Setting points

[oxf2]

Showing below is a pic of what's under the distributor cap. Since I'm checking the points for 15 thou, I've got the spur on the heel of the cam. But which screw to turn, screw 1 or screw 2, as shown in the pic below?

[RobH]

The adjustment isn't just to turn either. They are there to clamp the points plate to the base-plate.  If you look closely you can see that the hole under screw #1 is slotted, which allows the C -shaped plate carrying the fixed points contact to swivel on the base-plate.

Slacken both screws slightly and then swivel the plate until the points gap is correct, then tighten both securely. 

[billy l]

I would do something about the bare red with yellow tracer wire before it shorts out.  Cheers, Bill.

[RobH]

Good point Bill. That has obviously been 'repaired' at some point as the wire shouldn't be a solid-core one anyway, it should be flexible.  

(Although that dizzy doesn't seem to have vacuum advance, the wire does need to be moved sometimes to adjust the gap and replace the points, so a solid-core wire will eventually fracture from the bending) 

[billy l]

6 minutes ago, RobH said:

Good point Bill. That has obviously been 'repaired' at some point as the wire shouldn't be a solid-core one anyway, it should be flexible.  

(Although that dizzy doesn't seem to have vacuum advance, the wire does need to be moved sometimes to adjust the gap and replace the points, so a solid-core wire will eventually fracture from the bending) 

Rob, Isn't that the vacuum advance at the bottom of the pic?

[RobH]

I thought that might be just a manual advance-retard screw adjustment but looking again it might be vac as you say.  If it is vacuum A-R then that wire would soon break. 

Edited December 6, 2022 by RobH

[DesNoble]

The best way to set points is by using a dwell meter. It's cheap and easy to use. The easiest way is to remove the distributor cap and rotor arm, set the points roughly with a feeler gauge then connect  12v across the points with the dwell meter attached. For a 4 cylinder engine it's 60 deg. so you just motor the engine over and set the timing while you are doing that. Job done.

[oxf2]

Thank you all for your help and suggestions. Points are fine now, though I have yet to replace that single core wire, which I will do asap

[John McCormack]

I've never seen this type of distributor on a TR. Most of my experience is TR2s and 3s, is this on a late 3A.

[Lebro]

Looks like a normal 25D4 to me ?

Bob

[BlueTR3A-5EKT]

It’s a DM2 distributor on a TR2.  With the awfully expensive 2 screw points.   Same points as Daimler Dart uses.  The vacuum unit connects with a pin and sprung ‘R’ clip.   The parallel hole the pin goes into on the base plate wears oval and the timing scatter is quite noticeable.   The bob weights have inset brass pivot bushes that wear oval too.   Works fine when new or fully reconditioned.

[Phil Read]

I fit an electronic ignition kit, fit and forget. The car starts much better and runs better at low revs.

[BlueTR3A-5EKT]

16 minutes ago, Phil Read said:

I fit an electronic ignition kit, fit and forget. The car starts much better and runs better at low revs.

+1

[DesNoble]

I had an electronic kit but had terrible problems with timing and engine cutting out. Finally having checked everything from cam timing to carb jet rebuild I replaced the electronic ignition with a set of good points - bingo the car runs beautifully and the timing is spot on the curve.

[Lebro]

43 minutes ago, Phil Read said:

I fit an electronic ignition kit, fit and forget. The car starts much better and runs better at low revs.

+1 (Pertronix)

Bob  (must pay more attention to Dizzy types  )

[John McCormack]

16 hours ago, Lebro said:

Looks like a normal 25D4 to me ?

Bob

It was the points that threw me, I've not seen them with two set screws. All of mine have the one screw and slot to put a screwdriver in to adjust the gap.

I've also put electronic ignition in all the TRs except for the concours TR2, which runs points for originality. The TR3 has Pertronix and the TR6 and daily driver TR2 both have Lumenition. Both types seem to work reliably and efficiently.

Edited December 8, 2022 by John McCormack

[RAHTR4]

Hi,

You have a P.M.

Regards, Richard