New vs Reconditioned.....

[pfgiz]

I’m about to start on a 948 engine rebuild. I’ve asked some questions recently and have gleaned the following;

• A good head to use would be a 12G202 with 60thou skimmed off it. This gives you bigger valves and, thanks to the skim, keeps the compression ratio.
• A nice to have would be a 1098 cam shaft, as this has a higher lift than the 948 unit.
• To get a silent timing chain use the later mini setup but this may result in a replacement timing chain cover being purchased.

What my question is now is; should I use new stuff or strip the parts from old engines?

I’ve read many posts about the quality of some of the parts available on the market today and the fact that some of the pattern pieces are not fantastic. Is this the same for engine parts? For example, the 948 in question had a problem keeping oil pressure when the oil got hot. This I thought was an issue with the oil pump, I can get a new one for less than £20 but is it worth it when I can strip a known good one off a 1098? At the same time would a new cam last as well as the one off the engine about to loose its oil pump????

I’m just getting things together at the moment and wanted an idea as to the pros and cons of using ‘new’ parts against NOS, reconditioned or stripped known working parts.

I hope I haven’t opened a hornet’s nest, did you notice I didn’t mention brakes once? I’m saving that one……….;)

[bmcecosse]

Camshaft (AEA 630) will be fine to use secondhand, and get the cam followers with it if possible and inspect them carefully renewing any showing any 'pitting' - but I suggest a NEW oil pump is always wise. Cylinder head (12G 202) also fine secondhand - but you may want to fit new guides, and possibly new exhaust valves (and much less possibly - new inlet valves), and stem seals of course - and the timing set-up from a Mini will probably be fine - but I would always use a new chain - and inspect the sprockets carefully - especially the little one which works twice as hard as the big one ! A new pad on the tensioner would seem a good idea too, and of course a new oil seal in the cover.
Re - Oil pump - It's unlikely to be the only reason for poor oil pressure - which will be down to worn main and big-end bearings.

[pfgiz]

Re - Oil pump - It's unlikely to be the only reason for poor oil pressure - which will be down to worn main and big-end bearings.

So I'm going to need to get the bottom end sorted too. New crank or regrind? The 948 never burnt any oil so I'd guess the rings and piston stuff was ok.

[bmcecosse]

Certainly will want inspection - then decide what's required.

[ssnjimb]

If doing a rebuild i would still change the rings and glaze break the bores that would be if it was me.

James