1750 electronic ignition. Can anyone tell me if this unit is worth having

Started by berlinaman, January 21, 2010, 05:38:27 PM

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berlinaman

My 1970 1750 berlina has this unit fitted in the engine bay which I believe is an electronic ignition unit. It does not seem to be connected. Has anyone any experience with these units and if so would it be worth seeing if it works. If not what is the recommeded system to use. Someone suggested a unit from a late model alfetta. Is there other things that need changing if fitting one, and are they worth having?

MD

berlinaman,

As you know whenever you ask for an opinion, you will get some-not necessarily all swimming in the one stream. My overview is this.

There are two sides to the story.
1 Plugs and points are the simplest ignition sytems around. Everybody understands them. If you have an ignition breakdown almost all amatuer mechanics and certainly all qualified mechanics will know how to fix it. If they don't, they must have done their apprenticeship on steam engines. So simplicity and ease of service are its virtues.
It's drawbacks (for the sake of brevity) are a need for regular servicing and the possibility of spark issues at high rpms which are more in racing applications than road use.

2 Electronic ignition systems likewise have benefits and drawbacks. The first one will be the cost of doing a conversion and whether you will recover that in the car's residual lifetime. The second one is the breakdown issue. Less people will know how to fix it and when they do, it will be more costly.
On the upside, these systems produce a more consistent spark throughout the rev range and perform better at high revs than points  as there is no points bounce. If you dont live in the high rpm zone, it's a marginal gain.

If you decide you want to go electronic, there are basically three types . Optical ,magnetic and inductive pick ups and your distributor will need to be modified to do the job.

As for the one you got in the photo, it has probably seen better days and without a circuit for it, well it's good money after bad..

I hope that helps a little
Transaxle Alfas Haul More Arse.

Current Fleet
Alfetta GTV6 3.0
Alfetta GTV Twin Spark supercharged racer
75 1.8L supercharged racer

Past Fleet
Alfa GT 3.2V6
Alfetta GTV 2.0
Giulia Super 2.0
Berlina 2.0

GTV-074

I wouldn't keep any electronic device that looks as old as that.....

We all know the advances made in electronics over the last 20 years....

As mentioned above points/coil are a much easier option.

For example when I purchased my GTV years ago, it came fitted with a pirana electronic ignition / Mallory coil...... left me stranded away from home twice....not a third time tho as they both ended up in the hard waste collection!

I have never had an issue since after going back to points/coil.....

If you want to go down the electronic path.....I am sure there are better units available these days. Perhaps another thread on what units available may suite a 105.

I have a new Marelli electronic unit I purchased for my GTV about 25 years ago sitting on the shelf....been to scared to ever put it on!

Also the fact that its not an "Alfa" unit.....can't see the point of keeping it.....turf it out I say!

Cheers.
Speed costs money - how fast do you want to go?

berlinaman

Thanks guys,
I guess I will remove the old thing and stick with the points. Thanks a lot for your replies.
cheers
Tony

MD

Tony,

A further little tip. Marelli distributors are fine while they work and if you only have it serviced by authorised Alfa dealers as they will know how to set them up and keep them going that way. Regular mechanics prefer the more conventional Bosch units as they are much more orthodox. Either way, it pays to make sure it is not sloppy in the shaft, the condesor hasn't dried out and is of the correct value to minimise points pitting and the cap and rotor are not too worn at their contact points.  Please note that you may see 2 condensors around the dizzy. One is part of the ignition circuit and the other one is a noise suppressor for the radio. Also be sure the cap is clean inside to prevent arcing between adjacent contacts which is bad news.

If you run your engine at night in a dark location and lift the bonnet, you will see high tension arcing along the plug leads to various parts of the engine. This is robbing you of ultimate high tension voltage where you want it which is at the plug. Be sure to position your HT leads away from such proximity spots or install additional insulation there to prevent this arcing but be sure to do it with the engine off orthewise you may incurr a shock.

If the distributor is original, it may also be due for a calibration of its advance curve as the springs do lose tension.
Transaxle Alfas Haul More Arse.

Current Fleet
Alfetta GTV6 3.0
Alfetta GTV Twin Spark supercharged racer
75 1.8L supercharged racer

Past Fleet
Alfa GT 3.2V6
Alfetta GTV 2.0
Giulia Super 2.0
Berlina 2.0

alfagtv100 (Biggus)

Hi Berlinaman,

I had an Alfetta unit installed on my 1750 about a year ago.  The ease of starting has become remarkable in its consistency and reliability.  The car also stays 'in- tune' for longer, even after choking in stop-start traffic and the power delivery has been improved from about 2,500 rpm.
Not sure about the unit in your photos but I can definitely recommend you consider something.  I received some great advice from the guys at Maranello Pur Sang Motors at the time.
After Koni's, springs and 2lt cams, I consider it the next best upgrade for these cars.

Cheers,
Marco.
Marco Leoncelli
2017 Giulia. Yeah, baby.
1971 1750 GTV Coupe Series II
Past: 2008 159 Ti V6 3.2, RenaultSport Clio 182 (smuf blue).