2 little Indians

Hi Nigel only just found your reply .Yes heat usually shifts them but I have freed many of them with a soak in Acetone, ether or thinners. Overnight in a sealed container is usually enough

Any developments on any of the engines Klip. Hopefully you are feeling up to the task now . Regards John O/T

Mary returned safely from doing battle with traffic in Pretoria and Joburg but I have yet to ask about the Meehanite (know your customer!)

Glad Mary is safe home Klip. But don't catch your meaning about know your customer.

This little job has turned into a mission but a piece of Meehanite 240mm long has been collected by my dearly beloved.



Obviously sand cast as you can see by the little inclusions in the surface.



However, when you look at the cut end a very different view can be seen, there's none of the imperfections you often see in ordinary cast iron.



The large end is about 35mm diameter so rather than turn a large amount of precious material into shavings I've made 2 cuts across the top



and the cut the end off! I now have 4 pieces of roughly triangular material, 33mm long that can be easily turned into 13mm bar stock. Since the piston is only 8.5mm in diameter and 12.6mm long I should have more than enough material.
At this point a sincere thankyou goes to Brian Wiggill of BW Engineering, Boksburg, Johannesburg East who very kindly donated the material.

Klipkopwildlife wrote: This little job has turned into a mission but a piece of Meehanite 240mm long has been collected by my dearly beloved.

Obviously sand cast as you can see by the little inclusions in the surface.

However, when you look at the cut end a very different view can be seen, there's none of the imperfections you often see in ordinary cast iron.

The large end is about 35mm diameter so rather than turn a large amount of precious material into shavings I've made 2 cuts across the top

and the cut the end off! I now have 4 pieces of roughly triangular material, 33mm long that can be easily turned into 13mm bar stock. Since the piston is only 8.5mm in diameter and 12.6mm long I should have more than enough material.
At this point a sincere thankyou goes to Brian Wiggill of BW Engineering, Boksburg, Johannesburg East who very kindly donated the material.

Nice bit of stuff Klip. Wow though you've got enough to go into production LOL Very kind of Mr Wiggill to make the donation. Another modeller or just sympathetic to the cause ? Whichever a very valuable contribution. Nice to see you are fit enough to pick up the thread again. Regards John O/T

Brian and I have only corresponded by email, when he said 'no charge' I grabbed with both hands! [badass] At the moment I can stand for about 30 to 45 minutes so I am getting something done.

Klipkopwildlife wrote: Brian and I have only corresponded by email, when he said 'no charge' I grabbed with both hands! [badass] At the moment I can stand for about 30 to 45 minutes so I am getting something done.

He! He! I bet you did. Worth a few dollars that.You were lucky to find it .I couldn't see any here. I suppose there is some but I must have missed it./ B.T.W. Did you say you had steel for my crankshaft? Cheers John O/T
P.S. I wish I could stand that long

Somewhere I did say I have the EN30B for your crankshaft, even posted a pic!
Time to turn these lumps into bars.



And turn



Swop ends and turn again.



Turn to final size, lap with Wet&Dry to final size.

one tenor wrote: Hi Nigel only just found your reply .Yes heat usually shifts them but I have freed many of them with a soak in Acetone, ether or thinners. Overnight in a sealed container is usually enough

Just thought on Amyl Acetate does it too.

Yes I thought you had it but don't recall a pic. Not that that matters . Looking good for the pistons though .

At this point I found the bore of the liner is tapered, I should have expected it of course. In these sizes (8.5mm) a little means a lot. I was taking .04mm cuts and suddenly the liner slipped over the piston by about 3mm! So from there on it was lap and test.


You can see in this pic the marks where I've drawn lines with a marker pen and pushed the liner over the (soon to be) piston. You would normally do this with Engineers blue, but as per usual I can't find it!
The cut off tool is 2.05mm wide, so by touching the piston crown and adding 12.6mm I can cut the piston to the exact length.


Voila!

An exellent thread, and very interesting to see how much work goes into something so small.
An expert makes things look so easy.

The piston, now parted off.



Of course you now have a problem, how the blanketyblank do you hold it!


I've previously said the liner is quite tapered and the new piston is .015mm larger then the old one, so we use the liner to hold the piston, the taper locks the piston very effectively.


And we can now machine the inside of the piston.


My next problem was how to drill and ream the piston, not forgetting the cut out on the piston crown.

First take 2 blocks of steel.


Drill and ream 5mm and push in silver steel locators.


There are also 2 cap screws to lock the halves together.
Put it a 4 jaw chuck and bore for the piston.


The hole must be exactly on the joint between the blocks.


Piston locked in the block.