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Help! Timing?
#1
Hi, I have a A7 special which I have had for a few years.  I decided to rebuild the engine having found a number of issues and post rebuild had it running (therefore I would assume nothing major is wrong?), however, for the last 12 months I have been unable to start the engine at all.  I have had two or three modern car mechanics look at it and they all tell me it should run!

What have I done:

I believe I have set the static timing correctly, e.g, after the compression stroke on one turn the engine a further turn and a half and then find TDC using a probe (pipe cleaner!).  The set the dizzy so the correct segment is lined up and set the points at 12 thou, refitted the leads 1342 after setting the plugs at 24thou.  Turned the engine over a quickly get a single backfire followed by the engine trying to catch but not?

I know I'm really close but could do with a little advice please?

Thank you.
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#2
If it backfires and tries to catch then that indicates you've not got the timing correct. Forget the 'turn the engine a further one and a half turns' business and go for the simpler method.

Find the compression stroke on No1 (No 1 is the front cylinder) by putting your thumb over the plug hole. As soon as you feel compression, stop. With your probe down the plug hole touching the top of the piston, continue to turn the engine until the probe/piston is at its highest point. You've now found TDC on the compression stroke for No1. Without turning the engine any further, set your distributor so that the rotor arm points to the contact for No1 on the distributor cap. It helps to mark that point on the side of the distributor. Clamp the distributor up and assuming everything else is in order, the engine should start.

At this setting, it will be a bit retarded but once started, that can easily be adjusted.

Steve
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#3
Thanks Steve,

I'll have a go in the morning and come back too you!

Paul
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#4
High or low compression head

Auto or manual advance, if auto which?
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#5
Having just fitted a newly rebuilt engine into my Ruby, which I new was running after collecting from the engine builder, I was b*ggered if it would start, Checked all the obvious stuff
then found battery was flat after sitting doing nothing for ages, charged the battery overnight and guess what, woke all my neighbors this morning as it started first swing, on short exhaust pipe, happy days !!!!
RIP Stirling :-(
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#6
Its a non standard Supalloy head, manual advance and retard I think?
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#7
Hi

Is the petrol fresh? Regards Peter
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#8
(12-04-2020, 03:04 PM)Gem4373 Wrote: Hi, I have a A7 special which I have had for a few years.  I decided to rebuild the engine having found a number of issues and post rebuild had it running (therefore I would assume nothing major is wrong?), however, for the last 12 months I have been unable to start the engine at all.  I have had two or three modern car mechanics look at it and they all tell me it should run!

What have I done:

I believe I have set the static timing correctly, e.g, after the compression stroke on one turn the engine a further turn and a half and then find TDC using a probe (pipe cleaner!).  The set the dizzy so the correct segment is lined up and set the points at 12 thou, refitted the leads 1342 after setting the plugs at 24thou.  Turned the engine over a quickly get a single backfire followed by the engine trying to catch but not?

I know I'm really close but could do with a little advice please?

Thank you.

Bit of of a shot in the dark but I remember once putting an engine together in the Austin dealers workshop in Thesalonika ( 1964) — the crank had broken after several days in first gear coming through Macedonia. Anyway, to the point, we assembled the engine and put it back into the chummy. It fired a bit but wouldn’t tick over etc. Turned out we had put the timing gears back with the camshaft gear 360 degrees wrong — not saying you have done this but it’s worth a thought?

Charles

(12-04-2020, 05:52 PM)Charles Levien Wrote:
(12-04-2020, 03:04 PM)Gem4373 Wrote: Hi, I have a A7 special which I have had for a few years.  I decided to rebuild the engine having found a number of issues and post rebuild had it running (therefore I would assume nothing major is wrong?), however, for the last 12 months I have been unable to start the engine at all.  I have had two or three modern car mechanics look at it and they all tell me it should run!

What have I done:

I believe I have set the static timing correctly, e.g, after the compression stroke on one turn the engine a further turn and a half and then find TDC using a probe (pipe cleaner!).  The set the dizzy so the correct segment is lined up and set the points at 12 thou, refitted the leads 1342 after setting the plugs at 24thou.  Turned the engine over a quickly get a single backfire followed by the engine trying to catch but not?

I know I'm really close but could do with a little advice please?

Thank you.

Bit of of a shot in the dark but I remember once putting an engine together in the Austin dealers workshop in Thesalonika ( 1964) — the crank had broken after several days in first gear coming through Macedonia. Anyway, to the point, we assembled the engine and put it back into the chummy. It fired a bit but wouldn’t tick over etc. Turned out we had put the timing gears back with the camshaft gear 360 degrees wrong — not saying you have done this but it’s worth a thought?

Charles

Hello Gem — reading your post again I see you had the engine running ok before — so ignore my contribution!

Charles
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#9
Statically it should be just firing at TDC. Do what Steve said but then find the screw that locks the distributor base plate and slacken it a little so you can rotate the distributor body. Put a blue Rizla between the points and rotate the distributor body till the points shut and grip the paper; then rotate gently till the paper (pinched between your other thumb and forefinger) just slips out - here the points are just opening and the spark occurs. 'Correct' timing is only found by experimentation but if that doesn't start timing isn't your problem.
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#10
Charles did you mean 360 deg ,which would put it back where you started, or should it read 180 deg?
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