Ignition Timing *again!*

[Castanley]

I say *again* because I know this subject has been discussed to the n'th degree in this forum but I'm still having an odd experience with mine that I can't quite find the solution to.

Background- my moggie is a 1954 Series 2 with an 803cc engine. Mechanically in pretty great condition except the whole ignition system was ancient and in need of a major overhaul. I've never tackled an ignition system before but the work done was as follows... Removed dizzy and sent vacuum unit off for a professional refurb (it was leaking). Dizzy cleaned up & lubricated, then refitted with new points, condenser, rotor & cap. I made up a new set of HT leads, fitted a new coil and 4 new spark plugs. Engine fired up and ticked over nicely, now to tweak the timing!

A helpful friend of mine lent me a nice Snap-On timing tight with advance control knob.
I disconnected the vacuum pipe and capped it off, warmed up the engine and connected the timing light. Now, my engine has the 3 timing 'spikes' next to the pulley. A long one for TDC and 2 shorter ones for 5 & 10° BTDC. With the engine at idle, the strobe showed the timing notch on the pulley to be WAY past all those marks, so very far advanced I assume? The mark was rock steady and not wavering though which I gather is a good thing.
Ok so with the pinch bolt loosened I gradually rotated the dizzy anti-clockwise as viewed from above until the revs started to drop and the engine started to idle a bit rough. Looking back at the marks I still hadn't got anywhere close to the timing marks! I used the advance knob to see how far off I was and it was around 30° BTDC!
I advanced the dizzy again very slightly until it idled nicely and I took it for a test drive. It seemed ok but I just don't know what signs to look for. I just can't help thinking I'm way too far advanced but I could do with some wisdom being thrown in my direction!

Sorry for the essay but I wanted to get all the relevant info down. Thanks in 'advance'!

Chris

[kennatt]

put the timing light back in the drawer,take car out with pinch bolt just holding dizzy, advance it a bit at a time until the engine starts to pink under acceleration ( slight light rattle) stop and retard slightly test again repeat ,until the noise stops under hard acceleration stop and tighten the pinch bolt. the timing is now perfect for normal road ,day to day use.

[oliver90owner]

Same as kennatt, but using the timing light to retard the engine by a small amount when pinking starts, and to know precisely where the timing is to be set on the next occurrence for the need of setting the timing.

[Castanley]

Lovely jubly, thanks guys.
So ignore the timing marks and workshop manual then!
Would the same have been true when these engines were much younger or is this just a quirk of the A series?

I have a handy steep hill down the road I can use for a 'pinking test'!

Chris.

[Pete Bags]

Lovely jubly, thanks guys.
So ignore the timing marks and workshop manual then!
Would the same have been true when these engines were much younger or is this just a quirk of the A series?

I have a handy steep hill down the road I can use for a 'pinking test'!

Chris.

When I fitted electronic ignition, I used the 'book' figures to set the timing - the pinking was terrible, so did exactly as Kennatt suggested and the engine now runs as sweet as anything. I wonder if this difference between book and real world settings is due to a mix of electronic ignition, modern fuels, slightly worn parts etc?

[Edward1949]

I've always fancied a manual advance/retard control on the dashboard, as fitted to many pre-war cars. It could be used to find the timing "sweet spot" while climbing a moderate hill in top gear, then locked until next needed - eg after an overhaul, or change of petrol grade.

[Castanley]

Ooo yes, a cabin mounted advance control would be a great idea wouldn't it!

So in summary am I correct in my thinking that rotating the dizzy clockwise as viewed from above will advance and anti-clockwise will retard? And I want to advance it as much as possible without it pinking?

Chris.

[liammonty]

I've always fancied a manual advance/retard control on the dashboard, as fitted to many pre-war cars. It could be used to find the timing "sweet spot" while climbing a moderate hill in top gear, then locked until next needed - eg after an overhaul, or change of petrol grade.

Alas not - it needs to be adjusted on the move according to engine load and speed. Too much advance up hill under load, pinking and potential damage to pistons etc, then if you don't advance it sufficiently as you are going down the other side of the hill the engine will be sluggish and run hot. Conversely, timing too retarded under load can cause horrible bottom-end rumbling and damage. It's a bit of an art to get right when you are dealing also with a crash box, next to no brakes etc. etc. in a car of such vintage.

The job of the lever was to advance and retard the timing manually with engine speed and load - a task done totally automatically by the centrifugal and vacuum advance built in to the distributor of a Minor 1000!

[liammonty]

So in summary am I correct in my thinking that rotating the dizzy clockwise as viewed from above will advance and anti-clockwise will retard? And I want to advance it as much as possible without it pinking?

Chris.

Yes and yes. Just be aware that on some cars it can actually be hard to get them to pink audibly, even when the timing is massively over advanced. You’ll notice if it ends up way too advanced as the engine will lose power.

[kennatt]

what seems like an eternity ago,I learned to drive in my dad Alvis TA14 ,it had an advance and retard lever on the side of the wheel,Retarted it to start when cold,then put it into the central position when up to temp, including judicious fiddling with the choke. Couldn't hear it when it was ticking over only way you knew it was running was a slight vibration through the floor. How things have changed eh.(Wish I had it now probably worth a fortune)

[Myrtles Man]

what seems like an eternity ago,I learned to drive in my dad Alvis TA14...
...(Wish I had it now probably worth a fortune)

Surprisingly not; several for sale on Car and Classic at the moment for around the £14K mark, comparable with the current price of top-end Moggies!

[Edward1949]

I've always fancied a manual advance/retard control on the dashboard, as fitted to many pre-war cars. It could be used to find the timing "sweet spot" while climbing a moderate hill in top gear, then locked until next needed - eg after an overhaul, or change of petrol grade.

Alas not - it needs to be adjusted on the move according to engine load and speed. Too much advance up hill under load, pinking and potential damage to pistons etc, then if you don't advance it sufficiently as you are going down the other side of the hill the engine will be sluggish and run hot. Conversely, timing too retarded under load can cause horrible bottom-end rumbling and damage. It's a bit of an art to get right when you are dealing also with a crash box, next to no brakes etc. etc. in a car of such vintage.

The job of the lever was to advance and retard the timing manually with engine speed and load - a task done totally automatically by the centrifugal and vacuum advance built in to the distributor of a Minor 1000!

I probably didn't make it clear - I meant that the existing distributor would remain with fully functioning vacuum advance and centrifugal weights as normal. The manual tweaking of timing while driving would be a one-off task, the manual control would then be left undisturbed until required in the future. It would be an easier, more accurate way of finding the best timing on road test compared with continually stopping, opening bonnet, adjusting distributor.

[liammonty]

Ahh - now that would be handy!!!