Hep with engine rebuild

[teazer]

The valve seats look pitted. Pistons appear to be 0.5mm o/s and don't look as if they have done many miles.

With the engine together, get a compression test hose with a compressed air type snap on fitting like this



Use the hose to pressurize the motor, one side at a time and listen for the air leaking out. You should be able to hear whether it's mainly leaking down one of the ports or past the rings. Repeat on the other side and report back please.

I suspect that the head will have to come off to have the seats and valves professionally cut.

[Bernhard]

Right: 120
Left: 105

Is that decent?

Forgot what left was before but the right was low, like 40ish.

No, Left is too low.
You should have poured neat petrol into the inlet/exhaust ports in turn to see if valve seat as they should while head was off. This is a pretty severe test but a good home mechanic bodge.
Bore looks either re-bored or cleaned up with a honing tool. (or both, as it should be)
Check valve stems with micrometer for wear and see if any side to side play when fitted into valve seat.

[Jethro]

Was the engine hot when you checked compresstion?

[skisurf]

Yes, engine was operating temp when tested.

Any particular reason why I would have the valves seats professionally cut? Can't I just get the tool & blades and DIY. Doesn't look any harder than lapping.

[davomoto]

Besides the cost of the tools, you really do need to know what you are doing. Valve seat height etc must be correct.

Davo

[skisurf]

Would this method not work: http://www.youtube.com/watch?v=QIVj_L1akl4

[Jethro]

I would get ahold of loud mouse. He does head rebuilds for hire and does a really nice job. He does the valves, goes through everything and replaces anything that needs to be replaced including advance springs. When you get it back, it's ready to intall. Pretty reasonably priced too. I'd say it would be well worth it. Send him a PM for details.