Ozmadman wrote:Thanks all, would you risk using an old copper gasket? + what stuff would you use to do the grinding if I needed to?
Paul
Paul. Rob is technically quite correct in suggesting the good practice of 'grinding in' ('lapping' would be my choice of word) using valve grinding paste. Ensure that you identify which areas of the head and barrel are the actual mating surfaces. However, as Colin says, unless there is an obvious mismatch or high/low spots I'd leave well alone. That said, it's a bit concerning that the P.O. who is believed to have overhauled the top end, has used some sealant on the gasket 'twixt head and barrel. He may have had a sealing problem or may simply be someone who slaps sealant on every joint. He may have failed to anneal the gasket (even if a new one was used as Colin commented) or not tightened/retightened the head bolts sufficiently. Personally, I would use a new copper gasket as you don't know what has happened to the old one, and anneal it. I don't think your icing spatula would work and you could do more harm than good; it's best to lap the two surfaces together, simultaeneously, at the same time, also, innit.
At risk of being boring (or of being condescending as I was accused when I last posted these pics) here's a couple of pics of annealing - heat to cherry red all over and drop into cold water:
The sudden cooling isn't strictly necessary but it does shake off any crispy bits from an old gasket
The zorst port does look a bit cokey - was the inlet valve oil feed screw set correctly?
Sorry if I'm covering what you already know but it saves time and may enable you to crack on if I answer thoroughly rather than have a cascade of Q&A posts. Anyway, another cold grey day here (like living inside a ping-pong ball); I've picked all the fluff out of my jacket Velcro, the car's in for service, the dog won't get up for his walk, the grass is too wet to cut and contractors have severed the water main
so I'm just passing time..........
I don't think you have any issues with the head other than the spark plug thread, I mean the engine doesn't smoke so I would leave well alone, now the head is off grind the valves in, fit the copper gasket, anneal it even if its new and torque it down as per manual.
