OK so some issues have now been fixed ...
Only running on choke when hot
This just shouted 'fueling issue' to me but I wasn't sure how because the mixture was right, and when cold it ran fine, so why would it lean out when hot...no idea right? Well I decided to strip the carb to see if there were any blockages, so i started to remove it. I started to remove the fuel pipe union and after only half a turn or so I was sprayed with high pressure hot fuel! It went everywhere... thats odd I thought... never had it under that pressure from the mech pump before. Which got me wondering, was the fuel over pressurising because of the damn hot engine? was the fuel vapourising in the float chamber or the jets because of the damn hot engine? Is this possible?
Anyway, by my reckoning the carb was getting too hot because it was too close to the head, so I fitted the stromberg I have, because it would be further away and would stay cooler ...right? I took it out for a spin and no issue with going lean. Ran like a dream...and pretty bloody nippy too
so fuel problem sort of solved ...maybe
Back to over heating ... I had changed oil when I first did the headgasket, but the next time I didn't. neither did i change it when i swapped the head.
Lets talk about the head swap, I didn't tell you guys what I did for fear of being ridiculed or something...but i'll come clean now.....I fitted a 1256 head
0n purpose, as all I had was a 1256 head spare but i figured the engine wasn't working so i'd try anything
I made up sleeves for the 3/8 bolts so they were centralised in the holes in the head and didn't rattle about or let the head move as the 1256 takes the bigger bolts. and used a 1256 gasket fully smeared with hylomar ... yes I know ..it sounds like a lash up...and it
IS a lash up but.....
Anyway...first run after the swap i got over heating and bad carburation as normal (this was before the carb swap)... but it was different...it felt different, don't ask me how it just did. So i did the carb swap as mentioned above...then, I decided to flush the old oil out, with a volatile mix I have in the shed for cleaning parts, it is mostly old engine and ATF oil, with old petrol and a liberal dose of acetone, plus any other fluid I drain out of anything...it's pretty lethal stuff, so i filled the engine, I mean filled it, right up, overflowing , hand turned it for a bit to get the gunk all the way around the old girl, and left it to soak for a bit. Then i drained it out, and topped it back up
with the same mix and crossed my fingers and started the engine... ran it on fast idle for a bit, turned it off and drained the *Bleep* out. topped up with fresh clean oil and ran it again......
It took ages to get up to temp, well about twice as long as before, it then started to creep over towards the 'damn hot' mark, but flicking on the heater fan made it drop right back to normal ...which it has never done before, flicking the heater fan on hasn't even blipped the needle before, but now i can bring down the heat with the switch as normal....
Now i'm not saying it's fixed... but it's behaving differently so there is light at the end of the tunnell...
More tests will ensue, but I am a little more hopeful that my 'Frankenstein' engine may just work