I recently bought a 3.9 engine off Ebay. Paid 210 quid. Described as being in good working order when removed from vehicle with overhauled heads and recent replacement camshaft. Camshafts usually last about 100,000 miles so that was the sort of age engine I was expecting. My intention was to strip it, check everything, have the bores honed, the crank polished and fit new bearings and rings.
On arrival it didn't look good. It was bought without inlet or exhaust manifolds and the valley gasket was very rusty. The ports had kitchen paper stuffed in them - which was wet.
On stripping down several bores were full of water as was the sump - which had been drained of oil. The tappets were worn - good ones are flat on the bottom, these were bell shaped. I didn't have any measurements for a new cam lobe, but the lobes varied in height by over 4mm. So the cam and followers were scrap.
I cleaned up the rust from the bores as best I could without using abrasives and removed the pistons. The thrust side big end bearing shells had copper showing - but no scoring. Mains looked fine. The crank wasn't rusty and showed no wear I could feel between big ends. The bores didn't appear to have a lip at the top. No rings were broken.
I've had a machine shop check things and they say the crank is fine but the block will need a re-bore due to the rust.
What would have been a fair price for this engine? The seller has responded after I've put the matter in dispute with Ebay as not being as described, but I'm unsure what would be a decent settlement. Ie, what would one expect to pay for an engine in unknown condition which had been badly stored? The rebore, new pistons and camshaft with tappets will cost me in excess of 500 quid.