Due to very low compression in #3 and generally low compression in the rest I have yanked my B20 engine and begun a teardown. I have found light scoring in the bad cylinder and it is unevenly worn with a max size of 3.516" and a min of 3.510. The rest of the cylinders have similar wear ranges but are much more evenly worn with the max wear at the top perpendicular to the crank and the minimum at the bottom inline with the crank. Light crosshatching is visible in the better cylinders but not in the bad cylinder and there is no perceptable ridge at the top of any of the bores.

I have not taken the bottom end apart yet. There was some very small pits on the bottom of the lifters.

I went and talked to the most reputable machine shop in town and here are some of his recommendations without looking at the engine:

Reuse head and bottom end bolts.
Replace at least the exhaust valves and springs.
Replace the camshaft and lifters.
Don't reuse the fiber timing gear and replace with aluminum set.
He said that even though the crank journals may be OK, oversize bearings may be necessary in order to reface thrust surface on crank.

His high quoted price (worse case scenario) was 1,100 dollars for:
Clean, Magnaflux, bore & hone, deck block, cam bearing install, pin fit/rod align, recon rods, grind crank, reface flywheel, balance, r&r guides, install valve seats, valve job, and surface the head. Sounded reasonable to me.

What do you think of his recommendations? I thought that springs were generally reusable as were timing gears? I also thought that bottom end fastener replacement was a good thing? Any suggestions or thoughts, this is my first rebuild.

Thanks,

Mario m.