Miffi’s 1275 A+ Engine (12A) Rebuild (Part 2): the lower part

The engine is slowly coming together. Turns out that it was a bad idea to use the universal tool to knock in the camshaft bearings. This caused a very tight camshaft due to minimal edges. Too little for line reaming. I had the machine shop correct this and spend the money I thought I could save when changing the bearings myself… Oh well.

K&S Motortechnik confirmed that the discoloration of the cylinder bores is not nice but also not a problem. The entire block was cleaned again and this time I apply oil to the bores after every garage session. The Plastigauge (which I found in a different Eurobox than expected) test of the crankshaft shows that it is in spec. There is only one picture below – but I tested all three main caps as well as the Conrods.

The crankshaft endfloat is also perfect. The universal piston ring compressor works – but if I could – I would get one of the MED installation tools. These are tapered and a lot easier to use. Cam followers are inserted from below into the Mini A+ engines – I used lots of Lucas assembly lube on those. Even though I went thru all the threads before painting the block, the ones for the oil pump needed a second round.

For the gaskets I am using Hylomar M this time instead of Loctite 5980. This is only used for some o-rings and the rubber half seal.priming the oil pump with assembly lube was recommended – but the truth is that most of this will flow out into the block after two nights. Core- and oil gallery plugs got a light smear of Loctite gasket sealer on the edges before pressing them in.

The MED(Piper) vernier includes different bolts for the camshaft retaining plate. Endfloat of the cam was also exactly within spec. The MED HT cam needs 109° – it took me quite a few attempts before I had this spot+on. The gearbox has an o-ring and I very carefully used Loctite with this – last thing you want is silicone in the oil channel.

Next up is the cylinderhead, transfer-case, flywheel and clutch. Fingers-crossed – first start might be next weekend.

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