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Hey does anyone know if you can get a replacement bosch cap for the 123 distributor from a local auto shop? Does it match up with something stock (VW maybe) or do I have to order from IAP?

My distributor cap broke the piece that rides on the center of the rotor already!

Thx, gene
 

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Just read the thread with a lot of interest.
I have a Giulia Super from 1972 with a fairly warm motor.
I had the car on a rolling dyno last week and we were only able to get 146BHP out of the engine. At the same time it also had trouble falling back from high revs - settled at around 3.000 rpm every time.
Looks like I am in for either a new stock distributor or a 123.
It seems that there is a lot of advantages with the 123 in comparison with a stock one.

And while 146BHP is a nice power output in combination with the drivetrain, shouldn't it be giving even more considering the engine modifications - together with 46 DCOE Webers.

The car has been built for fast road & track days The engine, gearbox, diff and suspension have all be optimized with lots and lots of great parts:
High compression forged AE pistons 10.4:1 and the head has been shaved a full 1.2mm
Conrods/connecting rods have been blueprinted/balanced
Inlet valves are 46mm from BMW
Exhaust valves are 38mm stainless steel
Camshafts are Colombo & Bariani AR.ST1 292/292 degree

Rear axle is 2000GTV with LSD with a 1600GTJ 4.56:1
Front suspension has new bushings, adjustable camber, and hub, ventilated discs and 2-pot caliber from a Montreal.
The Gearbox is a special built unit from Finland - close ratio (FIA - specs) as GTA :
1. 2.54
2. 1.70
3. 1.26
4. 1.00
5. 0.86

So my questions are:
1.) Will the 123 be the the right choice compared to a stock, rebuilt unit?
2.) Is there a chance that the new distributor will solve the fast idle problem - the carbs are in total balance and mixture is fine, if a little bit rich up through the rev range
3.) There is not a support for the carb. flange - can this influence the high idle speed?? Carbs are mounted with solid aluminium mounts and not rubber ones!

Any help will be appreciated.

P
 

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Discussion Starter #23
Is there a chance that the new distributor will solve the fast idle problem - the carbs are in total balance and mixture is fine, if a little bit rich up through the rev range
Probably yes. I am using the "006 tuning" curve and my engine idles at about 700 rpm. I had the high idle problems when I used the "Shankle" curve. I have RJ136/785 cams.
 

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Hi Per, I have an engine which sounds quite similar to yours -- I got a 123 distributor and with the 006 curve it dynoed about 180 bhp -- which was fine. However I was never able to get it running consistantly well on any of the curves.
I have since gone to an RML with MSD and the motor has been fine since, I think the MSD is one of the best things I have done to the car.
I then put the 123 on a mild 2 litre using the 045 curve and it ran great, started easily, idled, gave good power etc, I trailered it to a track day 2 weeks ago and the 123 decided to give itself 40 degrees of advance at idle ( straight off the trailer ), car was undrivable of course so I put in an old points dist. for the weekend, the engine was just as powerful, started just as easily, didn't idle so well. Not sure if I am going to put any more time into the 123 or turn it into a museum piece.
 

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Have other's had similar problems with their 123 that Hans-Peter is having?

I've been planning on getting a 123 for my clients fairly warmish 1600 engine. He's becoming a bit more cost conscious as the restoration of his '66 GTV continues, so the last thing I want is to have an expensive distributor turn into a doorstop.

Do they have a decent return policy? Often electrical items are 'no returns' deals.
 

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Discussion Starter #26
I have had no trouble with mine in 4.5 years and several tens of thousands of miles. Mine has been hooked to an MSD 6AL for quite a while. I have a high energy Blaster coil and my plug gaps are set at .055" and there is no sign of breakdown in the distributor cap. Prior to that I used a Bosch Blue coil.
 

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Distributor Cap and Rotor Condition with MSD 6AL2

Hi Ed, you mentioned that you didn't have any problems with the condition of the distributor cap, lucky you! I've just done about 2000kms, maybe a bit more, and here is the condition of my cap and rotor (I am running the MSD 6AL2 programmable with the stock dizzy (advance locked out)) . yowza! I noticed that starting the car was a bit less crisp than when I first installed the system, so figured that it was probably due to a slight shift of the timing (from wear of the points) as the points are still the trigger for the programmable ignition (although high current no longer flows through the points). of course the points gap had reduced to about .25mm instead of .35 to .40 so this of course means a shift in the advance, and the condition of the points was near perfect, but the condition of the rotor and cap was quite surprising, I put a new cap and rotor on when I installed the ignition (so 2000-ish kms). I reset the points gap to 0.4mm and replaced the cap and rotor with the original ones I took off when installing the MSD (which wern't really worn much), and of course everything is great, as new. Is this what your cap and rotor look like? I can't say for sure that this is the cause of the (very slight) deterioration of performance of the ignition as it could have been simply the shift in advance from the points wear. But certainly I've never seen this amout of "burning" on the cap and rotor with the standard ignition. Still not complaining though, the ignition is truely excellent, and transforms the low end behaviour of the car.
cheers / andrew
 

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Richard Jemison
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What`s the point?

This has nothing to do with the MSD unit. Obviously a worn out points dist that needs new bushings and shims to locate the shaft correctly.
 

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just thought it might be related to the higher energy pulse going across the gap, as I have never seen this before installing the MSD unit (using same distributor). By the way, there is no "gouging" on the rotor or cap (ie no wear from contact), it is all a carbon deposit, and it actually cleans off pretty well.
 

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Discussion Starter #31
I just pulled the cap and rotor on mine and they are in fine condition. They have done 24,000 miles.
 

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Interesting, thanks for checking. I guess I'll just have to keep an eye on mine from time to time. As I said, the carbon cleans off pretty easily so not a big deal.
cheers
andrew
 

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After seeing your post I took a look at the rotor and cap interior of my 2L. Yikes! Not sure what's going on. The rotor plastic has significant melting near the contact tip. It also appears that a hole has melted through the rotor arm through to the bottom. (see pics) Also attached are photos of the MSD 6AL, FireBall PS91.

I'm convinced this must have occurred during a 'little' incident before Dick & Bill at Engine Machine Services rebuilt it. A certain someone who shall remain nameless wound out the motor, fried the pistons and shattered the rings. After leaving the car by the side of the road, they left me a message telling me to where to find it and to come and get it. Well, yeah, that was an interesting discussion.

Anyway, do any of the Alfitsi community know if this setup in the photos is okay?

As always, thanks for any advice and suggestions you may have concerning the engine, that is.

Mike
 

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I have had this happen on both a Bosch and Merelli rotor. Some of them have resisters in them which heat up and cause the problem. You need to make sure you get older style rotors without the resisters. You can visually tell by the epoxy like grove in the top. When I've ordered new ones from International I have the sales rep open the box and look at the rotor to verify.
 

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123 rotor position

I"m gong on the basis that this thread is pretty much the repository for 123 info. If not, I apologize.

I want to get the rotor positioned reasonably accurately for now. I'm aware that the light will come on when it is positioned correctly once all is 'ready to go'.

On my MirelliPlex, I've found that the spark comes on a fair amount After the lobe passes the pick-up.

Yes, this has a rotor so I'm not sure if it is more like analog (just before), or after as on my MirelliPlex, or...?

As you can see, the rotor is positioned almost exactly between two distributor cap contacts. So which way to rotate the body to at least get it closer to the correct spot for the 123?
 

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Discussion Starter #36
If you set the 123 by static timing then first select the curve that you want. Then see what the static timing is for that curve. Then rotate your engine to that timing point. Then rotate the 123 dizzy until the light just turns on. It is that simple. You should then have no trouble getting your motor to run. Then fine tune the dizzy to get the max advance that you want at the appropriate rpm.
 

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Ed thanks. I'd just finished putting on the ends of a set of ignition wires and wanted to install them. Of course not a big deal to switch them around later. My big concern though is if the light comes on but it turns out to be for #3 rather than #1. Since my MirelliPlex fires well after, I'm gun-shy of most likely starting out with a Very iffy position for the rotor.

Also my first read of the instructions indicates I need a PC laptop to set it up. How this works with the wires that come with the distributor is beyond me (and I don't have a PC laptop), but Max at Alfaholics programmed in their own special program, in addition to the ones that come with it.

If this was an analog distributor, it would be no problem.
 

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Discussion Starter #38
I don't have any experience with the programmable model. Mine has a 16 position switch to select the curves. The light is not associated with any particular cylinder - just like points. No need to over-analyze it.
 

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Ed, I don't mean to sound ungrateful, but are you saying that if I try to start the car with the timing marks on #3 there won't be any problems starting it?

What I'd really like is that if someone has one of these and by chance the engine/pulley has stopped in roughly the region of the idle advance mark, pop off the distributor cap, preferably take a photo, or give me a pretty accurate o'clock time (for instance - 3:30) as to where the forward edge of the rotor is. You might even be a bit surprised if you've not done this before.

All I know now is that I've got to either turn the distributor body a fair amount clockwise or counterclockwise.

Again...an Alfa with an analog distributer, turn on the ignition switch, either put the car in 5th, and roll it, or turn the engine at the crank pulley until the points spark, then adjust 'as required'.

I've never gotten my MirelliPlex - to repeat which fires After the lobe has passed #1 (for instance) - to spark and assume it won't on the 123, but might well be wrong.
 

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Discussion Starter #40
Just set it at around TDC on the crank pulley like you would set points. It is no different.
 
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