not shown on the A4 copies.

I did not know this engine had been published on MEB, I have not considered joining this site as generally I am not into building published designs.

My best regards
Gray,

[Ramon Wilson]

Hi Gray - how are you?

I can't find any ref to this engine either in the Motor Boys book or on the MEM site. Doesn't figure under 'Plans' nor 'Projects' on there and it's not in the members area either.

Have I missed something somewhere 

Can you point me in the right direction or post the drawing up.

Regards - Ramon

[Jasonb]

Check your e-mail Ramon for relevant drawing

[Graham Meek]

Hi Ramon,

I hope you and Sue are OK?

It is that time of the year when my health usually takes a nose dive, just after the Flu jab, but touch wood, this year has not been as bad as previous years. Each day I am seeing a steady improvement so I am not grumbling.
I have been enjoying your recent post, and learning a few tips along the way. I am convinced my friend has sent these drawing as a ruse to get me to make a Mill's, he has been on about this engine for years. Unfortunately with the work on my Fiat tractor and my own 4 stroke diesel I already have too many things going on.

Take care,
Gray,

[SandCam]

Hi Guy's,

I believe the drawings and build article for the Mills 1.3 were published in 'Model engine Builder' magazine... issue 1.
I don't subscribe to this at the moment but I believe Ramon does/did.

Perhaps he has a copy of that issue.

Hope this helps track down things.

best regards and good luck.

Sandy.

[Jasonb]

Yes drawings and a long build article were in the first issue of MEB.

[GailinNM]

Here is a link to the general arrangement drawing on Model Engine News website showing the needle valve arrangement.
Gail in NM

[Ramon Wilson]

Hi Gray - yes we are both fine. I've yet to experience the pleasures of a flu jab - hope that recovery improves dramatically.

Thanks for the drawings and text Jason. Strange it's a Motor Boys drawing but not apparently on MEN.

It would 'appear' you are correct in that the spray bar is soldered into the venturi then the venturi is through drilled. I say 'appear' as though it does draw attention to the fact "Note we have not drilled the #32 hole right through yet" it goes on to explain the soldering then setting the needle in it's holder omitting, as far as I can find, any reference to further drilling the venturi through.

I recall repairing a Mills .75 (replica) about a year ago. The venturi had an enlarged section where the spray bar was located. The (ali) spray bar was removable in one piece and had a nut on the top side to keep it captive. Larger in diameter than the venturi bore it had been drilled through in situ to leave very thin (and weak) walls. Another option Gray?

Regards - Ramon

[Maryak]

Hi Guys,

The 3cc OB Bolton diesel has a similar arrangement below is a detailed drawing of the fuel system.

Hope this helps

Best Regards
Bob

[rklopp]

I can confirm that the Mills 1.3 venturi per MEB/Ron Chernich plans is built by screwing in the spray bar, soldering it top and bottom, and then drilling through the venturi throat.

I built two, and they are about my favorite engines. They are super easy to start, and not terribly loud.

[Jasonb]

Gail's drawing is for the version with the cast venturi, Gray is talking about the built up one. The idea is to make the spray bar as one so that the needle will be in line with the seating rather than two pieces top & bottom of teh venturi which will be very hard to get to line up

I think Ron did the drawings and 18 page build article as a special for the first edition of MEB mag. Engine is said to be based on the Mills Brothers ( Model Engineers) "Mills1.3" which is based on teh French Allouchery 1.25cc

[Graham Meek]

Hi Jason,

A picture paints a thousand words as they say, all has now become clear.

I did wonder if anyone has seen the "Throttled" version? Some photographs and drawings of this would be handy for use on other Diesel engines.

My best regards
Gray,

[tedsmith]

hi can any one help me with a full set of drawing for ron chernich mills 1.3 Diesel engine, which I wish to to fit into my
DH9A plane hope to hear for some body soon regards ted smith .

[Allen Smithee]

In the mid 70s when I was a schoolkid I had Mills 1.3 which I grafted an Enya 09 throttle onto (the local model shop offered the carb for peanuts and no one told me it was sacrilege) with a sleeve I made in the school machine shop. It didn't do much - any setting other than fully shut had no effect on the power at all, and so it ended up as a 2-speed throttle system with the low speed set by the airbleed screw!

This was done as part of the process of converting my 2-year-old DH9a (Eric Coates plan) to take a single-channel RC set I had been given. It flew very nicely until I fitted a bigger fuel tank ('cos it was RC now, so needed a much longer engine run, obviously) and was enjoying it so much the rubber band on the escapement ran out of turns and it headed off south from Radio Hill at Chobham Common, climbing like a good'n. The model, the mills and the escapement are probably still somewhere between Longcross, Guildford and Woking (but probably no longer airborne)...

AS

[b.lindsey]

tedsmith,

As was noted earlier in this thread the plans should be available if you can find a copy of MEB issue #1. I would assume that these may still be under copyright and therefore the forum cannot condone copying or supplying them in any form of the site. Even if they are now in the public domain, we would prefer that members at least be active on the forum prior to asking for "freebies." MEM is a forum for the purpose of sharing ideas, and providing help with specific issues as needed, but it is not intended to be for the purpose of simply providing access to plans which are available through other sources.

Regards,
Bill

[fumopuc]

I have bought some older copies from MEB during the last weeks. IT is USD 6 each for the PDF file and Toni has sent the files in on two hours after ordering via the MEB website. Great and quick service.