McDonald Imperial Super-Diesel

I can always come up with a stupid new use for tools and thought this will be different just like me. Low and behold it worked a treat and the new rings will be fitted the same way.
Yes, I arranged them that way to show the wear and have no idea as to why. I do know that they never had an oil ring on the bottom ring gland and I will attempt to track some new rings down from a bloke over at Gloucester NSW.
I also want to clean up the bore from all the dirt and crap in there and slip the rings in at the bottom of the bore as described in the "Instruction Booklet" and check the ring gaps, I bet I get some shocks when I do this. The piston is as close to being the 3 1/2" OD so that is good and the ring glands are not showing any signs of wear and the shoulders are perfectly square so hopefully a set of standard size rings by 3/16" in height will do the trick.
Apart from the cam gear I don't see much wear and tear in here but then I haven't looked too closely at the head yet.

Generally caused by wear...probably wernt to fussy about the aircleaner when the motor got older......dont think oil use would worry them when they were using sump oil everywhere.

Yeah, there is no sign of an air cleaner only the body that it bolts to. I have a plan to make one when its time.

At least in car and bike engines I have always found the top ring wears the most.

Jarrod.

I notice the hole in the piston that lets oil drip down onto the smallend bearing....also notice the pin seems to be touching the cylinder bore ,not good...Otherwise seems to be in good nick .....I d just swap the rings round ,best ones on top to seal compression.Even 3/8 ring gaps you can live with if theres enough rings......Old trick is 1/2 width car rings ,two per groove ,gap is sealed .....incidentally ,3- 1/2 is the WW2 Chev truck bore ,old Chev rings may work.

Yes the hole is for oil to be forced down to the gudgeon pin by using the oil primer that is missing at the moment and is what that brass oil tube if for inside the hopper. Start up procedure is to decompress the engine, fill the oil primer and pump away while rolling the engine backwards to lube the rings, bore and pin.
A company known as Bills Motor Parts at Wyee NSW has a huge selection of rings and valves and I don't know what else so I will see if he has some new ones, if so they can be sent up.
I did read about using multiple rings in the one ring gland so thanks for that.

Off topic and I can't remember who was asking about a picture of our Clubs Tangye engine showing the bearing. After searching hi and low and no help from members this is the only pic I have.

That was me. Thanks for your efforts. I have now worked out how to make them. May not be quite original, but will work.

Cheers.

No eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configurationCobbadog

Is this your motor? Cutaway model belonging to Victorian Museum.





This also might be handy


And to keep you enthused.


And something for your shed

Hello Jarrod,
Butting in on cobbadog's thread.
My engine was missing the big end block and crankshaft bearings. For the mains, bronze bushes I had were made to fit the crankshaft plus a bit more to fit the housing.
The big end block was made to take a piece of new brass pump barrel.
David.