pch_29

Sorry but it's mine now, did the dirty deed & collected it in person.

Not sure how NIB it actually was as there were signs of having been mounted and played with.

I had problems when initially trying to start it, though I cannot be sure whether these were down to my efforts or the previous owner, I don't really know.

I sent it to Andrew Boddington for checking & repairs and it is now back home & has run beautifully in the test stand with some fresh D1000 fuel and 9x4 prop, as reccommended.

It has a very unusual feel when flicking over due to the 2 compression peaks and the sound is something else, not as high pitched as I expected and very noticeable if 1 cylinder drops out.

It still needs plenty of running in as I have only run a few tanks through it and havn't had chance to check the revs, but for the moment has been put away with my other CS Boddo Mills ( I know have the complete set) till I move house and can get more time to play.



.....................Paul Harrison

fiery

My Feedback: (2)

Welcome to the club Paul!

Some still photographs or (even better) video footage of it running would be nice.

Are you sure you can't oblige?

fiery

My Feedback: (2)

A new offering from CS:

http://www.csmodelengine.com/?a=product&id=35

video:

http://www.youtube.com/watch?feature...&v=-NQ1OuKSn5U

flyingflea1

OK guys, what Mills is this from, all dimensions are metric apart from the venturi thread which is 1/4" x 40 tpi, nut is 11/32 AF.
Tank top is 20.5mm dia

thanks.

aeroland

Hello flying flea,

flyingflea1

Thanks Jon, that's a very comprehensive assesment,
rgds Sion.

fiery

My Feedback: (2)

The Mills .75 and some replica's.

Mills S.75 showing spring and cut-out arm.

earlwb

There is a business in the UK that is or was selling aftermarket fuel tanks and assemblies for engines. It is most likely one of those aftermarket items.
I had bought one last year myself too.

fiery

My Feedback: (2)

Here is a flat twin, apparently made using version 1 "Boddo Mills" .75 top ends.

As it warms up it begins to slow down and sound over-compressed.

http://www.youtube.com/watch?v=88EyRl_kU_0

ffkiwi

I see that clip was posted by Tom Crompton-he is reasonably well known for his engine restoration work-and has produced several Mills 75 based twins in the past-though the ones I have see have been in-line jobs, a la Taplin or the CS Oliver (more Taplin than CS in that they retained the sideport induction)......thought I had a photo in my files somewhere.....but I can't seem to lay hands on it at present .........

ChrisM
'ffkiwi'

fiery

My Feedback: (2)

An in-line 4 "Mills", also by Tom Crompton. Impressive piece of engineering.

http://www.youtube.com/watch?v=jnlWY1gUN6A

ffkiwi

Was it running on all four cylinders? Very hard to tell from that clip. The four layout is the same styling as his twins-the red crankcase seems to be his 'signature'

ChrisM
'ffkiwi'

Diesel Fan

You would think so as the front three pots were exactly the same compression setting (well looked like it anyway) and he only fiddled with the rear most one - so at a guess he had the front three already dialled in and the back pot, being a rogue, just needed a tweak.

ffkiwi

I'm not sure-I didn't hear an exhaust note that would convince me I was listening to four firing strokes per rev....or two double ones....

ChrisM
'ffkiwi'

Recycled Flyer

What would the crank throw setup be though?

2up and 2 down? If that's the case then all you are going to hear is a twin cylinder anyway.

ffkiwi

Well it can't work firing sequentially can it (not as a sideport two stroke)-so we are left with either simultaneous firing or alternate firing -and two possible variations for the latter-front two followed by rear two or 1+3 followed by 2+4. If someone has an audio tach they could use it on the You tube video-the revs didn't sound that high-suggesting simultaneous firing to me. I suppose with an in-line setup like that-and the likely crankshaft structure it might be possible to incorporate better counterbalancing than in a single cylinder Mills so vibration of a simultaneous firing setup might not be that bad?

ChrisM
'ffkiwi'

James walker

Hi all
I am need of help please
My Dad has a Irvine mills 0.75 mk II and he wants to relive his youth.
The engine is missing a piston and contra piston, also washers for the prop.
What I can find out the liner will need to replaced all in one go, but I cannot find any pistons contra piston and liner for sale!
Does anyone know where he can purchase the piston and liner parts and any advice to change the liner?
All information will be helpful

Thanks

James

ffkiwi

At this stage-not a hope! These engines have been out of production for about a decade-and the supply of spares is virtually consumed by now. There are a few carbs tanks etc still popping up on Ebay, but not much else-and in your particular example, there were not many of the Mk2 75s made.

I see several solutions-one would be to fit an Indian Mills 75 piston and liner assembly (lesser quality but probably easier to find)-the Indian ones too are out of production-but more recently-so spares are still about. The second option-and it WILL be expensive-is to get one of the engine restorers/rebuilders in the UK to make you a new piston and contra, using the original liner. There are several individuals who do this sort of work-Mike Crisp being one-but their highly skilled services don't come cheap. I suggest you raise the issue on the UK SAM website-they will undoubtedly be able to provide you with details.

Alternatively, you could (i) keep an eye on Ebay and pick up a second hand Irvine Mills 75 Mk1 (the Mk2 models come up only very rarely) which come up reasonably frequently, or (ii) buy a new or second hand MP Jet Classic 0.6cc engine-which is very similar in physical size, handling and performance to a Mills 75.

What is the more important for your father-to actually use his original engine again? Or to indulge in the same style of flying he used to do with it? The solutions I've provided will cover either of these........

ChrisM
'ffkiwi'

PS I'm not sure from your post whether you have quite grasped the subtleties-diesel spares are always sold as complete piston liner sets-you cannot purchase a piston or a contra separately-these parts have to be lapped or honed to an individual cylinder-and the fits required for each are both critical-and different-that of the contra being critical to the order of 1/10000 of an inch.

PWF63

Surely there is someone on this forum that could make James a Piston/contrapiston for the Mk1 Irvine Mills.

aeroland

Hello James,

There is currently a drive washer for the Irvine Mills .75 listed on eBay. See item no. 171014495523. ( cut from here and paste in the eBay search field). Looks like a mk I part and do not know if if fits the Mk II. As far as I know the Irvine Mills .75 Mk II is identical to the Mk I with differently machined crankcase to make it look like a Mills 1.3 Mk II. As Chris has pointed out Mike Crisp and others in the UK can make the missing piston and contra piston for you. I assume gudgeon pin is missing too.

I can also make the parts for you here in Australia if you wish, including the gudgeon pin if required. Would need the engine here for test running purposes and adjusting fits. Regards - Jon Fletcher. (jonfletcher'at'optusnet'dot'com'dot'au)

flyingflea1

Hi James,

Ripmax list some Irvine Mills parts,

see here,

http://www2.ripmax.net/Category_List...Category=X0600

good luck

Sion.

balsaworks

The Attachport 1.3 - a British replica of the Mk1, Series 1.
Don't know much about this engine but it is very nicely made.
Incredibly clean and functional design - a real beauty.

James walker

Hi all

ffkiwi

What exactly do you want from us? If this is the same Mills you mentioned in your previous post, then it is NOT an Irvine but an original Mill Bros manufactured one-made sometime in the period 1949-1964 if it is a normal Mills 75 Mk2. The serial numbers you describe confirm this with 100% certainty. If it has a cutout device (rotating airbleed collar) fitted to the carburettor it is the S.75 model, if it doesn't it is a P75 model. And the bad news-none of the Irvine Mills 75 parts will fit it-apart from the complete carb assembly (ie venturi, venturi nut, tank top, tank, needle valve and spring and jet assembly) fitted as a unit.

If you're still after bits, then the only option is to use parts from the Indian manufactured Mills 75s, as these were produced using the original Mills Bros tooling and jigs. Again the Indian ones are now gone-so their spares situation is dwindling. You can of course buy a complete engine (original or Indian) and cannibilise it-or get the parts made by one of the UK specialists who do this sort of work.

ChrisM
'ffkiwi'

aeroland

Hello James,

I confirm Chris M's comments about you having a genuine Mills .75. I can supply some spares from stock for the Mills .75 and 1.3 engines. Others I make to Customer order. All as exact replicas of the original parts. Most of the parts I see made in the UK appear functional, but are not exact replicas. In some cases I use superior materials than the original or use my 45 + years of design engineering experience to apply some engineering improvements, with the awareness of my Customers. Can also do rebores and all levels of refurbishment.

Regards,

[email protected]