Amazon: Electronic Ignition

[Bracpan]

Originally Posted by Burdekin

Also worth asking Rob about the manifolds and header etc. If going for SUs you can get the separate SU intake manifold and then get the good flowing separate exhaust manifold rather than a header.

https://www.sw-em.com/manifolding_notes.htm

That's good info thanks, I have the SU's and the alloy inlet manifold ready and was thinking of using the twin outlet cast exhaust manifold as well, i see they are being sold again by Brookhouse but ill see if i can get a good second hand one for a better price.

The list of the heads is the one i sent in a little while ago, I have a spare the low compression head by the look of the measurements so i will prepare that one ready I'm not sure if ill fit bigger inlets as yet but i also have a list of all the parts needed... i will need new valves anyway so might go down that route... thanks for the 123 info i will get it from Amazon as they do seem to have the correct maps for unleaded..plus as you said i hope to get some advice from them. I have been buying parts from both Brookhouse and Amazon Cars since I've owned the Volvo...both been very helpful.

As i said my Amazon is only a cruiser a have a competition car for out and out speed

[Bracpan]

Originally Posted by Derek UK

Don't use a B20 head on a B18. Yes it will run smoothly but that will be down to low compression unless the B20 head is skimmed quite a bit. B20 compressions are adjusted by head gasket thickness whereas the B18 CR is done by head height. There are different gaskets but Volvo mostly just used one. B20 on B18 gives a mismatch in the larger combustion chamber size on a smaller B18 bore. You then have to pick either a B18 or 20 gasket and neither will match the head to block joint around the bore. Any spec that ends up at 9.0 to 9.5 CR will much prefer best pump fuel. The engine feels noticeably smoother and a bit more lively. Anything over that i.e. the 10.1 engines needs the best, they were designed for 100 octane. B18a and B20a with standard compression can get by on 95 but better on 97, Twin carbs and higher CR best on Premium 99 IMO even at the extra cost.

Much appreciated info
As i dont do that many miles a year in the Amazon i dont mind running premium fuel..many thanks

[Bracpan]

I have searched high and low and cant find my timing gun....
Can anybody recommend a good one and is it worth getting one that can set the timing on digitally and see the engine speeds ?

[Ron Kwas]

BP;

...you don't really need one! Just follow my steps for Static Timing, and you'll be within a degree or two, and check function of your Ign Sys (except for Centrifugal Advance) at the same time!

See: https://www.sw-em.com/Volvo%20Igniti...tatic%20Timing

Cheers

[HRA]

I went for PowerSpark for my B20A Amazon. I've had it for few years now and it's been totally reliable (touches wood quickly!) It didn't cost the earth and it has saved me the frustration I've previously had with poor-quality condensers on other cars.

The only downside is that if you have a rev-counter then you probably need to budget for a RVI-RVC conversion board to make it work again. I got one from Spiyda that does the trick. It was easy enough to install and calibration was straightforward.

[Bracpan]

It looks like its cheaper to get a 123 Dizzy from the manufacture in Holland

[Bracpan]

This amazon is driving me around the bend...
I got a timing gun, set it at the correct settings in the book ( it was slightly out)
Drove it today and the damn thing is slightly worse.
I had the exact same problem last year it runs ok until you hit a long hill, you would swear its not getting enough fuel, but checked all that and even fitted a new fuel tank to get rid of the crud in the old one.. problem still there.
I then changed the points, condenser, plugs etc and it was fine...
But a few weeks ago without doing anything too it the problem returned..
On a long hill it just goes flat and missing....again you swear it was fuel..
But it only went when I changed the ignition parts.... i think its something do do with sitting around for so long during covid, but i did start it every week and warmed it up fully....
Its cant be points and plugs again as its not done many miles since!!!
Something is breaking down under load ? I've had coils go before but usually they just stop....im really getting pi***d off with it now..

[Burdekin]

What carb or carbs have you got?

If fitting the 123 dizzy ideally you should also fit the blue Bosch coil, I’d do that before messing with the carb unless you have a Stromberg?

[Bracpan]

Its a Zenith carb I know about SU's but know B all about Zenith...
But i still believe its to do with the ignition ...

[142 Guy]

Have you checked the operation of the advance mechanism with your timing light? Run the engine from idle up to about 2500 - 3000 RPM (wherever maximum advance occurs) and check for smooth and correct advance with your timing. Repeat 2 -3 times to check for consistency.

If the advance mechanism works as it should, carefully examine the spark plugs, coil and spark plug high voltage wires, the rotor on the distributor, the distributor cap wire connections and the inside of the distributor cap and the tower on the high voltage terminal of the coil. What you are looking for are signs of carbon tracking which can lead to flashover and ignition misfire. On the wires you will have to pull back the protective rubber boots to expose the insulated end of the wire to determine if there is any surface tracking on the wire. Misfires due to carbon tracking can be engine load sensitive and can be sensitive to atmospheric conditions. Tracking may cause misfires in cool / damp conditions and then vanish under hot / dry conditions.

If the timing is good and there are no signs of flashovers the next time you start to suffer from the problem, remove the plugs and have a look at the porcelain surrounding the center electrode. Does the color indicate that they are running on the lean side? If so, you might be getting lean misfire and perhaps your problem really is a fuel problem, not an ignition problem.