I am in the process of installing a new timing pointer on my 1969 E-Type 4.2 engine. The old one was lost at some point before I owned the car. I have been timing the car by ear - advancing the timing as far as I dared and listening for pinging. I have decided to see how far off I am and install a pointer. The new item is slotted for adjustment, so I need to set it at exactly TDC for it to be accurate.

Any suggestions as to finding TDC with any precise accuracy?

Thanks,
Josh
1969 E-Type OTS,
1997 XK-8 Convertable.

Submitted by SE21-38504 on Mon, 06/04/2012 - 15:47

Edited on 2012-06-04 16:01:21

Josh, I also had a missing timing pointer on my 1969 E-type FHC when I bought it, so I used the same technique that I used to use on my old Yamaha motorcycle:

1. Note where the #1 spark plug (plug closest to firewall) wire goes into the distributor cap. Apply tape to the side of the distributor housing and make a mark on the tape, or dab white paint to the housing. Now, remove and set aside the distributor cap. Turn the ignition advance micro adjuster to app. middle position (maximum about 10mm in-out).

2. Set handbrake. Put gearbox in neutral position. Jog engine with starter until the rotor points to #1 spark plug position.

3. Remove #1 spark plug (nearest to firewall) and insert the end of an extended mirometer into the spark plug hole until it touches the top of the piston. A piece of straightened coat hanger wire or long screw driver will do in a pinch. (A dial indicator is best if you can borrow one, but not many people have one lying around unless you had an old motorcycle.)

4. Put gearbox in 4th gear, release handbrake, and rock car ...
- or -
Turn engine over with a 34mm socket and long handle over front crank pulley nut ...
until the micrometere or wire is at its maximum length out of the hole. That is TDC "top-dead-center"

5. Now attach your pointer to the bottom of the front of oil pan to point at zero degrees on the pulley. Rub some white paint into the markings on the pulley if they are had to see.

6. Reattach the distributor cap. Connect timing light to #1 plug. Connect dwell meter to coil - terminal (yellow wire) and ground.

7. Loosen distributor pinch clamp bolt.

8. Rotate distributor clockwise (viewed from above) so that the rotor advances in the direction which the engine runs (counter clockwise viewed from above).

9. Stop rotation just as timing light flashes and dwell meter needle jumps.

10. Tighten pinch clamp bolt just enough to prevent the distributor from turning.

11. Warm the engine and idle at 1000 rpm. Final adjust timing with the micro adjuster so that the timing light flashes on the upper timing alignment mark on the front crankshaft pulley (10?? BTDC @ 1000 rpm).

By the way, I fashioned a new pointer from flat stock and attached at the front cover using the idler pulley mount bolts. Then I filed marks into the front pulley to correspond to 5?? BTDC (timing @ static) and 10?? BTDC (timing @ 1000 rpm). Ignore the XR700 in the diagram ... I have a Crane electronic ignition module.

Now I can see the timing marks from above the engine when turning the distributor rather than having someone crawl under the front of the car. Why didn't Jaguar do it that way to begin with!

Good luck!
Bill Unger, wm.c.ungeratgmail.com
1969 E-type, 1997 XK8, 2007 XKR, 1987 Alfa Romeo Spider Veloce

Submitted by Anonymous (not verified) on Sun, 12/17/2017 - 17:25

Just bought a 1969 Fixed Head Coupe that was not running well.
Cleared a number of problems and was running but made poor power.
Timing was the answer to unlocking the power.
Loved Bill's solution with pointer where you could see it without ramps and an assistant.
May I add that you can use the original pulley marks with your new pointer if you position it and time from cylinder #3.
You are just measuring 120 degrees later with a cylinder that fires 120 degrees later.
Worked great for me.
Andy

Submitted by SE98-32482CJ on Sun, 06/03/2012 - 19:26

Josiah you said precise--Dave's system works but to be "precise" use a dial indicator rather than a rod--make sure your harmonic ballancer is in good shape and has not slipped due to age.

Submitted by woebegone@mind… on Sun, 06/03/2012 - 17:42

There are tools for it, degree wheels.....but, you need to use a fixed probe in place of the rear plug that is NARROW and will NOT impact either valve.....roll by hand until you contact it, mark the pulley....roll the other way all the way around, mark the pulled when you contact it, TDC is exactly between the marks.
I have never done it on a Jag, I'd have to look for valve interference with the plug hole.
Look and see if the valves cover the hole too far.
We used to take an old plug, knock all the porcelain out, weld a rod into it, try it, grind off excess length until we were fairly close on the marks.
1/4" rod is all you need.
Dave