McDonald Imperial Super-Diesel

The cut away engine is not mine but the video is. Only difference is that mine has an extra coffee pot hopper on top of the water hopper to hold extra water. The video does spur me on especially with cobwebs and smoke out the exhaust. I got a glimpse of the oil primer being pumped but didn't seem to do much as it is designed to force oil down the tube to the piston rings and gudgeon pin and his pumping appeared to be doing nothing. I have found the outer section of the primer which is a round cylinder but is bent like me. Not sure if I can straighten it and try to design and build the rest of the missing parts once I know what is inside. Again a challenge for down the track.

You've got to love the cobwebs and the crap piled up on, in, and under the shelves - just like many of our garages no doubt?

PDU wrote: You've got to love the cobwebs and the crap piled up on, in, and under the shelves - just like many of our garages no doubt?

Cleaner than mine but I am working on cleaning it up.

I was surprised how easy it started...then I see a spray can in the junk .......that used to be a good trick in the used tractor sales yard .....spray in the aircleaner befor the customer turns up ...tractor starts up straight away for the first and last time.

With some of the old cars I've bought from car yards over the years I always wanted to see them start without the ever present booster battery to help them. :huh:

1st up today was to drain the hopper of the molasses mix. It held a good head considering it has been in there about a week. Once drained and rinsed it was not too bad, still some flakey rust but good enough for a "Weekend Warrior". I started to measure up the width of the ring glands. I was told that they are 1/4" but these ones are only 3/16" wide. The top ring gland measured in at 1/64" wider due to a bit of wear but it will remain the same. Even though I have a set of digital calipers they measure imperial to the decimal point and that is too hard for my head so I used my good almost unused drill bits and they are a quick reference point.

Then it was time to play with the bore. It had a lovely layer of crap top to bottom and wiping it out alone did not even look like removing it so out came my small El-cheapo, spring loaded honer. Just connect to the drill and add some diesel and away we went. You can see the sludge that it was removing, no wonder I thought I saw a mud crab early in the rebuild. Once cleaned up enough that it was smooth at least I decided to trial fit the rings that were on the piston that was not in the engine when I got it and I now know why. Remember the stack of rings I made with the ends almost in alignment and there were 2 that were longer? Well as it turns out the short ones have a gap of 0.060" and the long ones overlap by at least 0.100". Going by a quick Google search it suggests 0.004" / 1" diameter of the piston. Piston measures the 3.5" exactly as it should with STD on the top so that equates to 0.014" ring gap. So with a bit of work I can get 2 of them down to size but I found a bloke in Wyee NSW who I spoke to today and he can supply the correct rings once the factory goes back to work and he brings them in from N.Z.

To finish the day off I had a respectable bore but then looked at the sump drain to see what I need to plug that hole. When I first looked the hole was smooth which could not be right so with a wash and a good light I noticed the pipe had been broken off flush so out with a hacksaw blade and cut the pipe and use my new trusty home made slotting chisel to collapse the sides in and knock out the thread.

cobbadog wrote: I got a glimpse of the oil primer being pumped but didn't seem to do much as it is designed to force oil down the tube to the piston rings and gudgeon pin and his pumping appeared to be doing nothing. I have found the outer section of the primer which is a round cylinder but is bent like me. Not sure if I can straighten it and try to design and build the rest of the missing parts once I know what is inside. Again a challenge for down the track.

See my reply on Smokstak. I may have what you need.

Jarrod.

On old motor bikes ,the oil plungers were pushed down ,and came up slowly under spring pressure,feeding oil thru a drip sight glass......i think all a stationary motor needs would be a small oil tank and a needle valve to regulate the flow .,.....no pumps needed......Incidentally ,be interesting to hear how a ring too big for the cylinder bore managed to fit the piston,and work.......little bit of wear somewhere.