JB Atoms

Well I've made a new collar and assembled the engine, I can get it to fire but will it run, will it hell! I've been battling for 2 days now in 40+ heat and all I'm getting is tired!
My next plan is to assemble the engine that was sent as a sample and see if I can start it.

Well I didn't expect that as they were always easy starters and ran beautifully . Even on straight fuel And with very little mess. I wonder what it can be .Fuel supply ,timing. tight fits,Low compression or what? Would mixed up parts cause it ? Unlikely I know but it is a thought.It must be disappointing for you Tony after all your hard work.Have you tried a heavy prop on it ? Gyroscopic force etc Good luck John O/T

Tony just a thought what is the orientation of the cross holes in the spray bar of the NVA, If drilled right through they should be horizontal across the venturi. If a single hole it should face straight down. If Granny has already sucked these eggs I apologise
John O/T

2 hole needle valve, the holes are across the venturi, check!
Timing, controlled by the hole in the crankshaft, same as the sample, check!
Plenty of suck when I put my finger over the venturi and flick, check!
Compression, plenty, if I wind down the screw I can stop it from firing, check!
Leakage from the back plate or cylinder liner, nothing, check!
Propeller, either 8 or 9inch, runs fine on my Mills 1.3, check!
I'm beginning to think the problem is fuel related, 40^o and 3,000ft, if I take the lid off my Ether bottle I can see the Ether boiling. My next intention is to assemble the complete engine and attempt to start it, if it starts then I can start swopping exterior parts across.

You'll have to pressurize your workshop to 1 bar, Klippy! [badass]

You seem to have covered everything Tony. Even one I forgot about.As Eric says it could need 1 bar in your workshop LOL/ Is the Mills 1.3 running on the same fuel or was that a while ago?Could be you've lost some ether as you suggest If you don't get them to run don't worry Just parcel 'em up and send 'em back and let me know what I owe. Polished up they'll make nice ornaments on my shelf..LOL [badass] An after thought have you tried them at night when it's cooler? :evil:

Result! The supplied complete engine runs.
Gets very hot and any attempt to refuel within 10mins just results in the fuel boiling out of the tank. It runs for about 60secs on a full tank driving a 9x4 propeller. I can't get it to start by hand, but then I never was very good at starting, just a single touch with the starter and she's away.
Now I've got a runner I'm going return to the other engine.
I make a fresh batch of fuel each time I'm going to try something. 60mls at a time, when I've finished I pour the contents of the plastic refueling bottle back into a 100ml glass bottle.
My new CS Mill 1.3 runs on this mix as a cross check, but also won't start by hand, but then I'm sure that's me!

Dear! Dear!
Can't start a Mills 1.3 by hand?
I would have thought that was almost impossible.
I have started mine by hand and holding it in my hand! :woohoo:

Well, I've run a prime off in an Ollie Tiger whilst holding it in my hand - deliberately. I even had a Supre Tigre 46 fire up without the plug energised in my hand - but that was an accident! Unless K's atmospheric conditions (conditions way outside my experience) are to blame I just can't understand it.
Mike

Nor me Mike as were lovely engines to run and I've run off the prime in them in my hand too. Also run Cox .020 and .049 s in my hand holding the tank.Not for too long though. They do get hot.LOL. While on the subject of engines I thought this may interest some of you . Dutch guy You tube name Varic 000. Has one hell of a collection seen on other blogs.
P.S. does anyone ;know thread sizes of AMCO .87 Crankshaft and comp screw .Also what type of solder was used to attach transfer passage and intake tube to the cylinder.At some time in the future I would like to borrow a spinner to copy if any one can spare one for a short time. As I say in the future.

Interesting discussion, as I said, even as a pre teen I never had any engine that could be called easy starting. My mate Peter had to start his Mills 1.3 by hitting the back of the prop with his chicken stick!
In my current situation I am convinced that 9/10 of my problem is fuel, I can't import any and it's not made locally, diesels were never popular here. The one item that all fuel manufacturers seem to add is Isopropyl Nitrate, which seems to be another name for Amyl Nitrate (please comment anyone) This additive I know improves starting characteristics.
Paradoxically Amyl Nitrate is commonly used in the sex industry but there's no sex shop in Lephalale!

Great topic, klippy you could open a sex shop then import your own, :woohoo:

John, the two are similar and can be used in similar ways – as far as we are concerned as ‘dopes’ for diesel fuel. The formulae are:-
Isopropyl Nitrate C3H7NO3
Amyl Nitrate C5H11NO3
Note the additional hydrogen atoms in AN. I think the sex shop usage is probably amyl nitrite, not amyl nitrate. Nitrite is a constituent of one of the ‘recreational’ drugs known a poppers (or so Wiki tells me!)
Mike

Whoops - should have directed that reply to Klipy, not John - apologies. Oh, and by the way Amyl Nitrite is used as a heart stimulant in some medical procedures.
Mike

Klippy
I am sure the lack of a fuel dope is the cause of your hand starting problems.
From what I remember Amy Nitrate was the 'magic' ingredient in Mercury No 8 and it ran all my diesels superbly!