850 Rocker Shaft

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Macker2
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850 Rocker Shaft

Post by Macker2 »

I'm guessing that I need to do some drilling somewhere here. The oil hole on the new shaft is on a different pillar but there is only one hole in the head ?
Can anyone put me on the right track.
Thanks
Macker
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Re: 850 Rocker Shaft

Post by 'S'-type »

As the tapered location screw of the new shaft is lined up with number 2 rocker pillar instead of number 1, those two pillars have to be swapped for each other. So the old number 2 has to have an oilway drilled. (1/8” drill). The hole in number one can be used to line up the new one. It is advisable to put a good sized chamfer at the bottom to allow for any misalignment. It’s covered on page 81 of Vizard’s ‘How to modify your Mini’

Nick
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Macker2
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Re: 850 Rocker Shaft

Post by Macker2 »

Oh, not as painful as I thought. Cheers Nick.
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Re: 850 Rocker Shaft

Post by ivor badger 2 »

Early A series up to the late 60s, had the locking screw and oil feed in the no 1 pillar. They then changed to the strengthened shaft, with the oil feed still in no 1 pillar, but the locking screw in no 2 pillar. So if you fit a new (later) shaft to an early engine, it doesn't fit without modification.
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Re: 850 Rocker Shaft

Post by Vegard »

No matter where you drill, bin the aluminium rocker posts.
Seriously!!
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Spider
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Re: 850 Rocker Shaft

Post by Spider »

Vegard wrote:No matter where you drill, bin the aluminium rocker posts.
Seriously!!
+1. What were they thinking???? Blown head gaskets perhaps.....
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Macker2
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Re: 850 Rocker Shaft

Post by Macker2 »

Sorry if I appear a bit thick, but what would be the advantages of replacing the rocker posts for steel :oops:

Cheers Macker
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Re: 850 Rocker Shaft

Post by 'S'-type »

Early (non-S) engines had cast aluminium pillars which were prone to deformation under pressure. Metal fatigue! Replace with sintered-steel variety (standard from about 1968). S ones, being cast steel were/are the best as usual, but probably a luxury.

So if your motor is post 60s you should be OK to use the ones you've got.
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Re: 850 Rocker Shaft

Post by Spider »

Just to expand a little on S-types post, the problem with them is that the 4 rear Head Studs run through them and the Head Stud Nuts (try) to tighten against them, after a short period of time, some compression on the head gasket gets lost as the pillars compress.
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Macker2
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Re: 850 Rocker Shaft

Post by Macker2 »

Aaah now I see, I will get some from mini spares,

Thanks
Macker
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