Old Chestnut

Post by **XDB** » Sun Feb 24, 2008 8:39 pm

or with a hone tool in leccy drill)

do you mean one of these.[img][img]http://i218.photobucket.com/albums/cc17 ... C01042.jpg[/img][/img]

I have measured the bores which are standard and are in tolerance.[img][img]http://i218.photobucket.com/albums/cc17 ... C01043.jpg[/img][/img] The big ends and mains are 20 thou undersize they are smooth and just require a quick rub with fine emery.

this is the worst bearing shell[img][img]http://i218.photobucket.com/albums/cc17 ... C01017.jpg[/img][/img]

Post by **XDB** » Sun Feb 24, 2008 8:41 pm

I have already ordered the parts including new oil pump and timing chain kit, the only thing I am nervous about is setting the clearance of the rear main and crank.

Post by **bmcecosse** » Sun Feb 24, 2008 10:08 pm

That's the hone - you should use it to 'bust' the glaze on the bores. Or just use emery on your hand (if it will go up the bores - mine won't on a 1098 - but will just on a 1275) and work up and down the bores twisting as you go to create fine 45 degree cross-hatch pattern. If you don't do this - the new rings will struggle to bed in. Also make sure the piston lands are clean - and not damaged in any way. I wouldn't rub the crank journals with anything over than a clean duster! If that's the 'worst' shell then there is absolutely nothing wrong in there!

Post by **XDB** » Sun Feb 24, 2008 10:32 pm

The only other concern is that the engine has stood for years, it wasn't seized or anything, but by standing the cast parts of the conrods and cranks had a later of rusty particles. I have a set of conrods from another engine, is there a problem using these or should I just clean up the originals.
These are the two different ones side by side.[img][img]http://i218.photobucket.com/albums/cc17 ... C01022.jpg[/img][/img]

Post by **bigginger** » Sun Feb 24, 2008 10:39 pm

Shouldn't be a problem, as long as the caps and rods are the matched pairs that they were in the original engine
a

Post by **bmcecosse** » Sun Feb 24, 2008 10:45 pm

I think I would use the NON rusty ones! But pick the best of the pistons - PROVIDED they are all the same bore size and same 'dish' in the top. Interesting that the rusty one seems to have the later/newer Mini type bolts. Also - note the rods are right and left hand - don't get that wrong! And as 'a' says - DO NOT mix up the caps. You need to get ALL the hard black stuff out of the ring grooves - a broken ring makes a good scraper - but be careful to not scrape away any metal. You may find 'Carb Cleaner' from Poundland works quite well - but it is almost pure Toluene and so extremely flammable! I've also used the Alloy Wheel Cleaner foam spray from the same source - it's good on anything Aluminium - use it with a tooth brush - but wash the brush out well afterwards!

Post by **XDB** » Mon Feb 25, 2008 10:11 am

thanks both, the bolts were subject of an earlier post, the engine has previously been rebuilt, and has a label,

I bought it as a running engine to be bolted straight in, but I thought it would be prudent to remove the head and the sump to check its condition, good job I did. All in all it appears to be a good unit, and as a bonus the gearbox that came with it has also been rebuilt and a quick check shows the gears are in exceptional condition.[/img]

Post by **XDB** » Wed Feb 27, 2008 5:20 pm

Just an update, the dirty pistons are the best ones, there is very little room either side of the new rings, whereas the other pistons ones are quite slack. I gapped the new rings in the bore halfway down, they were just in tolereance so I just gently honed the bores so as not to make them too big.