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Other Slow Speed Diesels / Re: McDonald Imperial Super Diesel Crude Oil Engine
« Last post by cobbadog on September 22, 2020, 01:43:00 PM »
Corn Flake packets was my choice of cardboard for the gasket and the head got a quick rub on the cement step, high tech stuff.
As for something to attach to the Mac, I do have a couple of water pumps, no generators here and at one stage I was going to make a Prony Brake for the big Lister and this may still be an option down the track. Just for now I want it to make noise, leak oil and blow smoke.
Other Slow Speed Diesels / Re: McDonald Imperial Super Diesel Crude Oil Engine
« Last post by glort on September 22, 2020, 01:26:07 PM »

You have done well not to have to re ring or re bore it after all this time. I certainly agree, good racing grade oil is essential rather than that Lawnmower quality crap. Make a huge difference to longevity.

I remember mowing the lawn in my early '20s at my Aunts place. Head gasket on the mower blew. was sunday afternoon so no places to get a spare so I got some single ply cardboard from a shirt box I think it was, Got a punch from my uncles  shed and cut a rough gasket shape.
Didn't pay much attention to the inside, figured it would burn away as needed.  Put it on and the thing fired right up.
Thing kept going longer than my aunt and uncle eventually did.

I dumped about a dozen Milk crates of Victa parts when I moved about 3 years ago. Wasn't an easy thing to do actually. Just didn't have any use for them and I'd sold all the complete engines. I do miss the sound and smell of and working on those little engines.
 Still have one mower, must get it out and give it a fire up.  Used to wake up to the sound of those things in the neighbourhood every weekend as a kid.  Now all I hear is large 4 stroke singles on ride ons hammering away. 
Nothing like the sound of the 3 Cyl Diesels in both my Kubotas.

Maybe you could put this engine on an Old slasher and tow that round to make a franken mower?  :0)

Have you anything you intend to couple it up to?
I always prefer to see these engines at Rallies doing SOMETHING rather than just Idling doing nothing. Pumping water round or driving some sort of genny to light a build I think is always  better than just ticking over on their own.
Always figure that can't be great for them.

A rebuilt old engine should have a much longer  life before another rebuild considering the quality of the oils we have now that probably couldn't even been Imagined  50-80 years ago.

Other Slow Speed Diesels / Re: McDonald Imperial Super Diesel Crude Oil Engine
« Last post by cobbadog on September 22, 2020, 12:12:42 PM »
A lot of the things you do to the 2 strokes is a good thing and certainly won't harm anything. I don't over oil the fuel mix but I always use Premium fuel and quality 2 stroke oil and not the old sae30 mixed into the old standard fuel.
My very first Victa a Model 2, I have had since 1967 and threw the engine into a home made mini bike and rode that around the streets of Sydney for a couple of years before putting it back into the mower frame and continued to use it to mow the grass. When I turned 21 I had to rebuild the engine and went out of my way to avoid the 'chromium' rings as they wear the bore too quick. Since that full rebuild the only thing I have done over the years of ongoing use are a number of head gaskets and spark plugs, that's it. It still starts first pull on the rope and cuts the grass and throws it to buggery. Since that engine I have lost count of Victa engines I have repaired and rebuilt and still have many more to do one day.
Other Slow Speed Diesels / Re: McDonald Imperial Super Diesel Crude Oil Engine
« Last post by glort on September 22, 2020, 10:47:11 AM »

When I used to build a lot of 2 Stroke engines, I used to pack the Roller bearings with a good amount of grease.
Also used to put a good smear in behind the rings and wipe Grease around the bore.
For 2 strokes I used to run a rich oil mix for an hour so so break in., People used to tell me that wouldn't let the rings seat properly but I never had a problem with that.  I also put a bit of oil in the fuel of 4 strokes when I rebuild them. Not much, only about 100:1 but I think it helps.
I also pack seals with grease and smear shafts with it before putting them through the seals.

One trick I rad of with 2 strokes was to put a chamfer of about 2-3mm around the edge of the piston skirt. This was said to let the oil film get between the piston and the skirt rather than the sharp edge take it off.  I thought that made a lot of sense and have done it on all engines.
My 2 strokes used to get thrashed but I always got fantastic life out of them.I think that trick was a big reason why.

The other thing was always run plenty of oil. Never gave a damn what the manufacturer said, I ran the oil according to what the thing was doing at the time and always more than suggested. A lot of people seem to have a phobia about 2 strokes blowing smoke. I got worried it they weren't!  If the recommendation was 50:1, I'd run 32. If I was thrashing on the things real hard, I'd run 25.

As long as there was very little or no oil coming out the exhaust pipe, I was happy. harder a 2 stroke works, the more oil you can throw at it.
I like to put grease everywhere in rebuilt engines, even on the rockers and vale stems. It will either burn off or dissolve into the oil depending where you put it and all works well.

Other thing I have always done on a pressurised engine is crank it till the oil pressure comes up.  Astounds me when people fire new engines without doing that. seen plenty of vids where people fire engines and then the oil pump takes a minute or something to prime.  That engine has a short life before the thing has begun.

I'm sure John what you have done may not be to spec but it will work well. You can get away with a lot with old engines but I think people also have a good understanding of things that may not have been thought of back then and changes you have made will probably be for the better.
Other Slow Speed Diesels / Re: McDonald Imperial Super Diesel Crude Oil Engine
« Last post by mike90045 on September 22, 2020, 08:09:15 AM »
Are you pre-lubing parts as you assemble ?   Either with engine oil or with assembly lube ?

Q. How Do You Lube a Cylinder?
     When applying lube on a cylinder, start by cleaning the piston by wiping off the earlier used lubricant from the piston. This is after raising its seat to the maximum. If the cylinder has a bellow or a cover, access the piston by pushing the cover-up. The piston will have some exposed parts, and that is where you apply the assembly lube. After that, distribute the lube to other parts of the piston by lowering, raising, and rotating the seat. Go through this video to see how it is done:
Other Slow Speed Diesels / Re: McDonald Imperial Super Diesel Crude Oil Engine
« Last post by cobbadog on September 21, 2020, 12:12:31 PM »
Thanks Glort, I too am anxious to hear the mongrel run again. Not sure at what level it will run at but the aim is for it to be loud and dribbling oil somewhere and blowing smoke. :)
I have a list of things that might be wrong in what I have done and the cam gear rebuild done to a guess shape is high on the list of things. The spring tension for the needle in the injector is another. Tomorrow I want to make some caps for the valves and with a special design to do the job so will take some pics of the design. It is a combination of the originals and something new.
Other Slow Speed Diesels / Re: McDonald Imperial Super Diesel Crude Oil Engine
« Last post by glort on September 21, 2020, 11:54:40 AM »

Can't wait to see the full feature length movie of it's first Fire up!

Going to be still chugging along long after I'm gone and probably better than it left the factory.
Other Slow Speed Diesels / Re: McDonald Imperial Super Diesel Crude Oil Engine
« Last post by cobbadog on September 21, 2020, 07:42:22 AM »
Got the rings onto the piston and gapped them using the cut off wheel of my grinder. (that will be a talking point).
Fitted the piston then the crank into place and connected the big end to the conrod and then to the crank. Made a new gasket out of 1.5mm paper for the side cover that houses the other crank main, fitted a new oil seal and then put the cover on and tightened it. The rings a have a good hold of the bore but once I have it moving I can move it with a struggle by turning the crank by hand. Once the flywheels are on it will be a lot easier.
Listeroid Engines / Re: timing adjustment for WVO to reduce carbon build up
« Last post by glort on September 21, 2020, 05:02:36 AM »

A quick and easy way to bump the timing would be just add 10% RUG and see what happens.

sorry, what?  change the timing by 10%?  as in change where the injection happens so it's 10% further around the flywheel?  Is there an easy way to translate that 10% to twists on the timing nut?


Add 10% Gasoline ( RUG/ ULP)  to the oil .
This will advance the timing because the petrol will light off before the oil under compression and cause the ignition cycle to happen earlier in the stroke effectively brining the timing forward.

You said you haven't been able to start on  WVO but then you said it starts easy... on Diesel I presume.

Unless you are in Freezing temps, you SHOULD be able to start on WVO.

If you can't, likley candidates are Compression, Injector and or Pump and to a lesser degree, Timing.
Try the 10% Petrol and see what happens with that.  It definitely should be able to start on a 10% Mix and if it won't, it's the engine not the fuel.  If it starts easy on Diesel, should start easier on a blend.  Mix up say 25L and run that as you would use the engine normally. See what happens. If you have the carbon issue it's the pump or injector I'd say. Could be compression but 10% blend will solve a lot of problems.

If the thing runs OK on the blend, just make that it's standard fuel. In summer you should be able to cut back to 5%.

I ran vehicles for Years like that and blending is a far better option IMHO than stuffing round with 2 Tank systems.
 Did that for a lot of years too before waking up to the best way.

This is going to be a process of elimination. Try the 10% first, see how that goes then look at the next step once you have seen how that works.
Everything else / Re: Coolant change
« Last post by veggie on September 20, 2020, 07:40:36 PM »

Spotless !
I bet the inside of your engine cooling passages are just as clean.
Nice work.
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