McDonald Imperial Super-Diesel

Thats a good idea, using a low pressure cap, say two pound per, and if the return line builds up too much back pressure (I assume thats where it originates) simply vent to the atmosphere.

All you need is a breather ,a piece of pipe in a gooseneck .....if that much compression blows back thru the pipe ,there is no way the motor will run anyway......This used to be a problem in the WW2 Cummins motors in the Federals .....if compression blow back thru the injectors ,the fuel system would stop injecting fuel ,and the engine would lose power and stall.......which was beyond the fixing skills of any bushie.

There is no return line on this primitive engine only a line in. If the needle does not seal properly you get the compression back into the tank. As for the tank lid, I have an idea to try out which is similar to the original design of a slight twist turn to fix it in place. Final design is still inside the puta on my shoulders. In the immortal words of Black Adder, "I have a very cunning plan". Just hope it works, if not I have a welder.

I WON, I WON !
I got the bastard at last. Safely apart now just zapping the needle from the tube and it is ready. A heap of filth was still inside the cap and could only get in there via the fuel system. What worked was the freezing of the body and heating the cup. I did also find a small amount of the old screw in the recess that was holding things up a little bit once I got it to twist and it showed up so I dug it out.
Also finished off the lid for the bomb proof fuel tank.
It is a good feeling when things go forward after a long challenge, so happy I could shit!

That is scary happy...... thanks for the description, I am nearly that happy myself just reading your success.

And about the fuel cap, several of the old tanks an or fuel necks I have on things have a 1/4 or 1/2 turn lock, a bit like a radiator, some internal some external, would a discerning scap dealer have some suitable donor?

Cobbadog,
I am still waiting to hear what the defrosted injector body tasted like for dinner? Was it roasted in the oven, or did Cobbarette boil it for you?
Did you have it with tomato sauce or gravy? :sick:

Keep up the good work, you are succeeding where a lesser person would have failed!

If one was handy, the fuel tank filler neck from any old Inter, or Dodge. This part invariably outlasts the rest of the truck and could be cut down to any height one desires. Caps are still available new from Iveco, if you wanted a shiny, undented one.

Jarrod.

Apparently I didn't need any extra iron in my diet last night as we had chook. So the injector escaped the eagle eye of Cobbarette.
Not worried about the washing of the nickers, I don't do the washing.
Yes I am thinking of making this lid into a 1/4 turn lid, maybe even 1/8" depending on how excited I get and we know how excited I can get and the results. (more washing powder may be needed). Something tells me that something new and unmarked would be way out of place on this fine specimen of an engine. I think I will stick with the rough n ready approach.
Got to sort out the valve guides, maybe, as they show a bit of wear. I know I can get new steel valves with a 7/16" stem which was original but not oversized unless it is a special order. If that is the case I can keep these guides and have them reamed out to size or find some cast iron and try to make some new guides which in this case are not just a straight tube pressed into the head. Part of the guide sits above the head and positions the bottom of the spring then it is machine down in size to got through the head. Just for fun they are both a different overall length. One finishes just inside the port and the other projects further into the port. So if I make new ones with my ability I may need to start with a ton of cast to make a couple that would weigh a couple of hunred grams. I will look into this further next week with a supplier of valves.

Tomorrow I will take the head with me back into town and see if I can get him to accurately measure the guides and I am looking at getting some over sized valves made, this may be the simplest and easiest way to go.

Having endured the day without power because they replaced a transformer down the bottom of the street I could not do the jobs I wanted to do but did get to shuffle a heap of curtaining fabric around in Dee's work room. So when I finally got to play mode I had a go at removing the needle from the stem after being in the electrolysis tank for a couple of days. It did come out sparkling clean but obviously still a lot of carbon on the inside. I have easy access to the bottom of the needle via a hole where the fuel would run into the cup, also can get a good hold on the top of the needle but it is not budging yet.

In the McDonald hand book of instructions it does mention a few times to use 'kero' to clean the fuel system parts in. Why this is suggested rather than clean diesel is a mystery to me. So it is soaking in some kero at the moment. I am also now eyeing up my ultrasonic tank as I can actually touch it now some fabric is gone. so find a plastic jar and some petrol and spark it up, literally not physically.

Carbie cleaner or thinners dissolve carbon.

That injector is fighting every thou of the way.....

Jarrod.