Manually setting the timing?

[TheDampMan]

I have recently replaced my Opus ignition with the HE Conversion Kit curing the starting issues I had with the car, however because my car has no timing marks (no pointer or markings on the damper!) when replacing the distributor I marked the position of the old rotor arm and fitted the new distributor to the same position but have no idea if the engine is timed up correctly other than to say it starts and drives ok without pinking.

My next stage was going to be to slightly loosen the distributor bolts so I can advance/retard the timing and test drive each time to see if any improvements occur?

Any thoughts advice will be appreciated.

[42south]

Hi
Why don't you make a double stop measuring device from an old spark plug. Knock out the center, and braize a nut to the top then use an appropriate sized bolt through the nut. This simple device will allow you to accurately find TDC on the No1 cylinder, front right. Then you could either make up your own plate, or buy a marked one from SNG. Would also allow you to mark the Flywheel accurately.
The actual double stop method has been described on the forum several times, just search. Also YouTube is good for a demo as well.
The only proviso for the V12 is not to turn the engine backwards, you may break the tensioner.
I think the problem with trying to adjust the distributor and listening for pinking is that some detonation is inaudible.

[lowact]

Mark beat me to it. Bloody kiwi’s always out of bed too early. Same advice as was given 2 u earlier. Reiterating and expanding:
1. The way to set static timing without a timing mark is to first create a timing mark. Because you often need a timing mark. In the long run, reinstating a timing mark is far and away the smartest thing you could do. You cannot rely on ability to hear “pinking”. Also “pinking” is caused by a combination of factors. If you are fortunate enough to be able to hear damaging “pinking”, you do NOT adjust the static timing to eliminate this. You check the static timing to eliminate static timing as a possible cause …
2. Remove the timing pointer plate (with the angle markings, Jaguar part C34492) so that you can properly inspect the damper for timing marks. U will need to remove the oil filter to do this (don’t need to drain the sump). If you don’t have a timing plate buy one. Be careful of the SNGB offering, their illustration is wrong but would be useful if you followed Marek's earlier advice and set up a timing plate in a more accessible location.
3. Double check that you really don’t have a timing mark. This is a deep mark with a deeply engraved “1A”. It is impossible for this to be worn away by the timing pointer plate, the plate would be worn away first. Remove the spark plugs so that it is easier to turn the engine by hand. (Only ever rotate your engine forward, otherwise there is risk of damaging the timing chain tensioner. Forward is clockwise when viewed from the front of the car, CCW when facing forward.) Remove the distributor cap so u can see the HT rotor. Rotate the engine forward by hand (7/8” ring spanner) until the HT rotor is pointing at the LH headlight. Carefully check the accessible surface of the damper for timing marks, that may have become filled in with paint or crud. The engine turns twice for each turn of the distributor so turn the engine forward again until the HT rotor is pointing at the RH side door handle and check again for a timing mark.
4. If there is no timing mark you either buy a damper that has one or u create one on your existing damper to indicate when piston 1A (front piston RH side) is at TDC (top dead centre). In this position the big end is moving sideways so there is a lot of angular movement of the crankshaft with no discernible vertical movement of the piston, therefore it is almost impossible to accurately locate TDC using a dial gauge down the spark-plug hole. Instead you should use the “double stop method” as per Mark’s advice previously.
5. The “double stop method” requires u to build or borrow a special tool, that looks like this:
https://1drv.ms/u/s!AiSPBKa26IcchJwLwPQoACBeLra1vA
I.e. a spark plug with the ceramic bashed out of it, with an 8 mm dia. screw thread tapped down the centre for a 100 mm long bolt and a lock nut. Removing the ceramic from a spark-plug without distorting the metal is quite difficult. it is very important not to distort the steel plug as this would damage the threads of the spark-plug hole in yr aluminium head. Start with a plug that screws easily into the 1A spark-plug hole by hand. If yr plug deconstruction distorts it so much that it is not possible o install the plug by hand, chuck it and start again. When working on the spark plug, to avoid damage, don’t hold the plug directly in yr vice, support it in a spark-plug socket in the vice. Is a good idea to first cut/grind/file away the top edge of the metal (between the hex and the ceramic) this makes it easier to knock the ceramic out from the bottom. I didn’t do this, consequently it took me forever. Live and learn.
6. Rotate the engine forward until cylinder 1A is at TDC on it’s firing stroke, this will be when the HT rotor is pointing to the distributor cap terminal that supplies cylinder 1A. This should also be with the HT rotor pointing at the LH headlight.
7. Screw yr special tool firmly into the 1A spark-plug hole. Screw the bolt down until it hits the piston. Rotate the engine forward a tiny bit and screw the bolt down to the piston again, repeat until the bolt is almost (but not) fully screwed down. Lock the bolt firmly down onto the piston using the lock nut. Confirm that the bolt is preventing the engine from being rotated backwards, even a smidgin.
8. Reinstate the timing pointer plate or some other reference mark. Make an accurate mark on yr damper that is opposite yr reference mark. Rotate the engine forward by hand until the rising piston is stopped again by the bolt. Make another accurate mark on yr damper. 1A TDC is at the exact middle in between the two marks. Use hacksaw blade or thin file to cut a 1A timing mark at this location, highlight it with white paint, shout yourself a beer.

[42south]

Hi guys
Steve, I also fitted the SNG ignition upgrade, you’ll like it.
A couple of things with it, they recommend a very conservative static timing setting, 8dtdc I think.
When you figure out where TDC is you may wish to set 12 deg BTDC, which was the jaguar recommended setting.
The distributor fron SNG still has a retard vacuum module fitted, as per the original. This was only done to try and meet USA emissions regs at the time. It hurts performance and fuel consumption, best left disconnected, and blank off the inlet on the capsule, and the one underneath the left rear carb.
In the future you may wish to fit an advance capsule to the dizzy, there is plenty of info on the site, just search.
Regards

[TheDampMan]

Thank you both for your detailed replies, I think first I will double check for the mark on the damper and also order a new timing pointer plate.

[Bob.]

You may have found the damper "1A" timing mark by now but in case not this is what you are looking for. I think the 1 is hidden under the paint I put on a while ago but the A is clear enough.