Ignition timing

Post by **biomed32uk** » Wed Feb 24, 2016 7:10 pm

I know this is much discussed and I have read lots of posts on it.

To try and set it I have let her warm up, put the idle up to about 2000rpm, with a tacho on the engine rotated the distributor clockwise , until the revs stop rising and backed it off a smidge.

Runs well and smooth when ticking over and revving, not tried driving her yet as she's not ready for the road yet.

My timing light has decided not to play, but could someone do me a confidence check and let me know roughly what their timing is at normal tickover, 800rpm or so please. I know its all academic and every engine is going to be slightly different but I would appreciate the check, so I have a rough idea of where it should be.

I really don't want to screw the engine up, after the disaster last year. From where the dizzy was it will be greatly advanced, but she was driving fine last year until the failure. I am used to having procedures and settings available from my line of work, comes hard just twiddling and doing it by ear.

Post by **bmcecosse** » Wed Feb 24, 2016 7:18 pm

2000 revs is too high to be setting the dizzy with no load on the engine. Do it at normal idling speed - nearer 500 revs if it will run - and twiddle for 'best idle'. Should certainly be no more than 5 degrees static. Is the vacuum advance working ok? And the mechanical advance is ok ? ie if you twist the rotor arm - it springs back ok? Always road test for any 'pinking' - it must NOT.. Just 'not quite pinking' is ideal when pulling strongly in a high gear.

Post by **biomed32uk** » Wed Feb 24, 2016 7:35 pm

Certainly not happy with how it is now, really not sitting right with me at the moment.

I got the procedure off the minispares site, I can't do a static check as I am electronic. I am sure it is way too advanced now, but the revs certainly rose when advancing it, if it too advanced I would have thought they would have dropped off as the engine starts fighting with itself.

Would just like a rough figure at tick over what I should be aiming for with a strobe on it, one downside of electronic is you cant do a static time. Would like it to be somewhere near so I can then adjust finally on a road test.

Post by **liammonty** » Wed Feb 24, 2016 8:03 pm

Why not use the settings as per the workshop manual (surely you have one after rebuilding an engine and gearbox?) as a starting point, at around 3 degrees BTDC?! Check it, but I think that it's below 600 rpm (when mechanical advance begins) and you should disconnect the vacuum advance too while you're doing it. That's roughly what all of my standard-engined Minors have run at give or take a couple of degrees. The risk of using the widely advocated 'just advance it till it pinks then back it off a bit' is that I've had a couple of engines that I couldn't get to audibly pink despite ridiculous amounts of advance, and if run like that they would have destroyed themselves fairly quickly. And before people say that it was due to my engine having poor compression, that wasn't the case

.

Once you're happy with it like that, you can tweak it by ear the odd few degrees without fear of destroying the engine.

Post by **biomed32uk** » Wed Feb 24, 2016 8:56 pm

Good point really, it is spec'd as 6deg BTDC stoboscopic in the manual, and bearing in mine unleaded may need retarding a touch something is very out. Must have a ridiculous amount of advance now. Time to check right through it again.

Post by **liammonty** » Wed Feb 24, 2016 10:19 pm

Good luck. Definitely better safe than sorry!

Post by **bmcecosse** » Thu Feb 25, 2016 5:08 pm

It's VERY important to check the vacuum advance is working - or it's a waste of time doing anything. The difference between 3/5/6 degrees when idling is insignificant. The total advance when running under load at 3000 revs should be somewhere between 30 and 35 degrees. Some of this from the mechanical advance (ie the bob weights) and some from the static advance, Under load - the vacuum advance is negligible of course - it comes in to play at part throttle only - depending on the vacuum in the manifold.

Post by **biomed32uk** » Sat Feb 27, 2016 8:28 am

Good point that, it was working fine last year, tested it and I have a small leak from where the pipe attaches again. I have the one with the threaded connector and copper tube and have always had a job getting it to seal, I made a new olive for it as well.

The actual vacuum unit is OK and not leaking but do they age over the years?, I can imagine the diaphragm going hard, heaven knows how old it is.

Just wondering if it may be time to pop a new one on.

Post by **Trickydicky** » Sat Feb 27, 2016 9:31 am

If it's leaking from the threaded part maybe try some Ptfe tape to help seal it?

Post by **bmcecosse** » Sat Feb 27, 2016 11:08 am

They all fail within 20 years - the test is to suck the pipe and see if the baseplate moves and returns when you stop sucking. Leaks of course need to be stopped or it won't be doing the job.

Post by **biomed32uk** » Sat Feb 27, 2016 1:02 pm

Baseplate is moving, I use a syringe to generate the suck, got a very unpleasant mouth full of something last time I provided the vacuum. Whatever you can see it slowly rotate back. Some soapy water and gentle postive pressure and its leaking from where the pipe enters the the top of the nut.

The inside of the dizzy is fine, that was stripped last year, cleaned, lubricated and rebuilt.

Just wondered before they fail does the performance of the capsule get tired.

Post by **bmcecosse** » Sat Feb 27, 2016 1:08 pm

They often go hard - or just leak... As long as the baseplate moves - it's fine. And the mechanical advance is ok? Springs in place and rotor arm springing back when twisted?

Post by **biomed32uk** » Sat Feb 27, 2016 6:12 pm

Well it was well worth a check, I have one of these little hand held vacuum pumps, which I got for assisting with brake bleeding.

Took the pipe off and fitted that on and the unit is leaking, so the answer to my question about it needing replacing is yes. As the new one comes with the push on pipe that can replaced as well.

Dizzy is perfect with the mechanical advance, springs are in place, the slightly looser spring is in the right place so that's all in fine order. Hindsight says that I should have tested and replaced that last year when I stripped the dizzy, quite how or why I over looked that one I don't know

When I strobe the engine the timing is steady, certainly not scattering all over the place.

Vacuum capsule to be ordered. Thanks for all the tips and help.

Post by **bmcecosse** » Sat Feb 27, 2016 6:55 pm

Of course you could just get a complete new dizzy and have no more worries..... http://www.ebay.co.uk/itm/170571309091? ... EBIDX%3AIT

Post by **liammonty** » Sun Feb 28, 2016 12:53 am

Ahh, the replacement of a known working part with a likely-Chinese manufactured cheap replacement with the added benefit of electronics as an additional source of potential breakdown. No more worries, well, not for the first few months perhaps! Perhaps you should replace your coil at the same time

You'll see with the strobe whether it's advancing as it should mechanically - I'd suggest it's best left as is, albeit with a new vacuum unit, if the advance is stable and doesn't 'wander'.

Post by **bmcecosse** » Sun Feb 28, 2016 11:27 am

I think they are made in India - and no - keep the good old coil. Some of the modern coils are poorly made - bad advice there I think... Many on here are using these dizzies and reporting excellent results and literally 'no more worries'.

Post by **liammonty** » Sun Feb 28, 2016 11:37 am

The comment was made with tongue firmly in cheek, BMC

. The Lucas-branded distributors are made in India for sure, but I'm not sure about the accuspark ones. I'm just dubious of the level of quality possible when the whole thing costs £60...

Post by **bmcecosse** » Sun Feb 28, 2016 11:52 am

Well - there are many good reports of them - over a number of years. Some who have bought the electronic 'conversion kit' have had problems - but I suspect due to fumbled installation. Hence I would never suggest anything other vthan the complete new 45D dizzy. Fit and forget!

Post by **dalebrignall** » Mon Feb 29, 2016 4:35 pm

all i can say is ive fitted 2 accuspark ones and had great results

Post by **biomed32uk** » Mon Feb 29, 2016 5:56 pm

I will just replace the vacuum unit, I have fitted the Accuspark conversion which has been there two years with no problems. The rest of the dizzy is fine so a new vac unit and the jobs good.

Set the timing on her yesterday at 600rpm and best around 7 degs btdc or so, at 800 rpm thats giving about 11-12degs btdc. Any less than the 7 degs and she runs really rough and lumpy.

Biggest mistake when fitting these conversion modules is when applying the white heatsink compound to the bottom of the module people trowl the stuff on so its oozing out everywhere, that has the opposite effect of thermally insulating the module from the plate rather than assisting the conduction of any heat. Just a wipe, less is more.

Now awaiting a new vac module. Put the front bumper assy on and she can go for a road test.

Morris Minor Owners Club

Ignition timing

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