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+--- Thread: Starting handle position (/showthread.php?tid=614)
Starting handle position - Adrian Payne - 31-12-2017
Hello All
As the starter dog is just screwed into the crank nose, the position of the dogs is determined by how tight it is done up, the thickness of the crank gear and even how the threads were cut when new. I am proposing to split the starting handle with a thread and use shims to adjust the angle of the handle when cranking.
The question is where is the best position for the handle at engine TDC for maximum effort/speed? 9 o'clock on upswing?
Many thanks.
Adrian.
RE: Starting handle position - Chris KC - 01-01-2018
I'm not convinced you've thought this one through Adrian... My car starts on the handle with no bother, the secret is to have everything else in good shape (specially electrics) then it will start 1st swing. You engage the dogs (wherever they happen to have stopped), nudge it around to the position which feels most comfortable for you then give it a sharp flick.
RE: Starting handle position - John Raeburn - 01-01-2018
(31-12-2017, 12:53 PM)Adrian Payne Wrote: Hello All
As the starter dog is just screwed into the crank nose, the position of the dogs is determined by how tight it is done up, the thickness of the crank gear and even how the threads were cut when new. I am proposing to split the starting handle with a thread and use shims to adjust the angle of the handle when cranking.
The question is where is the best position for the handle at engine TDC for maximum effort/speed? 9 o'clock on upswing?
Many thanks.
Adrian.
Adrian,
I have to say that I'm with Chris on this one, I think you might be trying to solve a problem that doesn't actually exist.
Keep it simple
J
RE: Starting handle position - John Mason - 01-01-2018
I am with the two previous replies. When you crank your engine you feel the compression and that's when you give it the quick flick and the engine fires up.
John Mason
RE: Starting handle position - Adrian Payne - 01-01-2018
Many thanks for your replies and a happy new year to you all.
Your diagnosis is as usual spot on.
Fuelling has been an issue. The 22FZ carb on the car will not idle at slow speed and therefore starting is also an issue.
I have cleaned all the jets and the spindle is in good condition and the float level is correct. I have swapped the carb for a 24t2 and the idle is perfect, thus eliminating a leak in the manifold.
My only observation is that the 22FZ slow running assembly has been gripped with pliers to get the two halves apart and now may not be making good contact with the carb body. I will try machining and sleeving to get this back to perfect.
All this said, this is a mag engine so a certain speed is required to generate a spark. The engine has been fully rebuilt with a rebore and wedged head, so compression is very good. Compression now occurs at 12 and 6 c'clock which appears to be the worst position for getting any real power on the handle.
At what positions do your compression occur on the handle.
Many thanks.
Adrian.
RE: Starting handle position - John Mason - 01-01-2018
Adrian you have me somewhat confused. In my book you should only have one compression stroke per full revolution of the starting handle. This will be at its strongest when the piston reach towards TDC on its compresision stroke.
John Mason
RE: Starting handle position - Alan - 01-01-2018
No, Adrian is right. Cylinders 1&3 fire on first rev, 4&2 on the second. I think you will find 12 and 6 o clock to be a good position for the handle - that's where all mine are and it works ok for me.
RE: Starting handle position - Colin Morgan - 01-01-2018
As I turn the handle from 9 o'clock, slowly at first, it engages at 12 o'clock, then I feel a slight kick at 4 o'clock as the first cylinder sparks, but at the low compression from the slow rotation the engine does not start (and no backfire either!), then I carry on round quicker and flick the handle past 10 o'clock - where the engine fires. A local gentleman called Jim Topping, who has been working on A7 engines since 1949, suggested that the timing on my Ruby is just right when this slight kick is felt on the initial slow rotation - so this is how it is set. (Others, who have seen me starting the car this way over many years, still worry about the risk of a backfire, but then they drive other things, like Morgans.)
Colin
RE: Starting handle position - John Mason - 02-01-2018
A big big sorry I was wrong of course you get two compressions per 360 degrees of turning the crank I was forgetting the other 3 cylinders also turning but on different strokes of the 4 Cylinder cycle.
John Mason