Update!
The frankencarb was pulled apart and dunked in an ultra-sonic cleaner and reassembled. Fuelling problems all sorted and the car ran really well and would start instantly (once the mechanical fuel pump had brought go-juice up to the carb).
I was planning to attend Festival of the Unexceptional, which the car had failed to make last year due to the engine being fucked.
So the car was given a quick polish and I started refitting all the stainless trims etc.
Interior was given a clean with the wet vac, door card hardware was all reinstalled and the dashboard/parcel shell refitted properly.
A mini amp and a pair of stereo speakers were wired up to sit on the front parcel shelf under the dash to provide modern ICE. Sadly somebody has already cut holes in the door cards for speakers, so I need to find un-fucked ones.
I also wired in a 12v socket, for charging phones etc. Fuses are hidden behind the stock radio.
Drained and refilled the gearbox.
Then the coolant system was flushed out.
Naturally the bonnet release cable then snapped (ideal on a car with a reverse hinged bonnet with no easy access to the latch...), so I replaced it with some electrical wire poking through the vents on the top of the bonnet
I took it for a quick spin around the block post coolant swap in the evening and it seemed fine. Then I had two days at works where I was out 12-14hrs so it never moved. The following morning was spent loading it full of stuff for the 340 mile, 6hr drive to Peterborough.
Things went well, the car was running nicely and happily sitting at 70mph on the motorway. We were running a bit late and were meeting people for a convoy down at Hamilton service station. About 5 miles away from the meeting point I noticed the temp gauge had risen to the 2/3rds mark.
This isn't normal. The Dolly has always ran pretty cool, it usually sits around 1/3rd on the gauge and never really goes past the 1/2 mark.
I backed off a bit came down to a 50mph cruise speed but the temp wasn't dropping. Not wanting to stop at the side of the motorway with the girlfriend in the car I pushed on and we arrived at the services with the gauge reading max.
Also, upon pulling into the services I heard something "clunk" off the bottom of the car and saw something roll off towards the lorry park in the rear view mirror.
Parked up the, now boiling over car, and went to investigate. Imagine my surprise when I found the crank pulley nut lying on the ground...
This was reattached with some Loctite to prevent further escapes.
This was a bigger issue though.
Frothing out of the rad when revved, pulling the oil dipstick caused the revs to drop so much the car nearly stalled. That'll be head gasket failure then...
No signs of coolant/oil mixing, but compression was definitely escaping.
The car was limped home with the thermostat removed with further overheating issues and we swapped to the Volvo for the trip.
My best guess is that there was an airlock in the coolant system somewhere and that caused the overheating and subsequent gasket blowing. I confess to not paying much heed to the temp gauge as the car never really runs hot... The head gasket that's installed is a generic cheap one as decent quality Payen ones were out of stock everywhere when I built the engine so they're not the most resilient.
I left the car sitting for a while once we returned as I'd lost mojo but over the last two days I retorqued the cylinder head and it no longer seems to be pressurising the coolant. I need to reinstall the thermostat and put some miles on it to verify there is nothing amiss. Worst case a head gasket is a 2hr job.