Engine timing marks?

[PPV]

I have a 1961 3.8 Mk2 and have recently installed Powerspark electronic ignition. It certainly sharpened up starting but I was conscious that I had never checked the timing since I had bought the car about 15 years ago.
The engine number is LB4894-8. I have had a look on the BB but could not find an answer which addresses my issue.
The problem is that I cannot find any graduated timing marks on my front pulley except for 2 lines about 10 degrees apart on the side face of the flange. I have a pointer attached to the engine at the bottom and I do not have any marks at all on the flywheel or the access port at the bottom of the bellhousing which I understood is an alternative position for markings.
When I use my timing light the two marks are miles away from the pointer and at about 500 rpm it is 'timed' at about 15 degrees after TDC. I checked the TDC position with getting no 1 cylinder at TDC and it looks like one of the marks could be the right one. However, if I use that mark and assume that the other one is 10 BTDC the engine runs rough. If I increase the revs then the assumed TDC mark does move closer to the pointer position and at about 3000rpm it shows 20 BTDC.
I had understood the car should have static timing of about 10ish BTDC (500rpm before mechancical advance has chance to operate?) and at about 3000rpm should have about 38 BTDC showing (vacuum pipe blanked off).
Now could anyone advise if the marks I described are in fact the TDC and 10BTDC and secondly if it should be Ok to run it as set?
I have tried adjusting the vernier and if I retard it more than originally set it spits back through the carbs and if I advance it then it seems to run roughly as though one cylinder is not firing all the time. ( I have tried loosening the distributor but at present cannot get it to move!).
I have checked the distributor and there is no play in the shaft and the car has always started well but has not run on the road as smoothly as I would have expected (slight roughness like a cylinder does not always fire). This was the case with points installed also. It has new spark plugs, distributor cap, rotor arm and leads as well as the electronic ignition. All these have made no noticeable difference.

Many thanks,
Paul

[oldtimer]

Try polishing the front face of the damper flywheel with a piece of fine wet and dry paper dipped in white spirit. The engraving of the timing marks can be quite faint.

[Martec]

Hi Paul,

Our MkII is January 1961 and an LA engine, so I doubt there will be little difference between them. Firstly the front damper is on a taper, this taper is keyed to the crankshaft, but the damper isn't keyed to the taper and so can be any orientation, as this has the timing marks then it is essential to find top dead centre (TDC) first. There a number of ways but they are basically the same.

Disconnect the battery so it can't try and start.

First take the plug out from the front cylinder and turn the engine until the you can see the piston is at the top (no need to be precise yet) using either a light, or a screw driver down the hole, but the handle must be bigger than the hole so it won't fall into the cylinder, turn the engine with the big nut in the centre of the damper whilst lifting the screw driver (it is at the side of the piston so can jam if you are not careful).

Using a thin strip of paper about 8" long stick this to the edge of the damper so that your pointer on the sump is about in the centre of it.

Now you need some way of restricting the piston or measuring its height,
1) find an old spark plug, smash the centre out of it and weld a bolt passing through it so it sticks down about 1.5". turn the crank away from TDC and screw the modified plug into the hole and turn the crank back until the piston hits the bolt (lightly). Mark the paper strip where the pointer on the sump is. Carefully turn the engine back all the way round ( probably close to 270 degrees until the piston again hits the bolt. Again mark the strip of paper which should be at the other end of of the strip. Carefully measure the distance between the two marks, halve it and mark this into the paper strip then permanently mark the damper (the damper is now 50 years old and made of two steel pieces held together with old rubber so if you are going to punch or chisel it do it on the edge).

2) or you can use a Dial test indicator (if you have one) a long nail (6") punch it through a small socket to cup the end and weld a washer to the top so it can't fall into the cylinder, put this into the centre of the plug hole and lightly pop this so the point is located into the piston (sloping side of the piston crown) using the DTI in the cup of the nail you can move the crank back and forwards to roughly zero the scale, then turn the engine one way until the gauge shows a good deflection say 90 thou, mark the paper strip, move the crank back and go over zero to 90 thou on the other side and again mark the paper. Measure, halve and mark paper and damper.

You can measure the circumferance of the damper, or from the diameter calculate it and divide it by 36 for 10 degrees of crank rotation and mark up the damper.

So now you have TDC and 10 degrees of rotation, easy enough to mark up other degrees of ADVANCE.

The timing figure is for static advance and your strobe is being acted upon by the vacuum advance so this needs to be disconnected at least.

Of the two methods I prefer 2 as I used that, it is more accurate and there is less turning of the engine backwards, but it is up to you.

The distrubutor is held in place by a bolt through a plate into the block and a pinch bolt to clamp the distributor, both need to be slack to turn it.

I hope that isn't too daunting, best wishes

Brian

[PPV]

Thanks for the replies. I have cleaned the face of the damper but there are no marks whatsoever on its face only the ones on the edge which are just two fine lines.
I found TDC by using a vernier gauge inserted through the plug hole and did that several times checking the position of the marks on the damper when TDC reached which gave the results I identified. I did not use the paper trick so will try that to give me the 'difference' between two TDC positions as suggested. I find it difficult to turn the engine (all plugs out) and use the solenoid to roughly get piston near TDC then spanner on crankshaft, but backwards and forwards is a bit of a fiddle. Also my good lady loses patience looking at the gauge stuck down the plug hole (not very mechanically minded) whilst I do it!
I did not realise you have to release a location bolt as well as the clamp to move the distributor as there is no mention in myservice manual. It just says to slacken the pinch bolt and you can withdraw the distributor but looking at the manual on the exploded view on page 15 I can see a slot in the clamping plate. I will try to locate the bolt through the plate next time I have a fiddle, I just need smaller hands and longer arms!
I checked the timing with the vacuum advance disconnected.
I will run through it again with the suggestions and see what I find.
Regards and once again thanks for help.
Paul