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850 Rocker Shaft

Posted: Sat Nov 01, 2014 3:20 pm
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

Re: 850 Rocker Shaft

Posted: Sat Nov 01, 2014 3:57 pm
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

Re: 850 Rocker Shaft

Posted: Sat Nov 01, 2014 4:23 pm
by Macker2
Oh, not as painful as I thought. Cheers Nick.

Re: 850 Rocker Shaft

Posted: Sat Nov 01, 2014 9:16 pm
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.

Re: 850 Rocker Shaft

Posted: Sat Nov 01, 2014 9:27 pm
by Vegard
No matter where you drill, bin the aluminium rocker posts.
Seriously!!

Re: 850 Rocker Shaft

Posted: Sat Nov 01, 2014 11:57 pm
by Spider
Vegard wrote:No matter where you drill, bin the aluminium rocker posts.
Seriously!!
+1. What were they thinking???? Blown head gaskets perhaps.....

Re: 850 Rocker Shaft

Posted: Wed Nov 05, 2014 8:09 pm
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

Re: 850 Rocker Shaft

Posted: Thu Nov 06, 2014 12:19 am
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.

Re: 850 Rocker Shaft

Posted: Thu Nov 06, 2014 12:39 am
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.

Re: 850 Rocker Shaft

Posted: Thu Nov 06, 2014 11:12 am
by Macker2
Aaah now I see, I will get some from mini spares,

Thanks
Macker