An alternate alternator and other findings

The main reason I got a trailer for the Morgan this Monday morning was the issue with the alternator that came up last weekend. Instead of adding this to the tasks at Viktor Günther Motorsport – I said that I will get a replacement myself. Interestingly – at VGS the alternator sporadically functioned just fine.

The first challenge was to find the right part number.  Over at the TalkMorgan forum Arwyn pointed out the Lucas LRA00604 alternator.  But at least the one I could order had different connectors for the B+ cables. But with this number I was able to find the Ford alternator OEM number 82FB10300EA. This is turn made it simple to order a replacement from Autoparts. A 55Amp Herth+Buss variant turned out to be deliverable right away and I picked it up early today.

After work I headed straight to VGS and arrived just 20min before they close. Removing the old alternator was a quick and easy job – the new one is just a tiny bit bigger and it took me 5 min to wiggle it in. They also gave me a run down on all the things they found.

First up is the ignition timing. VGS says it should be 12° BTDC. Reading in my own notes here – I tried to set it to 8° BTDC because the Ford manual states the value for unleaded fuel. Well, I only set it to something 6° and that was clearly not optimal. A bigger issue is the new Mototronics distributor. It should advance up to 28° under load – which it doesn’t. To compensate the problem VGS set the idle timing to 18° BTDC. This will work for now, but I will request a pricing for a 123 Ignition conversion.

Problem number two is a tiny detail. While overall my overhaul of the Weber carb turned out to be OK – the top cover assembly was missing an essential element. I would have never found this problem because neither the Haynes book nor the parts diagram list mention the part. The top cover assembly is always shown as a single “no servicebale” item. In the picture below with the red circle you see the missing ball valve. Through this channel the carb gets more fuel unter full load. Back at my garage tonight I immediately checked my spare Weber 32/34 DFT and this has the valve (green circle).
What happened? The top assembly on the currently installed Weber is from the spare Weber 32 I bought. The top cover assembly on the original carb was broken. The one form the Weber 32 looked identical – I did not notice this slight difference. VGS did and fixed it.

The broken alternator also caused an issue with the AutoChoke. There is a blue-white cable running from the B+ port of the alternator to the Autochoke. The current causes the bimetal in the Autochoke to expand – which steps down the choke. A simple (crude?) mechanism. As the alternator did not charge correctly – the AutoChoke would also not get power. Hence it would not quickly step down the choke.
VGS used a piece of blue cable from the idle cut-off solenoid and extended it.

The reason for the “high temperature” on the Smith gauge is a faulty temperature sensor. The connector for the cable is fixed with a rivet and this is loose. Depending on the engine vibration and position this causes to much resistance – leading to 120° on the Smith. I need to find and order a new sensor.

The new 55amp alternator should also fix problems VGS found when the Revotec fan is running. This is the item that draws the highest current when running and the old 36amp alternator had problems with this.

They also tested the engine, and it only has an output of 86 HP. Ford specified it with 95 HP. VGS believes that the exhaust is too restrictive – as it really makes the car quite silent. Right now, I don’t care about the power that much – all I want right now is to get it driving again. Tomorrow I can pick up the car – really looking forward to doing the first longer test drives now.