911hillclimber

This will make a nice paperweight! It will NOT start no matter what I do or try. Do not feel inclined to keep on trying as I feel there simply is not enough compression to get to the ideal mixture. In the meantime I've bought another design to make on the Drummond. It is a 1933 design spark ignition, 6.3cc and more complex to machine. Tinkering is better than using. The audience has all but dissipated now, so thanks for following the adventure, and a special thanks to those who have guided my progress on my first engine. I won't do a thread on the next engine. 73T 911 Cou

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

Thank you Keith. The prop is in the post to give me a bit of incentive! Any thoughts on the fit of the contra piston?

The fine 1200 grit powder arrived 2 days early, so mixed some with a drop of engine oil and set to polishing the bore some more. I really doubt i can improve it further, so have called that a day, and started turning the cast iron piston. I'm experimenting of getting a good chatter-free cut as I reduce the bar, and may have found the happy spot of cut, feed, tool overhang and angle. Quite a few variables but will try some refinement tomorrow starting with a fresh tip. Plan is to make a new 'tight' fit piston by lunch tomorrow.

Great we all have a choice! This conversation is a direct parallel to the car industry, some will take EV and not. I'm sure the supply (as opposed to cost) of suitable fuels will govern what happens. If fuel stops then switch to electric and keep flying, enjoying all aspects of this hobby and all is well. IC vehicles will slowly die out, 20 years? The fuel for both will become the issue if/when electric becomes the best seller, the fuel will be the issue before the vehicles are worn out I suspect. Mind you, supply of electricity will also dominate the world too! We will all revert to rubber free flight....(just joking)

Just my take on this subject. I last flew/used IC when in short trousers almost and I cycled everywhere. I was 12, so about 1964. In 2020 I had retired early and fancied a return to model flight for some weekday action, preferably with vintage planes, ie Ben Buckle. However, what was all this RC malarky? I needed a trainer, so bought a foam Kingfisher with electric and all the gubbins needed and joined the local club. IC there is restricted to say the least, so electric was ideal, fly any day that allowed it weather-wise. Preparation very simple, charge the night before, go and learn to fly (not quite there yet). My 'buddy'/trainer flies a 4 stroke and it is really nice, love the sound, lover the performance (heavy plane cuts the air). However, cannot see me doing an IC ever, electric is just so convenient, bit lazy maybe, but I feel the right thing for me to restart the hobby. Is electric the future, I think it is, BUT, if you try a little, IC can be the way for ages. Fuel and noise will determine the way it travels, or rather glides, to the ground. I'll be long gone, but have memories of my new found hobby as electric, and a distant memory of my ENYA glow in my control line.

Dark grey, but imperfections in the bore. The bore was fine turned, don't have the right reamer, so tried to work the surface with a new boring tip etc. I have to wait for the 1200 powder to come a few miles from me, it is in Birmingham.

Lapped the cylinder using fine cutting compound I've used on car/bike valve seats, and what a difference that made! Changed the look of the surface, but removed a lot of the imperfections. Have ordered the 1200 powder for £6 off ebay. Thought I would try 'expanding' the piston by heating to cherry red and quench. Did that twice. The previously slack piston would now only enter the cylinder 1/2 way, so the growth was far greater than I expected. Started to mess about with the lower part of the piston as it was the tightest only to find 2 hair line cracks in the 'skirt', so now scrap. Further wait for the 1200 powder to arrive and then can progress I hope.

Thank you both. Birthday today is 'my day' so have to fix the brakes on my car trailer, the season is soon to start, then to focus on the lapping. Being old I have the double ended paste from various engine valve jobs done over the many years, so may go back and start again there. Between the fingers 40 feels like 1! I do have some fresh alum plate which is mirror smooth so can see how 40 scrubs the surface compared to 1. I can borrow a small US cleaner I've used for motorcycle carbs in the past to clean the cylinder after polishing, but like the idea of the 1200 powder and engine oil as the final pass. All part of this project!

Ok, I'll persevere! Is '1' coarse and 40 fine or the other way round for the lapping grease?

That was my stance too. Oddly I have a new PAW from the 80s so will have a peek. Maybe a new tight piston tomorrow on the agenda.