Frankenhealer
I think if you had done this before I did the Cummins swap the I'd probably still have the Beddy engine
Steady on there! 
We all know it's never going to be great on fuel economy, or power, even fuel injected; but it will be interesting to see what can be done even just with better control over the timing.
dodgerover
Power could be sorted with a large blower or suitably spec'd turbo, wouldn't even need a decompression plate
"Luckily for all of us, turbochargers came along to solve the second problem, and make the first problem much, much worse." :D
I can't rule out a dynamic compression multiplier further down the line, but not for right now!
On a different note, I've spent an evening with a thermometer and a multimeter, characterising the sensors I'm using. I've only managed to get data-points down to 16°C or so, since that's as cold as I can get water from the tap and I can't be bothered messing about with the freezer; but I can get additional data at the unit, where it's an ice-rink, anyway. ...well, so long as I remember to take the thermometer, anyway.
So, as far as the sensor data goes:
IAT: Febi 30981 (1/4 NPT thread. 2-pin JPT connector.)
| Temperature (°C) | 68 | 53 | 45 | 40 | 30 | 16 |
|---|---|---|---|---|---|---|
| Resistance (Ohms) | 2000 | 3600 | 4500 | 6000 | 8000 | 13100 |
CLT: Cambiare VE375035 (Hole & retaining screw mounting. 2-pin Aptiv SICMA connector, green keying.)
| Temperature (°C) | 68 | 52 | 46 | 40 | 30 | 17 |
|---|---|---|---|---|---|---|
| Resistance (Ohms) | 178 | 340 | 440 | 650 | 720 | 1000 |
I still want to get colder points of reference, just to make sure I cover a range appropriate for all the weather conditions and whatnot; but that's a problem for another day.
Other than that, I ran the engine again today with a little bit less leaky of a fuel supply, so I had a longer run-time; and aside from it being cold enough that I could watch my fuel separate out into layers, it went quite nicely!
Side-note about ethanol blended fuels and whatnot
According to a study at the University of Nebraska-Lincoln (PDF), E10 can hold about 0.4 to 0.41% of water per volume before it starts to phase-separate. That's about 4ml per litre. Or 3.68 teaspoons per gallon (imp.), if you're that way inclined.
(And, of course, E0 or ethanol-free fuel can hold 0% water per volume, so any moisture that gets in there is likely to just sink to the bottom and collect as small puddles. So... seems like E10 is probably better at controlling the small amounts of moisture you get from condensation, so long as you're using the vehicle regularly?)
So it doesn't take much to get that separation, and that could well just be moisture from condensation, seeing as I've had that little plastic 5litre can in the boot of my car for a couple of months now.
I'd forgotten just how quickly that big lump of iron warms up; no need for aux engine heating on that thing! My next step has clearly got to be getting enough pipework on the engine that I can fill it with coolant even temporarily, so I can run it for longer without risking damage.
Now, the fuel supply's a little on the small side! With full choke on,
I only get a minute or two of runtime; and with all the thrashing it
did trying to start first time (...probably trying to start on nothing
but ethanol and trace gasolene, considering how badly it all separated
so quickly!) I did lose a bunch of fuel out of the top of it, which
was quite the experience. 
Thankfully there were no fires, and it settled down into nice smooth running with occasional hints of blue tickles of flame out of the ends of the headers. Ran just long enough to get everything slightly warm.
Following on from that, some ignition-lead tidying up!
