Opposed Piston Twin, D.Kelley

[fumopuc]

Dave and Art, thanks for watching, good to know you are still there.


The valves are the next parts to attack.
I do have a kind of standard process in the mean time, which is for me the best and easiest way to make them.
Hopefully the pictures giving a good overview.
The small radius cutter is turned by 45° and used as shear cutting tool to get a good surface on these SS (1.4305) valve shafts.
All these jobs were done last weekend.

[fumopuc]

And the next part of the valve story.
When I was just parting off the last of my five valves today, the lathe stopped suddenly.
Reason for that, the v belt was broken. Not surprising because due to noises which could be heard in the last months.
I didn´t take care about, because I have bought spare ones some time ago.
Unfortunately the dealer has sent me the wrong ones, but this I had to recognise today when I wanted to use it.
A good opportunity to try plan B, taking the Unimat toy lathe under the arm and I went into the garden.
First time I used the ER20 collet holder with the Unimat, working quit well if you cut only 0,1 to 0,2 mm.
Next to do, drilling the 1 mm holes for the pins.

[Roger B]

As Jo says you can't have to many lathes     

[fumopuc]

Hi Roger,
yes, Jo is right.
But in the meantime I have got a new v-belt for the big lathe and could go ahead with making further parts for the Opposed Twin.
We have had a very hot summer here in Munich, with daily temperatures over 35 °C, so it was not really  fun to be in my shop under roof, but some minor progress was achieved. The spring retainers were made next and also the cams with the help of the CNC mill......

[fumopuc]

... next to so, valve grinding.
I have made some research under the USB microscope and was surprised about what could be seen there by using my standard grinding process.
For the first valve I have used the diamant grinding paste as always. The valve to valve seat connection was fine confirmend by the usual vacuum test, but the surface was looking horrible, in my opinion.
Picture #4 is showing the valve after the lathe operation.
So I have tried another finer grinding paste, see picture #5 and the grinding result of a proper sealed valve in picture #6 and #7.
I think I have found a better process to seal valves now.....

 

[fumopuc]

....now it was time to cut the valves to length and to adjust the valve clearance.
Last weekend, I have made the exhaust and the inlet manifold.
Both are soft soldered with a 250°C tin solder...

[fumopuc]

... and here the last pictures of the exhaust pipe and start of the intake manifold, the reference bolt is M1,6 at the last picture....

[fumopuc]

... and here we are today.
Next to do, ignition.

[Vixen]

You have made a tremendous amount to progress Achim. Beautiful work as usual. It will not be long before we see a running engine

Mike

[Ye-Ole Steam Dude]

Looking really good.

Have a great day,
Thomas

[Admiral_dk]

Nice progress Achim 

I must admit that it isn't obvious to me how you adjust the valve clearance - do you move the cam shafts ever so slightly 

Best wishes

Per

[b.lindsey]

Just getting caught back up with your build Achim. Very nice work and a fine looking engine!!

Bill

[crueby]

Terrific work!


 

[Dave Otto]

Nice progress Achim, everything is looking great!
Beautiful work as always.


Dave

[zeeprogrammer]

I always enjoy watching your work Achim.