i have hit a wall with my engine conversion, the L20b i bought has got water in it, not a good thing. as much as it is a pain in the arse its a good chance to do a full rebuild.

with everything apart im going to do some mods, wat valves can i use to open the head up a bit so it breathes, and how much.

wat is it worth to get the head reconditioned?

i pretty much have got a fair idea of the rest of the problems and their cost.

the gearbox better be good or else.....

well i reckon before u rebuild the head.. u should find an A87 head

an A series head is usually round the $100 + part costs

Or you could look at this webpage & get a few ideas, & maybee even some parts.

L series heads have 2 valve sizes:
big valve: 44In 35Ex
small valve: 42In 33Ex

and 2 inlet port sizes - 38 and 33 I think. too long since I've thought about that.

Even highly worked engines rarely go much bigger in the valve sizes than the big standard valves. Better to clean up the ports a bit instead. I posted some pics of my old L series head in the engine section if you want to track them down for a look.

the L20B should have the U67 head. That's one of the big port, big valve heads, but has open chambers. That's OK though. You can use L28 flat tops to get good compression out of it. I think the std L28 size is 87mm, which is .040" over for a L20B. Combine that with a mild cam, say 32/72 and a carb upgrade and you'll have a good strong street engine. Lighten the flywheel a bit too if the budget will stretch that far. And an off the shelf HD clutch upgrade is the Sports 2000 clutch.

Wouldn't be too worried about the gearbox - they're tough as nails

thanks alot.

i got the head of this arvo and its not as bad as i thought, its gonna need a bore and a hone though. my old man is making a stand so ill get the bottom end out over the next week or so. then poor some money into it.

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and that's the perfect context for it too...

yeah its a piss off too. i was under the impression that the engine was good, and i was hoping to get it in before my trip to coffs harbour, after all a 2000cc with a five speed is a lot better than a 1200cc with a four speeed to do a schoolies trip in.

but sh#t happens. the good old Aseries engine will make in a heart beat. (heart beat meaning easy not the speed)