Yes, perhaps becoming a little boring? But this is CHUK 3 MK 2.
The CHUK engine was designed to be built from Iron castings and of simple construction. A " Modular " approach was chosen so that different engines could be made using the same, fundamental parts. They were going to be cast in large volume in the Far East, but with my health having failed, quite drastically, the project was cancelled.
I'm not going to bore you with the machining aspects as they have been covered admirably well by Chipmaster, Jo and Twizseven in the various threads listed below.
http://www.modelenginemaker.com/index.php/topic,5124.0.htmlhttp://www.modelenginemaker.com/index.php/topic,9485.0.htmlhttp://www.modelenginemaker.com/index.php/topic,9743.0.htmlCHUK 3 was an horizontal design using a modified R.L.E. sub base with the addition of a single main bearing pedestal. The main bearing carrier was made as a separate part to help reduce the headaches of " in situ " line boring. A simple, right angled casting was done to secure the cylinder to the bed.
Otherwise CHUK 3 used the same set of castings for its construction as in the flywheel, crank, cam and cylinder head.
Work commenced on CHUK 3 before the year 2000 as the castings were from the Rhuddlan foundry. Being such a simple design the engine came together very quickly and test runs were conducted. This was when the disappointment set in!
I had continued with the " Stanley knife blade " shutter scheme across the now, vertically aligned flame port. This was, in effect its Achilles heel. The Gods had to be smiling, the winds favourable your tongue in the right place kind of engine. The video below was shot on a day when all the Runes were right! Needless to say CHUK 3 got shelved.
Having learned a few more tricks since then and the only engine built was sitting in the small power section at the Anson Engine museum, I decided to build another one from some leftovers. I was reminded of their origins by, strangely enough, the smell. Rhuddlan's Iron has a very distinct odour as its being machined, took me right back to my " hay days " of the business.
I decided to incorporate a " rotary valve " that I had used on A.L.F. see video.
This design would put the flame port underneath for better coverage. The, now famous " Chipmaster valve " was used in conjunction with my discovery of coil springs rather than flat ones used earlier. This meant a different cylinder head design was needed to carry the central 12 mm coil spring. The exhaust now exits by nine 5 mm holes drilled in a circle near the outside diameter.
I think the video tells you the rest of the story, CHUK 3 MK 2 actually works!!
Cheers Graham.