IHC Titan 50 HP, 2 cylinder Doug Kelley, European version

[fumopuc]

Some rapid progress 

Internal O ring grooves are somewhat tricky 

Roger, yes. That was nearly a complete day working on it.

[fumopuc]

I had to increase the feed at bit and also to repeat the last turning around two times, to get a fine usable M2 tread.   

Sorry, I mixed it up a bit with my current job.
The here described thread is M3 and the shaft diameter is 0,97 mm in this case.
For my feeling not a big different, also here close to a heart stop when diving into the hole first time.

[Kim]

Wow!  That's a lot of top-notch work, Achim!  You've made a lot of progress on this engine and it's looking great! 

Kim

[Admiral_dk]

Great description - fine parts as a result  and I do understand the trepidation when using a Mill-Bit with such small dimentions ....

So now it's only the Heads that are missing or ....                     

Per

[fumopuc]

Kim,Per thank you very much.


Happy that I have got the O-ring issue sorted, I thought a good time now to do the coating of the cylinder unit and the liners, followed by a hopefully final assembly.


And than full attack to the cylinder heads, as Per already mentioned.
The recommended design from Doug was do fabrication work here also, specially for the in and outlet flanges too.
It was clear that the water jacket needs a fabrication work, but in my eyes the flanges are a job for the CNC mill too.
So I made a strategy and created the CAM for it.
The attached pictures do hopefully explain a bit the route how to get there.

[fumopuc]

A lot of swarf, but at the end we have got it, specially the outer shape.
In my first set up it was important for me to do the water jacket milling and hole pattern in one set up.
Unfortunately are there another two holes for the coolant passage, only half way through the head from the other side, the fire face.
So a simple fixture was made to get the heads in the right position for this drilling operation.
The hole drilling was a computer job again now, due to the relationship to center of the fixture, it was clear to him what do for each head.
Next challenge, the rest of the coolant passage, shown at the two CAD screenshots.
The CAD has given me the right angle to clamp the heads for this operation.

[Vixen]

Hello Achim,

I am sitting back quietly watching your progress and admiring your workmanship, it looks very good.   

The great thing about how we build our model engines is the wide verity of challenges we face and the need to find cleaver ways to create them. After weeks of fabricating cylinders and glueing O rings you now change to CNC machining the cylinder heads. Plenty of challenges, plenty of innovative solutions leading to the biggest prize: plenty of satisfaction.

Cheers   

Mike

[fumopuc]

And with the help of an old fixture plate, two new holes at the right place and some pins, I have been ready to do this final coolant passage drilling.
Last picture doe show the Plugs already, which will silver brazed to close the water jacket.

[fumopuc]

And here the heads in the actual conditions so far, with a slightly flat machining after brazing.
All this happened beginning of September already and by looking at the results in sunny weather I realized there are some things missing to do a final assembly.


Main point, I have some con rods but no piston.
So next to do, some pistons.
Target was to get 3 pieces.
All the necessary equipment on the bench and all available machines involved.
The lathe for turning operation.
The CNC mill for milling the con rod pocket.
The conventional mill for the piston pin bore.
The bar was clamped by a collet block after the lathe and than carried to the other machines for clamping in a defined position.

[RReid]

Still happily, if quietly, following along with your progress, Achim. Lovely work! 

[fumopuc]

As always I haven been curious how it looks like.
Next picture the prey, 3 usable pistons.
And the question, how to get them in easily.
Also here, as always I have made a tool for it.
The drill bit in first picture for a sample assembly, but not really useful for final a assembly.
So the piston pins had to be attacked next.
First piston and con rod at its new home and as always some trouble coming up.
Anywhere is the point, where a model builder has to recognize that mostly he himself is the reason for some trouble.

[fumopuc]

Hello Achim,

I am sitting back quietly watching your progress and admiring your workmanship, it looks very good.   

The great thing about how we build our model engines is the wide verity of challenges we face and the need to find cleaver ways to create them. After weeks of fabricating cylinders and glueing O rings you now change to CNC machining the cylinder heads. Plenty of challenges, plenty of innovative solutions leading to the biggest prize: plenty of satisfaction.

Cheers   

Mike

Hi Mike, thank you very much for watching and the friendly comment.
To be honest, I do like these different challenges very much.


Hopefully tonight I will find the time to catch up with your build report. 

[fumopuc]

Still happily, if quietly, following along with your progress, Achim. Lovely work! 

Hi Ron, thank you very much. Good to know that you like it.

[Roger B]

  

I had to look back to the beginning to see how the valve guides/cages would be fitted into the head. A complicated fabrication 

[fumopuc]

Hi Roger, thanks.
The design is very similar to the Bruce Macbeth Engine head design.
Main difference, the water jacket plug is here now not a the fire face side.
The valve cages, pressed in with Loctite, will be the same.
As another difference, Doug has used here bronze for the valve cages instead of steel at the BME.
I will do the same. The expansion coefficient may be does match better.


But, first there was another issue to clarify.
Turning the crank shaft first time with the conrods and pistons connected does create sometimes a little strange noise.
First I have been perplexed and could not imagine what the reason was.
After a more intensive examination, I have found a very little collision between my extended cam lobes and the conrods.
The lobes are not finally adjusted and the position, also axial, are currently more or less by random fitted.
So I had to have a look at the CAD first, because here the cam lobes are axial in its right optimal position to the center of the roller tappet.
And surprise, the CAD has known about it, but me not.
To solve the problem was not a big issue, but I had to disassemble it again.
The pictures below does show the slight modification at the conrods.
After a reassembly I have been ready for the drag test bench.
<a href="https://www.youtube.com/watch?v=YKwtrPsSKKU" target="_blank">http://www.youtube.com/watch?v=YKwtrPsSKKU</a>
The strange noise is created by the lead screw gear train of the lathe, not by the engine.