Ignition coil overheating

[arcturus]

So, just to re cap. If dwell angle too high,points gap needs increasing to allow coil to deliver all it's energy?

[arcturus]

Another thought. On a twin contact breaker dizy how is dwell measured.Is it off each points set or an aggregate of the two. Do the points operate simultaneously or one set for three cylinders and another for the other three ? Can't quite get my head around this.

[pookie]

Originally Posted by arcturus

Another thought. On a twin contact breaker dizy how is dwell measured.Is it off each points set or an aggregate of the two. Do the points operate simultaneously or one set for three cylinders and another for the other three ? Can't quite get my head around this.

On the PRV engines one set of points fired 3cylinders and the other the remainder. One set of points was set inside the distributor, either with feeler gauges or if a dwell meter was used a piece of cardboard between the OTHER set allowed the first set to be gapped. At this stage ,the second set of points which was adjusted from outside of the distributor is roughly set.

Replace the distributor cap and with a strobe light set the ignition timing using no 1 cylinder. Then take the strobe lamp pick up and put it on cylinder5 start the engine and using the external point adjuster adjust the points until the ignition timing is the same as on the first set of points.

Points are now totally synchronised giving the same firing point for all 6 cylinders. I do hope this makes sense to you.

Salut!

Pookie

[mocambique-amazone]

Originally Posted by arcturus

For six cylinder should be around 30*

not on this kind of distributor George!!!!

If I write 42° I'm shure 42°; maybe strange to you.

I have this machine
https://i64.servimg.com/u/f64/12/04/23/30/img_0223.jpg
5 times and do work a lot on this kind of distributors. Only with this machine the job is very well done.
Regards, Kay

[arcturus]

you are correct. I did some more research and came up with the same number. Not my car but there is no such thing as wasted learning.

[arcturus]

Originally Posted by mocambique-amazone

not on this kind of distributor George!!!!

If I write 42° I'm shure 42°; maybe strange to you.

I have this machine
https://i64.servimg.com/u/f64/12/04/23/30/img_0223.jpg
5 times and do work a lot on this kind of distributors. Only with this machine the job is very well done.
Regards, Kay

i will have to send the dizy to "a small village North of Germany"

[arcturus]

Originally Posted by Derek UK

The Bentley uses a basic 3 ohm coil with internal ballast. If a 1.5ohm coil is fitted without an outside resistor it will run very hot and die pretty quick. If you have a spare for the 144 perhaps let him try that. Might need to adapt the pos and neg tabs and maybe the main coil wire fitting if his is currently a screw on type. No big deal though.

Why would a 144 coil possibly work. Does it have an internal ballast. problem still not solved. latest, the car will start but after a very short time coil heats up and starts to miss fire.

to me
Hi me again
I have found that 456 plug are the prob. so something is stopping the

the spark on those plugs. ( today started as i said all 6 running strong then 456 switch
off) any ideas?
I have told him to try fitting external ballast but he is convinced something else is causing problem. Some people won't be helped!

[mocambique-amazone]

Why the hell he trys Autolite 456?? If I remember right they are totally wrong.
Wrong heat range
wrong thread length


ohoh

still the prob with the over heating coil.


I would try Champion RN6YC and no Autolite

Maybe on this engine they used two different kind of plug threads : 14mm and 19mm long. He should get in contact with the bentley drivers. Or buy a good crystal ball of a visionary or should read in cold coffee.


good luck, Kay

[Derek UK]

I think he means cylinders 4, 5, 6. If the Bentley coil is spec'd at 3 ohm the 144 one will also work as that is 3 ohm. If the Bentley coil measures 1.5 ohm it needs an external ballast. Some early cars, all makes, used a circuit that switched out the ballast resistor when the starter was being used to give a fatter spark. It would then switch back to 3 ohm for normal running. Check that this car has this sort of system. That doesn't address your 456 problem. Bentley 6 cylinder firing order is probably 1-5-3-6-2-4. Check that.

[arcturus]

Thank's Derek, passed on the info. I suspect that the malfunctioning coil is burning out his plugs.
This has been quite a learning experience for me. well worth my time.