Do any of you learned folk know why early A+ 1275 blocks were linered from the factory.?
I've got a couple of short motors here, one of which is definitely out of a Metro, and neither have the "WEM" script cast into the block.
My thoughts are that the bores were porous from the foundry and the blocks were sleeved to counteract the porosity.
My RSP block is not linered, but the RSP engines are MG Metro based which confuses matters somewhat.
Yeah, supposedly some were porous and when you 'feel' and closely look at them, IMO, they are pretty crappy, with a fairly course grain to them, probably cast from what they swept up off the foundry floor,,,,
I've not seen it published anywhere, however ALL the early A+ 1275 Blocks (I'm talking 1979 and maybe early 1980) I've had my hands on have bores that were not perpendicular to the crank line. At a guess, I'd say there was something 'up' with the jig they were using as not only have they been out, but all the same way and roughly by similar numbers. It's possibly too that as they came across these, they put some / all aside for Aust too and it's possible that some may have also had liners fitted to correct them. Last one I had in the boring machine we had to take out from a slightly worn standard bore size to +0.040" to get it to clean up properly.
Last edited by Spider on Sun Mar 13, 2016 2:26 am, edited 1 time in total.
Vizard refers to this issue with 1982 1300 A+ blocks.
He says :'the chances are such a block will be linered due to boring problems at the factory.' He adds....
'These blocks are OK up to +40 overbores for moderate performance applications but not advised for all-out race engines.'
He also mentions another 'factory problem' on these blocks. On some Metro blocks the block main bearing oil hole to main bearing shell was drilled outside positional tolerances at the factory. Not a problem on a road engine but not good on a high performance engine. Simple 'fix' was to chamfer the hole in the block.
Thank you for the replies chaps.
I imagine that when the 1.3 Metros were introduced, to keep up with demand, quality control in some of the manufacturing processes was not high on the agenda.
