2 little Indians

1 of our members sent me 2 Indian Mills (.75) for checking and repair. Sent during the December rush they took a week to arrive in the country and then our Customs sat on them for a month! They had been sent 'to be signed for' so I wasn't worried about them. The value on the box had been put at 50quid so the Customs dutifully charged me 20% of that to get them out of hock!

The box was about 5 x larger than necessary!


The engine on the left which I've dubbed #1 has had a hard life and is the one with the damaged prop thrust. #2 on the right is the one that won't turn.

As you can see, some philistine has attacked the cylinder fins with a pair of pliers. What is immediately apparent is that they might be Indian Mills, but they are different. For a start the crankshaft threads are not the same. #1 thread measures 3.5mm and the nut being used is a 4mm nut. #2 measures 3.6mm and is a thread that I can't match on my thread gauge. I think it might be 4BA.
First the propeller thrust.


Buggered


and good, but the good one won't fit on the #1 crankshaft!

Could it be a hybrid ?

Has the damage been caused by the prop coming loose?, just wondered, boz

one tenor wrote: Could it be a hybrid ?

The difference is only .1mm, all I can think is the threading die was very worn when that motor (#1) was made.
I wouldn't have thought a loose prop would have caused that amount of damage Boz.

Hi Klip I know you can turn new shafts but what about the driver? That's a milling job isn't it? Btw not found any EN30 B yet What else do you suggest ? A couple of places have suggested machinable Nichrome steel. Would that be too hard?.I could try for an 8.8 bolt but it would need to be very thick to give a crankweb diameter at the head of about 1" ( not found caliper . I bet S.W.M.B.O. HAS MOVED IT. L.O.L )

Thought I'd just give you a heads up.
Before making stuff up parts are still available for the Indian Mills engines . P J Rose bought the stock of spares when the Indian factory finally gave up I think he is still UK agent for the company (?). He's not on the internet but I've called Pete on 07900 841550 with an order and he's put stuff in the post.

John, my experience is 30years out of date, it could be that nomenclature has changed. I would have thought that a Nichrome steel in a machinable state would be quite acceptable.
The original driver would have been stamped out of a steel sheet in a single operation. I am going to make one out of gauge plate, mill the centre hole in and use some kind of turn table to mill the driver face. I will then harden it.
Squirrel that's nice to know, Andrew Boddington also had some spares but very expensive. If I can't find a 3/32" reamer locally Rob (Box) may have to buy a new connecting rod.

The back plate on #1


And again.
As you can see the back plate has been attacked by someone without the proper tool! I used the head removal tool that you get with a Cox motor.
As you can see the prop driver is on the wrong way round but I think probably due to Box collecting the parts together to send to me.

I think the Amco .87 cc combination tool fits too. I always find someone has snapped off the tip of the C Spanner part. Don't know for the like of me know they do that. I'll put a spot of Stellite rod on it and grind it back once I'm on my feet again

#1 is now completely stripped




The connecting rod doesn't look so good but strangely enough it's straight!

I suspected something like that might be the case for the driver.A lot of work for such a small part

The Mills connecting rod always looks horrible to me. The big end bearing walls look horrendously thin.
My Mills had to have a new one made (courtesy of my Dad) after a number of years use. Now it needs a new main bearing bush but I have my doubts the old one can be driven out of the magnesium crankcase.

Being seriously under square, Bore 8.5mm x Stroke 11mm, plus a con rod length of 20mm, I would guess that most the loads in the rod are compression and to a lesser extent tension. Which of course is why you can make these rods out of just about anything. But I agree with you Q, any hint of hydraulic lock and it's goodbye rod!
What you would do with your Mills is clamp it nose first on a mandrill and skim off the rear to make it square. Then turn it around and clamp it in a 4 jaw chuck, turn out the bearing until it collapses, remove the chuck complete from the lathe. Make a new bearing in a 3 jaw chuck but under size to the crankshaft. Press the bearing into the crankcase, put the 4 jaw back into the lathe and ream the new bearing to the correct size. Phew!
A close study of the #1 crankcase nose shows some file marks which worries me.
#2 has been in thinners now for more than 2 weeks and I still can't get the cylinder out!