Miffi’s Machine shop report

The next step after the teardown was measuring and a visit at KS Motortechnik. Even though the camshaft has no pitting or bluing the conclusion after measuring was to replace it. The workshop manual says that lift height should be 6.35mm ( 6.45 to 6.60 the default).  The lobs had between 34.05-34.14mm.  Subtracting 27.60 mm for the diameter on the round part of the lob showed that all are above 6.46mm.

But all bearing surfaces were below the acceptable values. For this I looked up the inner diameter for the three bearings and subtracted the clearance. The center one for example had 41.14mm – roughly 3x of the allowed clearance.

The standard cylinder bore is 70.612 to 70.638mm and I set the dial to a valve in-between mm. Then I took many runs to measure three heights in X and Y direction on all four cylinders. My verdict was that the middle section is too far off – but really more by looking at the differences on the gauge rather than doing the math. Being unsure if I did it right we repeated this at the machine shop. To my surprise KS didn’t do it any different and the result was to bring the bore to +0.020.

All journals also require grinding to the first undersize. I left the crankshaft with them the price for grinding and polishing is 370€. Without flywheel, clutch and damper balancing does not make much sense yet. As I plan to get these parts in the UK on my next trip – the idea is to find a Mini specialist in the UK. I already reached out to MED for this – but have not received an answer yet.

Removing Core plugs and oil gallery bungs as well as cleaning the block another two hours. Some of the old gaskets gave quite a fight to get them off. The engine number badge came off without damage. For the pop-rivets tried the recommended counter clockwise turning. This did not work out. So I flattened the top of the rivets, used a punch and drilled. Then I tried an counter clockwise turning extractor – but only got the heads off. The remains of the rivets now also need to be drilled out with a 4mm drill.

To bore out the block the machine shop also needs the new pistons. These will be die-cast 1293 with a 6.5cc dish which are coming from Swifttune. On the cam side of things I originally considered the Swiftune SW5. But now I am leaning to the MED HT profile. There are quite a few more MED parts on my wishlist. In the next couple days you will see a new page here on the blog on this topic.