Wanted - A great Big Spark

[RogerH]

Hi Folks,

having sorted the stale fuel on the TR4 and got the gap sorted on the contact breakers the engine although now starting straight away was not running smoothly.

Out of curiosity I removed the HT coil ( a black thing that came with the car with the  belittling title of 'standard coil' and fitted  a (possibly) Lucas Gold sports coil.

This brought about an immediate improvement in the running. The revs increased, probably all 4 plugs were now firing.

As these 'sports' coils do not get the best press what would be an improvement. 

On the 4A I have a flame thrower coil from the Dizzy Doc. This works fine but I do not know how well it actually works. Is there better than a 'flame thrower' ?

 

Roger

[jerrytr5]

Have you tried a Romain Grosjean?

[RogerH]

That was some spark.  

 

 

[Ian Vincent]

Look for a Bosch Blue Coil, or a red one but then you need a ballast resistor.  They do turn up occasionally on Ebay.  I reckon they will give you as much spark as a Flamethrower.

Rgds Ian

Here is a link to what appears to be a genuine Made in Germany one.

Bosch Blue Coil

 

Edited November 30, 2020 by Ian Vincent

[RogerH]

15 minutes ago, Ian Vincent said:

Look for a Bosch Blue Coil, or a red one but then you need a ballast resistor.  They do turn up occasionally on Ebay.  I reckon they will give you as much spark as a Flamethrower.

Rgds Ian

Here is a link to what appears to be a genuine Made in Germany one.

Bosch Blue Coil

 

Thanks Ian,

I have gone with that.

If you see a vivid glow in the east at the week-end you will know it has worked.

 

Roger

[trchris]

Hi roger

Euro car parts do the Bosch coil

part number 413110037 with there discount doesn't seem a bad price either

Chris  

[RogerH]

Thanks Chris,

I'll see how the Beru goes but I will keep yours in mind.

 

Roger

[DaveN]

What’s the thoughts on the Accuspark iteration of coil?

[Nigel Triumph]

7 minutes ago, DaveN said:

What’s the thoughts on the Accuspark iteration of coil?

I have an Accuspark coil on my Scimitar GTE. The coil has worked fine for several years but I couldn't say if it's better or worse than any other.

Nigel

[Andy Moltu]

My original Lucas Gold on the 6 failed after 25 years. I had a spare Lucas Gold in the boot (just as well as we were on the Ile De Reye meandering down to Pamplona) however this seemed smaller in diameter then the previous so replaced it with a Bosch Blue (so far so good).

I have had an Accuspark on the Stag for 5 years since I ditched the ballast resistor.

Given that these are all essentially 3 Ohm resistance they, in theory draw 4 Amps and the power is 48 Watts.  Whilst in theory you can alter the numbers of coils on the LT side relative to the HT side to produce a higher voltage to generate the spark that spark should have the same total wattage. However cranking up the voltage beyond a certain point may lead to the spark exposing the limtations of other parts of the ignition system (cap, rotor arm and leads)

You would hope that the non cheapo ones use better quality components for longevity and hopefully to allow relatively more of the energy to the spark rather than generating heat.  But beyond a certain point are some of the claims hype over reality to justify a higher price.

[RobH]

18 minutes ago, Andy Moltu said:

However cranking up the voltage beyond a certain point may lead to the spark exposing the limtations of other parts of the ignition system (cap, rotor arm and leads)

In practice you only reach as many volts as it needs to break down the spark plug gap. The ultimate voltage that the coil can generate doesn't affect that.  Provided the gap isn't set stupidly wide the system should cope whatever coil is used - the rated 30-40kV is never reached as the gap probably requires less than 20kV at most. 

The problem with the Kettering system is at high revs, when the 'dwell' time, during which the points are closed and the coil is charged with energy, becomes short.  The voltage output from the coil starts to drop off as the revs increase so that with a normal coil the point is reached at very high revs where there may not be enough voltage to strike the spark reliably. The 'sports' coil starts off with more voltage available so even when the output sags there is still enough to do the job at high revs.  

 

 

. 

[stuart]

1 minute ago, RobH said:

In practice you only reach as many volts as it needs to break down the spark plug gap. The ultimate voltage that the coil can generate doesn't affect that.  Provided the gap isn't set stupidly wide the system should cope whatever coil is used - the rated 30-40kV is never reached as the gap probably requires less than 20kV at most. 

The problem with the Kettering system is at high revs, when the 'dwell' time, during which the points are closed and the coil is charged with energy, becomes short.  The voltage output from the coil starts to drop off as the revs increase so that with a normal coil the point is reached at very high revs where there may not be enough voltage to strike the spark reliably. The 'sports' coil starts off with more voltage available so even when the output sags there is still enough to do the job at high revs.  

 

 

. 

Magneto?

Stuart.

[RobH]

Ah yes Stuart -  as you say. The output of a magneto increases with revs, so it doesn't have the same problem as a Kettering coil within reasonable operating speeds.  More complicated though and a bit beyond my experience except for the simple one on my lawn-mower. Have you used one?

[stuart]

5 hours ago, RobH said:

Ah yes Stuart -  as you say. The output of a magneto increases with revs, so it doesn't have the same problem as a Kettering coil within reasonable operating speeds.  More complicated though and a bit beyond my experience except for the simple one on my lawn-mower. Have you used one?

Only on cars that had them as standard, they pack a hell of a wallop if your not careful.I do seem to remember someone toying with the idea of using one on a TR but that was a long time ago.

Edit. Found it https://www.tr-register.co.uk/forums/index.php?/topic/62937-lucas-magneto-on-a-tr2ever-an-option/

Stuart.

[BlueTR3A-5EKT]

36 minutes ago, stuart said:

Only on cars that had them as standard, they pack a hell of a wallop if your not careful.I do seem to remember someone toying with the idea of using one on a TR but that was a long time ago.

Edit. Found it https://www.tr-register.co.uk/forums/index.php?/topic/62937-lucas-magneto-on-a-tr2ever-an-option/

Stuart.

You beat me to it Stuart

 

 

[RogerH]

On 11/30/2020 at 5:52 PM, Ian Vincent said:

Look for a Bosch Blue Coil, or a red one but then you need a ballast resistor.  They do turn up occasionally on Ebay.  I reckon they will give you as much spark as a Flamethrower.

Rgds Ian

Here is a link to what appears to be a genuine Made in Germany one.

Bosch Blue Coil

 

Hi Ian,

your link took me to a Beru coil. I ordered that and it arrived today.  It looks unassuningly nice.

I'll pop it on  the 'Blue Racer' next time I'm in the off-site garage (tomorrow)

 

Roger

[Ian Vincent]

So did your new coil do the trick Roger?

Rgds Ian

[BlueTR3A-5EKT]

On 12/3/2020 at 11:42 AM, RogerH said:

Hi Ian,

your link took me to a Beru coil. I ordered that and it arrived today.  It looks unassuningly nice.

I'll pop it on  the 'Blue Racer' next time I'm in the off-site garage (tomorrow)

 

Roger

Project here for you Roger.

https://www.mahle-powertrain.com/en/experience/mahle-jet-ignition/

 

 

Peter W

Edited December 17, 2020 by BlueTR3A-5EKT
Redacted

[RogerH]

2 hours ago, Ian Vincent said:

So did your new coil do the trick Roger?

Rgds Ian

Hi Ian,

I've been distracted and haven't made it to the hibernation den for the TR4. I'll try and sort it over the week-end.

1 hour ago, BlueTR3A-5EKT said:

Project here for you Roger.

https://www.mahle-powertrain.com/en/experience/mahle-jet-ignition/

 

 

Peter W

Hi Pete,

not exactly plug and play.

 

Roger