Ignition amplifier

[RobD]

Having done some very basic research into aftermarket ignitions I haven't found anything which tickles my fancy and have decided to stick with points. An ignition amplifier seems as if it it could be a worthwhile mod and I wondered if anybody had any experience, good ,bad or otherwise with such a system...


This is the kind of thing I'm talking about;

http://www.ebay.co.uk/itm/201450279206?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D201450279206%26_rdc%3D1

[lancialulu]

I did run a Sparkrite2000 on a 1300 very nicely. You could switch back to normal ignition and feel some difference (but not much). I sold the car with it as a period enhancement.

[Parisien]

Well maintained standard ignition will do just fine

P

[fay66]

Having done some very basic research into aftermarket ignitions I haven't found anything which tickles my fancy and have decided to stick with points. An ignition amplifier seems as if it it could be a worthwhile mod and I wondered if anybody had any experience, good ,bad or otherwise with such a system...


This is the kind of thing I'm talking about;

http://www.ebay.co.uk/itm/201450279206?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D201450279206%26_rdc%3D1

I have a very simple system that was made by Bob Seaney from a kit bought from Maplins, it's been fitted for about 8 years and works a treat.
You do need a new coil and do away with the old coil and ballast resistor.
If the box it's in looks familiar it's because it's a butter substitute container

Brian
8227

[peteracs]

Well maintained standard ignition will do just fine

P

Hi Frank

For sure, however do like the idea of the points acting as a trigger, rather than the full switch and having to be concerned about if/when they start to burn due to the back emf caused by the coil which eventually has an impact on timing etc.

Peter

[RobD]

Well maintained standard ignition will do just fine

P

Agreed P, but an amplifier arrangement can prevent the premature degradation of the points and maintain a more accurate setting for longer.

[Parisien]

Ok, but if car not doing a huge mileage, out in decent weather the degradation is much less relevant to majority?

P

[peteracs]

Ok, but if car not doing a huge mileage, out in decent weather the degradation is much less relevant to majority?

P

Hi Frank

That is for sure, on low mileage cars with regular checking, will most likely have little benefit, so the added complication would most likely not be worth it I guess. Also keeps the engine looks as original, though I guess it would not be too difficult to squirrel away.

Peter

[fay66]

Ok, but if car not doing a huge mileage, out in decent weather the degradation is much less relevant to majority?

P

Hi Frank

That is for sure, on low mileage cars with regular checking, will most likely have little benefit, so the added complication would most likely not be worth it I guess. Also keeps the engine looks as original, though I guess it would not be too difficult to squirrel away.

Peter

No scientific prooof but subjectively "Fay" seems to run better and ticks over much nicer, and I don't have to do regular point resetting, I think having a straight coil system as opposed to the ballast resistor and coil set up is a better solution.

Brian
8227

[lancialulu]

Ok, but if car not doing a huge mileage, out in decent weather the degradation is much less relevant to majority?

P

Hi Frank

That is for sure, on low mileage cars with regular checking, will most likely have little benefit, so the added complication would most likely not be worth it I guess. Also keeps the engine looks as original, though I guess it would not be too difficult to squirrel away.

Peter

when squirreling away remember that they need a good earth and means of getting the heat away from the power transistors....

[RobD]

I must say, Brian's amplifier installation looks Utterly Butterly to me...

[fay66]

I must say, Brian's amplifier installation looks Utterly Butterly to me...

Ouch !! it's amazing though the number of people who seem to recognise it from somewhere, but can't quite put their finger on it.
Obviously too slippery.

Brian
8227

[peteracs]

Hi All

I did a quick search on transistor ignition and came up with this writeup, which apart from the circuit details (you can skip that if not into electronics), has an interesting set of comments about the setup and longevity of the points setup..

https://www.cs.berkeley.edu/~wkahan/TransIgn.pdf

Peter

[DavidLaver]

A couple of quotes from the PDF document:

"The circuit is designed to relieve the breaker points of electric erosion caused by
heavy current, thereby rendering point adjustment unnecessary after the first 5000 mi. until over
50,000 mi., so that ignition performance does not degrade below its optimum as time passes. I
used this circuit for five years, 1969-73, in a car driven across the continent three times in all
weather, freezing winters, baking summers, and a flood. Only Capacitive Discharge is better."

"Since point erosion is almost eliminated you may safely increase point dwell by up to 20% and
advance spark timing by 2˚ to retard rubbing-block wear and improve high-speed performance.
And widening spark-plug gaps by about 20% will improve low-speed running and starting."

"The advantage over then Standard ignition of this Transistorized ignition is only that the current
through the points is reduced well below what would erode them by sparks’ action. The points do
get beaten down by banging against each other, and the breaker arm’s fiber rubbing block gets
worn down by friction with the cam in the distributor, but these effects slow down and become
negligible after about 5000 miles provided the cam is greased adequately but not excessively.
The points get work-hardened by beating against each other; the fiber block becomes smoothed
and slippery, saturated with grease. After 5000 miles I did adjust the ignition for longer dwell
and advanced spark timimg; these remained practically unchanged for the next 75000 miles
until, with the change to Capacitive Discharge ignition, I advanced spark timing a little more.
That stayed put for the next 40000 miles, after which the cars were retired because I could not
get exact replacements for the brakes’ master cylinders. Otherwise I would still be driving them."

[RobD]

It's very interesting stuff. One thing which puzzles me is how do you physically adjust the dwell?