Firstfives.org

I remember you've said:
"I next gave the fuse box a couple knocks on the side with my knuckles and power came back!!"
This is another reason to check the fuse box, the fuses and the springs of the fuse holders. Examine the cables and connections underneath also.
And yes - it is strange, that the ...

Thank you Bart (Falkenberg). I see - we wrote our posts almost at the same time...
You were a bit faster than me, but the main idea is similar (Mike was the fastest... ).

The main consideration is based upon you've said:
"Everything died when turning the headlights on and came back, when turning them off"
1. You have "bad connection" problem.
2. As I understand, when you turn only the ignition switch, without the headlights - the starter turns vigorously and engine ...

Yes, the answer is "yes"
But the AC edition isn't fully interchangeable with the no AC version.
If your fan isn't working - firstly check the fan itself, then the resistor block (for the fan speeds) and cables also and after that the switch.

Maybe my reply is a bit late...
Sorry...

But, firstly, Bart (Falkenberg) is right - the old original BMW rockers are better than the aftermarket ones, like Febi for example. Generally the rockers from e12/e28 era are better (stronger) than e34 era.
If you want to have some new ones - maybe these ...

If you don't plan to double or even triple the devices, which will consume 12 (14) V, for example an additional battery, real 1kW audio power amplifier or more, high power xenons and so on - it is unduly.
It will be better maybe, if you share your plans, then we can give more adequate advices.

If you tell me - the compression figures are around 12 bar - I'll say - it is normal. It is very strange to have 14.1 bar compression in such engine. As for me - these numbers are too high.
However, the bad thing is, when you have big difference in the compression figures - in your case from 11.5 to ...

I saw second oversize pistons 86.50 mm on eBay (Germany) - for only 50 Euro (all the six pistons). It was maybe seven-eight months ago.
As for the third suggestion - I'm sure - it works fine (I have such engine) - without any sign of overheating. I use the original old e28 pistons with new rings and ...

:) I also had Zenith Inat carburettors on my first e12.
It was a real "drama" to synchronize them. You know - there are "only" seven adjustment screws. In my case, after a proper adjustment, everytime they gone loose in some way - fixing the screws didn't help. Three of the cylinders were always ...

I didn't fit yet the e32 M30B35 engine in my second e12.
Yes, you are right - the engine mounts are different. Here in the forum you can find the needed information. Also you can browse the MyE28 forum. There you can find similar topics with good explanations and pictures. Some of the FirstFive ...

We have discussed this topic maybe two or three years ago.
I've posted the same topic at the MyE28 forum.
Some of the forum members were of the opinion, that it is possible to bore the cylinder walls from 86 to 89 mm. Some of them even did this. With no doubt - the engines ran and maybe are running ...

I thinked a lot, before I decided to post my reply...
I know - some of you will say - it is unduly.
I use Selenia 10W60 fully syntetic in my Euro M30B28.
I'm "in a hurry" to say - I did this after an engine overhaul.
As a first step I used some Shell semi-syntetic - I even didn't remember it's ...

The exact spacing of the front caliper mounting bolts is 89.3 mm
Converting to inches - 3.516"

I'm sorry to say this (how I wish I am wrong) - but probably you have locked (blocked) the engine. Your last tests were with "running" engine, but the car was not moving - so we presume - the problem is engine related, not other moving parts as transmission, clutch, drivetrain and differential.
If ...

I have installed 75Ah battery on mine e12 (2.8i engine, without AC).
Talking about 90 Ah - I'll say - it's OK if it fits mechanically, but 75-85 Ah is enough.

The PROs - will last longer, because the maximum load current is higher, compared to 65 Ah battery for example. Bigger battery will cope ...