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McDonald Imperial Super-Diesel Engine

cobbadog

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YEs Dobbo, I did ask him but he was not at the workshop at the time and was going to get back to me about it. If I get time and remember I will give him a call tomorrow about them.
 

cobbadog

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Cleaned up the outside of a paint thinners tin to use as the fuel tank. I think it is about 1 litre bigger than standard so it is a long range fuel cell now. I have strengthened the bottom where the tap will go in and made up the mounting brackets to the hopper.20200527_141049.jpg
 

cobbadog

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It is where the original tank fitted. Only had a small piece of the original mounting bracket so I sort of copied it. Looking at it now I think it may had been better if it was the next gauge heavier even though there is no movement at the moment. Time will tell. I'm not sure but I think that maybe the original size of the tank may have been 1 gallon so this being 5 litres is a long range tank.
 

Darryl

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There’s been times where the compression has accidentally blasted back through the fuel line and blew fuel out of the lid which just sits on top usually. Your going to have a nice sphere if that happens with the lid on your tank Cobba.
It only happens when I prime the fuel by hand while cranking the engine or once when I was tightening the little gland on the fuel needle when it was running,but went too tight and it grabbed the needle , that blew the lid right off. You would be OK though if your smarter than I was !
 

cobbadog

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Cam gear is home and I started to linish it to shape. I believe these can be a fun engine to get set up and one thing that stuck in my pea brain was ensuring that the needle does seat well in the injector to ensure a good fit.20200529_144831.jpg
 

Scotty 2

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There’s been times where the compression has accidentally blasted back through the fuel line and blew fuel out of the lid which just sits on top usually. Your going to have a nice sphere if that happens with the lid on your tank Cobba.
It only happens when I prime the fuel by hand while cranking the engine or once when I was tightening the little gland on the fuel needle when it was running,but went too tight and it grabbed the needle , that blew the lid right off. You would be OK though if your smarter than I was !
Is that why they went from a cap to a lid? Our CC has a screw on cap and each end of the tank is bowed out. I thought it was made that way

 

cobbadog

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Interesting colour name associated with a Qld footy team. Maybe they knew something from way back then when they named it?
 

cobbadog

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Nice one Scotty. Once the Pumpkins are picked will they follow you home?
Oddly enough, looking at the oiler on that Mac it appears to be a normal drip oiler and not the usual oil primer. I have seen this done on a couple Macs and even an SE.
 

cobbadog

Registered
The next bit of dribble for today after work gave me just enough time to linish the cam profile but I found a couple of spots that need to be built up higher. The guy who welded this must have known as he mentioned that if I needed any part built up just bring it back, so it will go back to him next week.
Then I fitted both Speedi-Sleeves to the crankshaft. This took all of 5 minutes. I picked up a piece of exhaust pipe that was the correct ID to fit over the sleeve and a couple of light taps to get both sleeves into the correct position.
Not much play time today but at least something got done.
20200530_111528.jpg20200530_112425.jpg20200530_113237.jpg20200530_131221.jpg
 

Scotty 2

Registered
Okay.. Let's rephrase it.
Are those Queensland Blue pumpkins you're (trying) growing amongst the engines???
Mate, The pictures are from a few years ago. I wasn't growing the pumpkins. The lady where the engines were was growing the pumpkins before I found those engines and I was not allowed to take the engines away from her place until she picked the pumpkins. I don't know what variety they were but I do know she used seeds from last season's pumpkins. She got all her seeds from past crops so I'd say she only had old varieties and Queensland Blues were always the go, so I'd assume they were Queensland Blues. She didn't have a chook pen so looking on top of it wasn't much use either.
It took me about 3 years to get the piston out of that CC. Gawd it was stuck.
Cobba, if you read this book on the CC etc you'll see they used an oiler as a lubricator. If you look real hard at the oiler on our CC it's actually an McCormick Deering, IHC oiler.
http://www.iamnota.net/_media/e:ms2:mcdonald-superdiesel-s_cc_ff-instructions.pdf
 

cobbadog

Registered
Well I went back to the job of removing the fuel cup from the injector body. Had no luck with electrolysis only that it is super clean on the outside. So there was no way that the small grub screw would undo even using an impact socket with the screw driver bit in it so I drilled it out of the way. After reading about so many different ways to achieve what I am trying to do today I went down the road of heating and quenching. Using what Dad used to cal a size C lpg burner I started to gently heat the cup and then quench it in water. I did this a couple of times and the last time I gave it full throttle and got the cup to the dullest of cherry red and then quenched it again. Then I left it sitting in water until next time where I will once again look closer at how much I have drilled out and if any more needs to be removed then will go back to the serious heating again. All the time I have been very gently tapping the cup to see if it shows any signs of moving. This tapping is dangerous as this is how the other cup was broken off the injector body, not because of tapping it directly but by using a lever to lift the body out of the head and the slightest movement sideways breaks the cup off. In the instruction book this is made very clear and that when you remove a stubborn injector it is a case of removing the head and prising the cup up.
So this is my SpacEx clean burn launch today. 20200531_141008.jpg
 

Attachments

cobbadog

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I was also reading through my hand book today about the cause of fuel tanks being re-shaped. Apparently very common when your bottom fuel needle does not seal properly. I only just started reading about this today because my pea brain can only handle so much input at a time so I have been keeping my thoughts on what I have been playing with. So I am guessing that this is the reason why your test the seal by using a clear plastic fuel line first to see if any bubbles rise back up.
 

Darryl

Registered
Nice one Scotty. Once the Pumpkins are picked will they follow you home?
Oddly enough, looking at the oiler on that Mac it appears to be a normal drip oiler and not the usual oil primer. I have seen this done on a couple Macs and even an SE.
The enclosed crankcase engines have the oil priming pump for starting only , the open crank engines have the drip Oiler which is then pumped to the cylinder For constant lubrication.
 

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