Setting static timing with no reference

[edd_barker]

Hi all,

As I have changed my crankshaft pulley for a mini dampened one, I no longer have any relevant timing marks to work from. I need to completely reset the timing from scratch, which I have never done before. I understand the principle.

Can I get away with finding TDC by looking at piston through the spark plug hole? Do I then need to buy a 12v test light to determine when the contacts are open? I am scouring internet for a dummies guide but not much going so far...

Many thanks,

Edd

Edit: piston stopper technique looks worth a shot?

[philthehill]

Turn the engine over until No: 1 piston starts to come up on the compression stroke.
The compression stroke can be identified as when both No: 1 inlet and No: 1 exhaust valves are closing/closed and the relative rockers have clearance.
With No:1 spark plug removed place a blunt rod/screwdriver into the spark plug aperture and turn the engine until the piston pushes the rod/screwdriver to its highest point. Take care so as not to jam the rod/screw driver between piston and cylinder head/valves.
(There is absolutely no need to buy any special tools to determine TDC on compression).
You now have the approx TDC on the compression stroke.
Mark the pulley and timing cover as a base line for future reference.
Whilst it may or may not be exactly spot on as regards TDC (this approximation is because the crankshaft can turn through several degrees at TDC without effecting the piston movement) the crankshaft position is sufficient to time the engine.

Whilst the use of a low amp 12v bulb in a holder to determine when the points start to open is a bonus - so long as the points have been set to 15thou it is possible to determine visually when the points start to open which is sufficient to get the basic timing setting for engine starting.
Fine tuning of the ignition can be determined after running by turning the distributer to advance or retard the ignition.

[edd_barker]

Thanks Phil, that makes perfect sense.

So I will find approx TDC, then am I setting the points to open just before TDC?

I have just realised that my vac advance is not working! Sucking on the pipe produces no movement of the plate. I was planning on switching to electronic ignition anyway at a later date, and recommendations for new dizzy?

Many thanks,

Edd

EDIT: currently have a 25D fitted I am 99% sure!

[philthehill]

Edd
As you say - Set the points to open just before (approx) TDC - that will be sufficiently accurate to get the engine started.
The static timing is 3 degrees before TDC with a 25D but it is better to set the final ignition timing after running the car and trying slight advances and retards until the car performs best without pinking.

[David W.]

Note that you will be turning over the engine by hand when looking for TDC. As the #1 piston comes up, block the plug hole with your thumb, and you will be able to feel the compression.
I use something softer than a metal rod. The small spray tube from a can of brake cleaner, carb cleaner etc.
When you determine TDC, mark a reference point on the pulley and timing chain cover. Back the crank off (Clockwise when viewed from the rear) about a cm. That will put you in the ball park.
Loosen the distributor just enough to allow you to turn it. With your device, 12v light, ohmmeter etc, turn the dizzy until the points are just opening.
You are ready to start it up and adjust timing by ear for best performance.
As for your vacuum advance, take the dist cap off and be sure the actuating spring from the diaphragm is attached to the points plate. Mine was not. If the diaphragm is connected to the points plate, and you see no movement when applying vacuum, then that unit is shot.

[rayofleamington]

For finding TDC and doing the timing you don't need to be on compression stroke on #1. It can be #1 on exhaust stroke as well.

If it's 180 degrees out on the cam, it is 360 degrees on the crank (#4 will be on compression stroke but #1 still at TDC. The entire process is identical though .

To get close - take off the dizzy cap until rotor arm comes round towards #1 or #4 lead position.. then you'll feel the compression on starting handle assuming you still have the dog..

I've set statically at 5 degrees - but first put the vernier nut to middle of adjustment.
Then you can go either way for manual timing until it's away from pinking.

[oliver90owner]

While an approximate TDC will get you going, the really accurate method for finding TDC is with a dial gauge. One makes a mark on the way up and another at exactly the same reading on the way down. Bisecting those two points will be TDC. There are relatively inexpensive dial test indicators that can be used, or modified to be used, through the plug hole. Clearly easier with the head off.

[liammonty]

Absolutely right, and essential for determining TDC accurately, for example when setting cam timing. Totally unnecessary for what Edd is wanting to do though.

[oliver90owner]

Sorry. I thought I made it clear that approximate will do to get the engine running.

[liammonty]

True - given that it was the first thing you said, I guess it should have been fairly obvious . It's getting late!

[andypocock]

Come on chaps, what's all this talk of lights and ohmmeters? This is a Morris Minor. You stick a fag paper between the points and pull very gently. The points let go of the fag paper as they start to open.

[David W.]

The old saying is:
"This is measured with a micrometer, marked with chalk and cut with an axe."

[edd_barker]

Thanks for the advice all.

Plenty of info enough to get it running I hope! Should be back out there Thursday.

Regarding a new distributor, it looks like most of the modern manufacturers sell a 45d as an upgrade. Is this correct for my engine? (1098 +040, 12G940, HIF38, standard cam/exhaust).

If fitting electronic ignition, I assume that I do need a test light to know when the points are opening. I think I will try and get it running on the current distributor dislike lack of vacuum advance, then upgrade after that

Many thanks,

Edd

[Declan_Burns]

Edd,
The most of the electronic ignition units have no points and no test light. The 123 Ignition does have a light but it is very expensive.
The cheap electronic ignition distributors on the market are in my opinion not the way to go. The distributor caps are absolute rubbish. I have replaced two of them in the last year.
You might be better off sticking with points.
Regards
Declan

[liammonty]

I totally agree with Declan on this one. I've heard of several failures of the cheap distributors (though many will tell you they're fine in their experience) and to be honest, they offer next to no advantage over a well set up standard distributor. the disadvantage is, of course, that if they do break, you are left totally stuck, whereas with the original system, roadside repairs are easier.

I've also had 25d and 45d distributors, and I'm not really sure why the 45d is considered an 'upgrade' as I've never had any issues with the 25d.

If you do go electric, I would go with the Aldon/Pertronix system (I've run them on my T2 VW and they have been reliable), or a 123 distributor, which have great reports, and on some versions you can adjust the timing curve (which would be useful with your upgrades). If you stick with original, the Distributor Doctor does excellent rebuilds (I have one on my 1030cc Minor) and will advise on ignition curves to suit your spec of engine. None of these options are particularly cheap though!

[philthehill]

Luminition is the way to go if you want reliable electronic ignition.
I have had the Performance Optronic system on my Minor for several years and it is totally reliable and can be changed back to points easily and quickly.

http://autocar-electrical.co.uk/lumenition

[edd_barker]

Thanks for the advice all.

My vac advance is broken, so I suppose I could try and replace that part with a modern one. I don't really want to spend £100+ on a posh new one!

Does anyone have any experience with the minispares ones?

http://www.minispares.com/product/classic/BAU1962.aspx

They are cheap, but my experience so far with minispares branded parts is that they are of excellent quality. I may give them a call.

Thanks,

Edd

[don58van]

The cheap electronic ignition distributors on the market are in my opinion not the way to go. The distributor caps are absolute rubbish. I have replaced two of them in the last year.

Declan (or others with experience with these)
Do the electronic 45Ds we are discussing here have the same cap as the genuine Lucas 45Ds? I would want to replace with a quality cap based on your advice.

Regards
Don

[Declan_Burns]

Don,
The cheapy caps supplied have a problem with a brush that wears prematurely. It appears to be too soft and doesn't seat correctly. The last such cap I removed, what was left of the brush and the spring, jumped out and I am still looking for it.
I contacted Martin Jay, the "Distributor Doctor", about this matter as he was repairing an original 25D for me at the time and he recommends the genuine Lucas cap you are referring to. He also has an improved version that he sells with brass inserts. He says it is a better fit than the Lucas which he quotes as always being loose. I had however already bought a distributor cap made by "FACET" and it appears to be top quality but whether it holds out only time will tell.

Regards
Declan

[edd_barker]

Just to revive...

If I buy an electronic distributor (no points), when setting static timing do I use a 12v bulb tester to know when contacts are open/closed? And then set the timing by ear as per usual?

I'm going to try one of the minispares modern distributors that they recurve themselves for modern fuels. I have found the rest of their own-brand parts to be excellent quality. I will report back!

Thanks,

Edd