Mike Macartney

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About Mike Macartney

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  • Location:
    Norfolk, England

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  1. I did not realise, I have just found this on the internet: http://www4.briggsandstratton.com/miscpdfs/RNT/history of briggs_MS8751.pdf It seems they also took over the Smiths Motor Wheel company in 1991. They were used mainly on bicycles to motorise them. Thanks Chris, for the information.
  2. Here are some more photos of taking apart the bottom end of the V-twin engine. These bolts holding the locking plates for the nuts on the locking plate were not very tight. The locking plate was tight and needed some gentle persuasion to come away from the nut. It slid off eventually. I bagged up the parts and labelled them On other vintage motorcycle engines I have worked on, these big end journal nuts have always been extremely tight. Holding the flywheels is always a problem when trying to undo them I decided to try using the impact wrench first. The nut wasn't that tight, it spun off with ease. Cracking the taper is often a problem. I 'bounced' one flywheel on the wooden block and it all fell apart. All a lot easier than I thought. Hooray! This is a split pin stopping the main secondary conrod from turning. It will be interesting to see if it should have been a taper pin? There is a lot of slack in this conrod bearing. It looks as if there is another pin on this side.to stop it going in too far or maybe to stop it rotating. The big end shaft knocked out with a slight knock with the copper/hide mallet. I thought I was going to have to press it out. I am sure that is not a 'factory finish' to those rivets!
  3. I could then call it a Humberette Go-Cart and enter the Red Bull Soap Box Derby! Another alternative is to temporally fit a Briggs and Stratton lawnmower engine!
  4. Chris, Thank you for your thoughts. All ideas and thoughts are always worth consideration. I have started to get in a bit of a muddle as to who's messages I have replied to and who's I've not! Sorry to anyone I have missed out, thanks for all your posts.
  5. Al, I suppose the "Heat" is on, but if the trim is ready before the engine, it is no great shakes - I enjoy the problem solving - it keeps me out of mischief! Regarding the hood; a fellow Humberette owner in Australia thinks I am mad, having the hood made as the original, as it is very difficult to change lanes safely. Where we live there are hardly any roads with more than two lanes. One going one direction and the other going in the opposite direction. Nearly all the side roads are more or less single track. I cant see me going any great distance in the Humberette. Here is a photo of Kevin with his car in Australia. He has been a great help to me with advice and information on the Humberette's Kevin does lots of rallies with his Humberette.
  6. MIke, yes. The measurement from the top of the combustion chamber to the top of the piston on one of the two cylinders is nearly 4mm different. That is why I started my investigations to find the reason why. And then I started to find more problems! It now looks as if the trimming work will be finished before the engine is back together and running. Never mind, at least it keeps the brain cells working.
  7. Yes the pistons are the same height and are identical to each other. I am not impressed with the conrods, the big end bearing looks as if it has been machined off centre and the 'secondary rod 'pivot pin' looks rather small diameter. There is a lot of slack in this 'big end' of the secondary conrod. At the moment, I think I may see if I can find a 'fork and blade' rod that is a suitable length. Many V-twin engines at this period of time were 'clones' of J.A.P. V-twin engines, used in Morgan's and other cycle cars. I like the your great grandfathers patent drawing. Another project for you when you get bored - building his engine! It looks as if it would cause lot of wear on the slotted big end bearing surfaces. I can now see where your interest and expertise comes from. Can you imagine nowadays finding youngsters to hand crank your lathe for you? The Victorians and Edwardians engineers were a very inventive lot. I wonder how much more they would have managed to make if they had the materials that we have now?
  8. By way of a change from engine details here are a couple of photos of the hood, sent to me by Paul Moore the coach trimmer. He wrote "The hood is now stretched over the frame to allow the fabric to stretch" .
  9. In the UK pre war cars seem to fetch a very low price when compared to later classics. Below is a link to the H&H auction. https://issuu.com/paperrabbit2015/docs/h_h_duxford_june_19th_2019?e=32759311/70487414
  10. I am just wondering if Humber used this unusual set up to get over the problem of somebodies patent of two conrods working on the same big end journal? Mike, thanks for the link. By pasting it into Google I managed to open it. Very interesting. I still think that the first person who put this engine back together put the main and secondary conrods in the engine around the wrong way. I think I need to do a scale drawing or make a cardboard model to see if it makes the 4mm difference in compression height on one cylinder. Although the engine is proving a bit of a 'pain in the backside' I am quite enjoying the process of trying to sort the problems.
  11. Joe, I am sure if you had taken your working oil pump test rig to the local car show it would have created a lot more interest than some of the cars!
  12. Mike, I tried clicking on the link, but nothing happened! Also, I couldn't find a way to enlarge the drawing so I could read the text. The Daimler engine has a very narrow V configuration.
  13. Yes Joe, it is a weird setup. Here is a preview of when I split the flywheels. The bearings are bronze and not Babbit metal. More information and photos coming later.
  14. That makes two of us that don't know much about V-twin engines! I was having fun, until today, when I found what maybe a 'big problem'. I need to get my 'thinking cap' on to think of a way of overcoming it. I will post more about the problem later. Anyway, I am glad you are enjoying my investigations.
  15. The rod set up is unusual to say the least. You will have to wait and see what I mean latter on. I posted the last photo too soon and would like to show how I got there, for other Humberette owners who might delve into the internals of their engine, with the very limited information that is available. The inside of the crankcase on the LH side showing the steel repair plate that has been screwed on. This where the push rod for the valve comes out of the crankcase. This is the view from inside the crankcase. I will check the wear on them before I attempt to remove them. Removing them may prove difficult. This a view looking between the flywheels. The dents look like hammer marks on the big end to me? It looks to me if there is a separate big end bearing for the LH conrod on the RH big end? I would have thought the two inside faces of the two flywheels should be parallel? There is certainly a discrepancy in the first two measurements I took! This is the crankshaft end at the front of the car. This end does not seem to have any form of thrust washer? The shaft on this side is in very good condition. This is the gearbox end of the crankshaft that does have a steel thrust washer that should be against the phosphor bronze bearing in the rear crankcase. The shaft on this side has a little wear but nothing too excessive. While I had a chance I thought I would measure the distance from the flywheel face to the point where the thrust washer sat. Now it was time to get technical and attempt to mount the crankshaft assembly in the lathe, to try and find why the flywheels aren't parallel and by how much. The whole crank assembly is very heavy. How am I going to lift it to fit between centres in the lathe? A thicker bit of wood and a couple of wedges helped. Success, it was easier than I thought. I checked the out of trueness on each outside edge of the flywheel with a dial gauge. Marking the low point with a white chalk marker pen. At this point it is -0.015" low. The shafts were also checked and notes written in my book of the run out. With the crank between centres in the lathe it was now easier to measure more accurately the gap between the flywheels. I hope now I have enough information and measurements before I split the two flywheels to get to the big end. Presumably, the chisel marks are for lining up the two flywheels. A difference of nearly 50 thou between the widest and narrowest gaps. I would have expected that it should be a lot less. On the shaft on one end of the crank there was a run out of 2 thou and the other end 9 thou which I would have thought was too much. I was expecting 1 to 2 thou. I rotated the whole crank in the lathe to double check my measurements. (second lot of measurements are in the pink marker. The yellow marker is the gap between the flywheels.