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Wanted: McDonald ML

Darryl

Registered
Thank you fellas. I’d previously bought that engine when it was advertised as an ML and paid a fair bit too. I used up a big favour with a mate and his truck to pick it up, 4 hours away. Voutier ( the vendor) wasn’t there as arranged so we found the engine and it was an M which is OK but when the dickhead finally got there ,he was already angry about something and wouldn’t re-negotiate at all, and said he’d scrap it and took off in his car flat out. We drove home empty.
so yeah, that one is unfortunately not going to be mine.
 

cobbadog

Registered
Some people make you wonder don't they. As my late father in-law used to say;
"You can get a grunt out of a pig any time you kick it in the guts"
 

asw20

Registered
Purely out of curiosity, what's the difference between the two models? Something quite substantial, I assume...

Jarrod.
 

Darryl

Registered
The only difference I know of is the piston crown shape and internal shape of the head was re designed on the later ML to produce an extra 20 hp. An expansion chamber exhaust was also added. ( ML is an M with Loop scavenge)
 

Wayne Timms

Subscriber
Last Subscription Date
06/09/2020
Hi Guys,
I also took an interest in this engine. At around the 6k mark I thought the price wasn't bad if it had been an ML, but without the oval exhaust flange I thought the engine was an M and didn't bid. Its probably rarer than the ML.
Wayne
 

isandian

Registered
Darryl is spot on with the difference between the M and ML, but I might add that they are identical in bore and stroke. Loop scavenge was applied to a couple of McDonald 2-strokes after the war, but the increase in power of the ML was extraordinary compared to the TL over the T.
Incidentally, mention of an oval exhaust flange reminds me there were variations in the ML. Mine (and most others) have a circular exhaust port, coupled to a circular profile cast iron expansion chamber. I have seen a couple of examples with a larger oval exhaust port with a correspondingly oval profiled expansion chamber (it is huge!). I have never seen any documentation on this, but one can imagine this provided an even greater increase in power. One example was at the Bordertown SA engine club site many years ago.
Ian
 
its probably not going to matter unless your planning on running it to utilise the hp it has or not, ie put it on a real sawmill.
All the videos posted are running free of load to light load with small pump.
So what's the it going to matter, sure price reflects hp usually in modern engines but its old and on show so cannot really compare.
 

Darryl

Registered
You are right Alastair , I would love to have the M but wanted an ML specifically and would have given a fair
price also but there simply wasn’t any hope of a half civilised conversation at the pick up location.
By the way, I want the ML to drive a 15” Robison pump so it will be working alright, if I ever get one.
 

Wayne Timms

Subscriber
Last Subscription Date
06/09/2020
Thanks for the information Ian.
I've only ever studied 3 MLs closely, and all have the oval port. I noticed the Ms had a round port, so that was my way of determining the difference. Clearly I was wrong.
Wayne
 

Darryl

Registered
Well, i ended up buying the M at the last minute on Sunday. We had a camp oven with some family and friends when I was suddenly struck with sense of loss so I snuck to the house, looked up the auction and it only had three lots before the M so I put in a pretty low bid and walked away. My good mate turned up later and grinned and said “we’re going back to Camperdown again I see“. I nearly spilled my beer. It’s a nice engine to have but I will still hopefully get an ML one day. I’ll need to live a hundred more years to pay back the favours I owe Rob, my mate who never fails to help. Thank you to all you guys who helped also.

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cobbadog

Registered
What a whopper ! Glad you bought it at a price that you are happy to own it. One day we will hear it ticking over and trembling the ground, can't wait and well done. Sounds like your mate is a true mate too.
 

freshieslures

Registered
Hi Darryl, sound like it was worth the wait to get it at a better price, I had a go at the jelbart engine a few lots after it but didn't really come close. Look forward to a video of the Big Mac running.
Cheers justin
 
see if the pump performance data is available for your pump, it will be a graph with a curve. thats if they are still around.

then you can see if you can make the pump you have work with the engine you will soon have.
you may need to change pulley ratio to suit.
 

isandian

Registered
Congratulations Darryl! Good buy, and it looks exceptionally complete. I hope the main bearings are OK, as Kevin will tell you the M he has was not in the best of condition. I am sure you have been following his work on it on facebook - he just got it going last weekend but is missing a few important bits.
 

Darryl

Registered
Got the big bugger home. Very complete , the clutch has been welded up but i can neaten that up . The main problem off the bat is the hot bowl is missing !
I didn't check the first time i looked at it but i still would have bought it.
Anyone got a spare hot bowl ?
Screenshot_20200619-143822_Gallery.jpg20200619_161535.jpg20200619_172120.jpg
Dragged it from my mates place to my place in the tandem with my old ute. HEAVY !
 
ask to copy one, get them to either machine one from solid or cast then machine what's required.....
Make sure you fit the correct part for that engine and it has right volume requirement so your compression ratio is correct and it does not hit the piston.
Not sure of design so just saying check a few things.

i suppose you can ask for one see how you go.

If the clutch is a bit so so i am sure that could be fixed as well, at least it is there.

If it was stuck in the bush they probably did what ever to get it running with what they had. not doing a proper repair.
 
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isandian

Registered
Alastair, the hot bowl is well clear of the piston, and its volume is not too critical as the compression ratio is only about 5:1.
Darryl, I may have a good hot bowl, but you will need the hot bowl clamp, too. i am pretty sure they are the same as on your TL engine. It's not too hard to make a basic clamp, since you do not need the wind shield for your purposes.
I will check tomorrow.
Ian
 

Darryl

Registered
Thanks Alistair, I do have the required part off a smaller engine to copy as they are the same size if it comes to that.
Ian, the clamp is there which is lucky. If you did have a spare hot bowl, I’d happily buy it but I’d hate to take a spare and then you needed it down the track , knowing your a McDonald man also.
For interest sake, I found the engine came from the Bookam auction ( spelling?) and was a saw mill plant.
 

cobbadog

Registered
What a sight that must have been in your inside rear view mirror! An what a grin it must give you as well when you look at it. Look forward to any and all progress and already it sounds positive.
 

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