Help/advice repairing a failed headgasket please (pic heavy)

[Adrian89]

Hey,
Basically I bought this engine very cheap because of the failed headgasket (the casings, sump and carb rubbers are worth way more than I paid for the whole engine).
So I originally bought it with the intention of having the sump off it for another engine but thought while its there I may as well learn a bit from it. Anyway, the cause of the failed headgasket is currently unknown, although it looks like it initially failed between 1+2 and 3+4 at the hot points.
Basically what would you do with it if it looked like this, the photos are of it straight after taking the head off, so I haven't actually cleaned any of the crud out. It looks in a pretty bad way:









My engine situation is I have an excellent one in one of my bikes (the one I ride), this one (no.2) , another engine(no.3) I swapped out of the bike I ride because it was making a slight tapping noise in the head to the left side of the engine, and a fourth (no.4) that used to hop out of gear quite a bit and also never ran properly (mainly due to very poor carbs and a nackered regulator).

Now I am confident taking the camshafts off as I have learn't from this engine, so would my best bet be to see if the engine making the slight tapping noise (no.3) is just a valve clearance issue? Or shall I clean this one up, put a new headgasket on it and see how it goes? It turns out valve stem seals cost more than I paid for all three engines lol

Any help, experiences, advice would be greatly appreciated.

thanks

from Adrian

[Adrian89]

Update, the previous pictures don't really tell a lot, apart from everything was filthy, now I have taken the cylinders and pistons off as well and given it a bit of a clean, everything looks ok and it doesn't look like the piston rings have failed/damaged at all.
There is a very slight side to side play in the conrods which I suspect is normal?
I'm still unsure what the main cause of this gasket failure has been, is there anything I should check such as the oil pump and cooler etc in the lower/bottom end?
Basically I think I have decided to clean this all up, put a few new gaskets in and see if its ok.
The haynes manual says the rings can be cleaned and reused, I'm inclined to go for this as it would save me £80, anyone got any other thoughts?
Also has anyone got a good suggestion on cleaning all these bits and pieces? I have heard of 'dishwashing' stuff (obviously not the head as that would just be daft)
Cheers

[leopard_pagan]

no idea if the same applies.
my 3cyl van gasket has gone, i have to have my head pressure tested for cracks/leaks then have it skimmed as it has warped. this will cost me in the range of £63-65 all in.