Irvine Mills .75 replica

This is a cool litle engine i want one

I have an original English Mills .75. Sadly, the Irvine copy doesn't have interchangeable parts and original parts are very rare indeed.
Grosvince, if you are ever tempted to dismantle the engine (I'm not encouraging you to do so) I would appreciate it if you could take measurements of the con-rod so that I can compare them. Irvine parts are still available to some extent.

Rod.

Oldenginerod wrote:I have an original English Mills .75.  Sadly, the Irvine copy doesn't have interchangeable parts and original parts are very rare indeed.
Grosvince, if you are ever tempted to dismantle the engine (I'm not encouraging you to do so) I would appreciate it if you could take measurements of the con-rod so that I can compare them.  Irvine parts are still available to some extent.

Rod.

As I don't know how to remove cylinder head and cylinder with no damage on this engine, I would prefer not to dissassemble it. Sorry.

Vincent

Grosvince wrote:

Oldenginerod wrote:I have an original English Mills .75.  Sadly, the Irvine copy doesn't have interchangeable parts and original parts are very rare indeed.
Grosvince, if you are ever tempted to dismantle the engine (I'm not encouraging you to do so) I would appreciate it if you could take measurements of the con-rod so that I can compare them.  Irvine parts are still available to some extent.

Rod.

As I don't know how to remove cylinder head and cylinder with no damage on this engine, I would prefer not to dissassemble it. Sorry.

Vincent

Don't be sorry. I completely understand. If you don't need to dismantle it, don't.

The cylinder head (known as the "Muff") just unscrews. It retains the cylinder which just slips into the crankcase. The original Mills had no way of preventing the cylinder from rotating if the Muff comes a little loose. It happened to me and that's why the con-rod is damaged. I'm pretty sure they rectified the fault on the Irvine by inserting a locator pin to prevent the cylinder from rotating.

I have a good collection of Mills engines.

The "Currie" Mills made in India by Aurora.
The one in "black" I purchased in 1991 and the "silver" one I purchased in 2005.
I have no less than six (at one time -- and have lots of parts) of the Aurora diesels.


The Russian made Mills 75
The P-75 Replica Mills ( not to be confused with the Doonside Mills)
I have four of these engines.


Then the Bodo Replica Mills from CS
I have eight of these engines.


Then the Irvine Mills
I have two of these that I purchased from Tower Hobbies in the late 1980's


And the Limited Edition Irvine Mills diesels --- the 0.75 and the 1.3


The Aurora made Mills were a hit and miss for quality, bad compression, poor fit, and rough finish.
The black paint tried to hide some of the poor looks of the engine.
It was one of those cheap engines you bought three of and mixed and match parts to get one good engine after some work.

The best (and hard to get now) are the Bodo Mills. Excellent fit, finish, and a strong runner!

By the way oldenginerod the conrod length from center of crank to center of piston wrist pin is .80" (20.33mm)
I've had to make a few over the years.
To make one, I use tempered 7/32" round bar stock, taper it a little towards the piston side.
Then file flat spots on both ends then drill the two holes for the piston wristpin and crankshaft at .80" on center.
New connecting rod in about an hour (or so).

I have used a 8x4 Cox Gray prop on my Mills 75 engines.
One thing I did notice is the serial number on your engine. Your's is  serial #2741
My engine has the serial #2724

Nice collection. Our Irvine engines seems to have quit the factory in the same batch ! Did yours went with a blue tank ?

Regards

Grosvince wrote:Nice collection. Our Irvine engines seems to have quit the factory in the same batch ! Did yours went with a blue tank ?

Regards

No,
I messed up the old tank when I was cleaning it (when I was younger).
I used some Glow fuel to clean the diesel fuel residual that was left in the tank.
The tank soften up because of the glow fuel. Maybe cause of the alcohol, or nitro, or both?

Found a replacement fuel tank on Ebay and purchased "two" of them. They fit better than the original tank did.
The replacement tank works just as good as the original. It's a light blue instead of a opaque "clear" colorl

You have the Mills .75 Mk1 version with a plain bearing crankshaft. A very limited number of Mk11 versions were made that had a single ball race by the crank web and plain bearing front. External distinguishing signs are the squared of exhaust port area, similar to the 1.3. The picture is of the one in my possession. If you see one for sale grab it as they are rare. Consequently, unless the seller doesn't know what he has, it will be expensive.
A good prop for the Mills .75 Mk 1 is a 7X5 (IIRC this was the preferred prop in the 'Tomboy' competitions).
HTH
PS. First post on here I think although I've been 'lurking' for years.

Well thanks DingBatSplat.  Glad you finaly decided to join the conversation.  
That's the first I'd heard about a ball-race version.

Oldenginerod wrote:Well thanks DingBatSplat.  Glad you finaly decided to join the conversation.  
That's the first I'd heard about a ball-race version.

My Limited Edition Mill engines have the ball race in them.
The ball race .73 have square top, similar to the 1.3 engines.
Also you can see the slight bump on the front of the crankcase

Hello.

Can somebody help me in identifying the following engine?
It was sold to me as a 'CS NAVO .375' - but it isn't! It is a .75 engine. somebody an idea?

Regards
Willi

Wow!, Love those engines, they look so cool!. I never realised when I was younger just how popular diesels were around the world. I new the odd person with one, but really amongst those I new it was mostly Cox, Enya, and OS glow engines, with some Taipan glow and diesels. but nearly all Glow. So I didnt really see all these different designs of Diesel engines. They are excellent! I love the Cylinder head and the rear fuel tank setup

Yabby

It's commonly known as a Boddo Mills .75 c.c., made by CS Shanghai for the late David Boddington.

I looked but could never find info on the single cyl. with screws down . Did find the twin inline , scroll to the bottom of the page >> https://www.adriansmodelaeroengines.com/catalog/main.php?cat_id=128

I was hoping you would chime in , If they made the twin in yellow head i would think at one time they made a singe cyl.? >>
What you think the worth of it is ?

I was good friends with David Owens and Dave Boddington until their deaths.
First met them when they came from Australia to the USA for a SAM Champs competition in the early 2000's.
Still keep in touch with the three other Aussies that came with Owens and Boddington (A. Laycock, B. Raatts, and Mick)
Two good guys that pass these worldly bonds.

True Boddington's engines were not anodized, while he was making them with CS.
Aurora had a class action suit against Dave and CS for making "Mills" engines.
Dave didn't have the money to pay Aurora to continue making the repro Mills,
so he cut a deal where he no longer would made repro Mills.

CS (ASP) on the other hand continued making Mills, O.S., and other "repro" engines (knock offs).
Because of the class action suit against CS(ASP), they stopped production of "repo" type engines.

CS changed the name of the "Mills" to Navo to steer around the law suit.

This information I received from Dave and was not widely publicized.
If you do a web search you may come across either the cease and desist website that was posted on CS's old website.
Or the history on the reason why Bodo and CS engines were no longer made.

So the engines with the "yellow" anodizing were done by CS and not with Boddington help.

Read this website for the information.
https://www.adriansmodelaeroengines.com/catalog/main.php?cat_id=128

Well I'm going to keep calling mine a Mills, because it's a Mills.  
No confusion here.  

Some of the Boddo engines towards the end had gold anodised cooling jackets. It is not incorrect to refer to the gold jacket engine shown as a "Boddo Mills"  if it was sold by David Boddington, or after his death, by his son Andrew Boddington. I bought one from Andrew from the last of David's stock after his passing.

Some were also sold by Steve Webb Models in the UK.

CS were never too particular about things like that.

The 1.5 twins (somewhat under developed and most having faults) were also sold by David Boddington as well CS directly.

CS had no connection with Sanye engines (sold as ASP, SC, Magnum, Kyosho and other brands). They are entirely separate concerns.

Here is a rare 1/2 size Mills .75 - the Aurora K-Mills .37. It runs very well after a new conrod in 7075-T6 was made for it. The original was too flimsy and made of poor material.

https://www.youtube.com/watch?v=1MqhzMZcwv4

Sad to read that David Owen passed away... I buy some stuff from here some years ago. Nice guy.

Grosvince wrote:Sad to read that David Owen passed away... Nice guy.

True. David was a true gentleman in my experience with him. He was determined to keep the engine building legacy of Gordon Burford alive with his Taipan 2.5 repro.
Australia has pretty much lost all of the "old school" model engine pioneers. I note last night that Adelaide Aeromotive, run by David Burke, has been delisted as a company. David (Burke) was trying to crack into the military drone engine market and as a sideline was reproducing and rebuilding Taipan diesels. He had much of the original tooling and some old stock parts from Taipan in Adelaide. Lets hope that he might pop back up as a cottage industry somewhere.

Here's a link to Ron Chernich's "Model Engine News" website.  
http://www.modelenginenews.org
Heaps of great information is fortunaterly still viewable on this dormant archived site.  Just reading through the last editorial again made me sad as Ron faced the inevitability of his impending passing.
Have a read and a ponder, learn lots of stuff.  Get inspired to buy a lathe and start making your own engines.

May I also recommend Adrian's site https://www.adriansmodelaeroengines.com/catalog/