Installing Mini main studs

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	The four areas to be ground are shown painted white. The very best time to do this is obviously when the gearbox is stripped out, but if this is not the case...


	...then mask off the box carefully and use a burr to cut these areas, not an emery type drum. You were going to wash the box out again before fitting it anyway, right?


	The front web requires care, if you grind more than is required you can go through the case here. Do not cut in too deep in the corner, just cut a slight taper towards the inside of the box


	Here is the completed job. If you can see clearance, or can put a feeler gauge under the stud/nut then when the gasket is fitted there will be plenty of room.

What's wrong with the factory bolts?
Factory bolts, at the very best, only have 65% of the clamping force of an ARP stud, and consider that the combination of the firing load and inertia at RPM cause loading's that amount to thousands of pounds.

	The last few foot pounds of torque applied to a bolt only twists it up like a torsion bar, and does nothing to increase the clamping load, not to mention possibly damaging the threads in the block.
	The factory use bolts because they are cheaper and quicker to assemble, so best engineering practice is always to replace a bolt with a stud whenever possible.

What if all this is just too much hassle ?

For a race or performance engine we really recommend making the effort. For a regular rebuild, perhaps consider just fitting studs to the centre main where there isn't a clearance problem?
We can happily supply 1/3 of a kit! Part number MSA54


	‘A’ Series Main Stud Part Number recap… 850-1098 (small main) use #MSA44, 1098 large main & Cooper S use #MSA33, for all other 1275 use #MSA54, for the 2 extra studs for a steel centre main use #MCS-1, all of the above have 12 point nuts & hardened washers.

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