911hillclimber

Hope to do the same next week! Just bought another 'kit' off Hemmingway, the Atom Minor Mk3........

Oddly, made the brass ended pin in a jiffy and is a nice snug fit and feels good in the cylinder, so job done. Wonder if the ends will last?

It is the MT fuel now on order. Further delay until I try to start the Sparey.

After I get it running I will clean and paint ready for display! Just realised that I have not finished the wrist pin. I have to add the brass pads on each end, so that fiddly job to do while i await the cylinder nuts AND the 1/2 litre of diesel fuel off ebay. Local model shop cannot supply diesel or glow fuel now! £23 for the fuel!!

Today, I went to the local model shop to buy a tin of diesel fuel. No. None available to them and no glow fuel either as an aside. They cannot get stock. Thus a 1/2 litre tin off ebay for £23. Sobering.

Castings and finished engines look fab. Envious! will you make 2 more?

The engine mount plate is bolted through the work top, not using the camping at all. The work mate is a very flimsily affair, but allows starting in the garden so no fuel over everything in the garage. Thanks for the advice on the prop, and also the starting technique, I think that will save me a lot of frustration! As to the piston lightening machining, well, that looked impossible to me! Pesky gaskets cut (and fit) so total clean down tomorrow in brake cleaner spray. The bright 1/2 nuts on the cylinder bug me, so have ordered some blackened steel full nuts off ebay today. Worth the wait to use them and will add to the 'period look' on final assembly. I was going to engine paint the cylinder, but i think the fuel will lift anything but electro plating off, so not worth the effort. Thinking of the next project which I think will be getting my 2 old sparky engines to work. That can't be too hard surely??

It is a wooden 16 x 6 with a 8mm/5/16 crank shaft hole. Penn models' site say they have 12 and 14" x 6 but their stock is not always as per the web site. Oddly, they are 1/2 the price of ebay vendors. A lot concluded today. The Last Chapter is opening on this project. The Myford compound slide is back in it's box. Best £17 I spent on this lot. This means No More Milling. The cast iron scrap pile I hope/think is finished, this lot represents a lot of wasted time and a few bob on cast iron. The tube prop nut is made and holds the huge prop. Will try to get a smaller one from Penn Models when open on Tuesday, they have a 12 x 6 in plastic. £10 and 1/2 the price of the wood one. Will get 1/2 litre of fuel too. Did the final dry fit up on all the parts and thus just the fiddly gaskets to make, later this afternoon/tomorrow's task. Thoughts turned to running the thing. Found a nice piece of 10 mm alum plate, so cut that to suit the engine mounts and then 2 M6 bolts to attach to the work mate. I guess this will need tethering to the lawn (if it starts...) Made the wood starting 'aid' from a piece of dowl to keep my small fingers being chopped-off even smaller. Found an old engine stand I bought a very very long time ago , but it is so nice shame to butcher it for this thug of an engine. Little Enya engine is seized. So, what can possibly go wrong over the next days? I have little confidence it will run. I do not feel a lot of compression, and if it does run not sure if all the parts will tolerate the shock, let alone me. I want to get a picture of it running, clean it down of fuel and put it on a stand. Only then will I have proof that you can get by on a 1924 Drummond round bed lathe. 73T 911 Coup

A starting stick is a very good idea! Thanks as ever. Can't I simply cut the tips off the wood prop and re-balance?

The prop was bought to start it, not sure I can get my fingers out of the way fast enough! Ouch, or A&E ….

Fresh day. Loaded with all this good advice, thought I would sort ot this binding problem using these advice notes: Having slept on this problem and taking advice from Those Who Know on a model aero plane forum, set to to find why the engine is in bind. After 10 mins it was found, the problem that is, and the solution was easy enough. The cylinder mounting flange to the crank case was out by 10 thou, the cylinder was thus at an incline to the crankshaft. Solution was to place a razor blade under the rear half of the flange and nip the nut up and the engine rotated freely. The blade is 10 thou thick so I needed to machine the cylinder (very high risk option) or to reface (by hand) the crank case face by good old files. This was quite easy and I crept up on the change until all was good. So, the lot assembled and tight the crank/piston etc all are smooth. I've marked the front of the piston on the crown just in case this lot has to come apart after running in. Similarly the con rod as it can go onto the crank pin 2 ways. I'm pleased to say the exhaust ports are fully open when the piston is at BDC, I hope this is correct. After a good clean of the lathe of cast iron granuals and a good oiling of the bed, I took a look at mounting the crazy large diameter wood propeller. Decided to make a sleeve nut, tapped M6 to suit the crank shaft and 8mm dia to suit the hole in the prop. Not a sensible idea as this would leave very little wall thickness to the sleeve of the prop nut, so that nice piece of alum bar which was perfect is now scrap. A visit to ebay again for some bar, but also for some diesel fuel and start-up (or an attempt) is not far away. Need some gaskets first... 73T 911 Coup

Thank you Jon for the speedy reply.

Please forgive this intrusion gents: I am trying to build a 5cc diesel and I read a 15 x 6 prop is right for this vintage (low revving?) engine. This prop is HUGE to what I'm used to. What is the ideal prop size for a 5cc deisel?

Thanks as ever. You have more patience than me. I have nothing to loose, so will widen the rod swing slot in the piston. This may allow some float and allow the piston some freedom, or less binding. If I slacken the cylinder nuts off the cylinder the crank can be revolved much easier The prop arrived today too, it would fit a Tiger Moth….

Thanks for all the helpful details, but... Not a good day at the lathe today. Wasn't quite in the mood, but pressed on. Made a piston 'blank' that seemed a good fit in the cylinder, tight'ish at the TDc and slightly loose'ish at BDC. Drilled and reamed the wrist pin hole 3/16", no probs. Re-aligned the piston in the cross slide and started milling the inside of the blank to take the con rod. I happened to machine it 90 deg out, so no slot for con rod to articulate. Ok, turned the piston to allow correct slot position. Machined the 3/16" slot which sounded not quite right.... Removed the piston to find the cutter had gone throu the piston and was 1/16" off-set. Got my arithmetic wrong. God, I'm good at this stuff. Made another piston, all thou or so tighter (practice makes perfect), drilled holes, milled slots all in the right position. (practice makes perfect). Assembled the lot together and the movement is tight, cannot see any touching points of the con rod to the case to the cylinder etc so reversed the piston on the rod. Same condition, so something not square. I cannot see how to find and get rid of this high friction point, so seriously thinking of tarting the outside of this lump of metals, and put it on a stand. I finally think I'm a mechanic not a machinist. 73T 911 Co