Rocker Advice

[rocco]

I've had a chance to look at the rockers tonight but I cannot tell whether they're still serviceable or not. The shaft has what looks like a threaded screw in it and the adjusters have small oil holes. I don't know what is meant by "waist" though.

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[philthehill]

The rocker shaft in your photo above does need to be replaced as it is worn were the rockers move backwards and forwards.
The rocker is slightly worn but if careful a light hone should see most of the indent removed. Do not go too deep with the hone as the rocker tip is hardened to a shallow depth.
The threaded plug in the end of the rocker shaft (as I mentioned above) can be unscrewed to clean out the inside of the shaft.
Later shafts do not have the threaded plug just a mild steel bung in either end.
If you unscrew the adjustment screw fully from the rocker you will find that the adjustment screw has a waist (narrowing of the screw at its vertical centre. This is is to allow oil to circulate. The hole through the centre of the adjustment screw is to allow oil to get to the ball on the end of the adjustment screw and flow down the push rod to the cam follower.
Both the waist and the hole through the centre of the adjustment screw were found to be surplus as there was and is enough oil swilling around the rockers and cam followers to keep the adjustment screw ball and cam followers well lubricated. A side effect of the waist and oil hole was that there was a chance the adjustment screw could snap; so BMC did away with the waist and the oil hole and fitted instead non waisted, non oil hole adjustment screws.

[rocco]

Cheers Phil.
So new shaft (thicker one without the screw) and new adjusters without oil hole and waist are to be ordered. The ones I have now must be bloody old if they stopped making them, presumably in the mid to late 60s.

http://www.minispares.com/product/Class ... |Back%20to

Rather than the sintered rockers you shared a link to already and rather than grinding the ones I have, would you suggest getting a set of 4 of the ones in the link below?

http://www.minispares.com/product/Class ... |Back%20to

Does the thicker shaft allow me to use the same posts and just swap 1 and 2 over to locate it at the 2nd position or do I have to buy at least 1 new post as well? I'm so confused by it all. Wouldn't it just be easier and cheaper to buy a complete new rocker assembly?

[philthehill]

The rocker set up you have is old.
You should replace the rockers as a full set qty 8.
You can use the same posts but you may need to drill the post going to No: 1 position and countersink the bottom to allow the oil to flow to the rocker shaft.
Below is an original rocker pillar which has been factory drilled but the factory drilled countersink was shrouding the oil transfer hole in the head and had to be relieved towards the dark shading.

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Note:- I have found that on some rocker assys all shaft pillars have been drilled to allow oil to pass so you may be able to get away with just swopping the pillars.
You could replace the whole rocker assy but I doubt that it will end up cheaper.
https://www.morrisminorspares.com/engin ... s-p1238982
If you do replace the rocker adjustment screws make sure that you get the right size.

[rocco]

I must be a proper dumb-dumb because I cannot even get my head around the meaning of a pillar or a post, aren't they the same thing? What is meant by a pedestals then?

If I need 8 new rockers, a new shaft and adjusters then I may as well chuck in a new springs, spring washer and cotter pins. Even then I'm not convinced the posts or pillars or pedestals are going to be usable without drilling oil holes in them.

Sintered rockers, thicker shafts, waisted centres, second pillars, soft steel plugs, drilling oil holes, it's doing me in.

How about this one? Could I just buy and plonk this right on top and be done with it, even if it is a bit dearer?

https://www.minisport.com/1-3-1-mini-ro ... ckers.html

Thank you as always, you know I appreciate all the advice even if I struggle to make sense of it.

[philthehill]

Rocker shaft pillars, pedestals and posts are all the one and the same thing. Different people/firms use different terminology but all relate to the same item.
Fitting the rockers shown in the above link to me is a complete waste of money and would not be a good move as regards your engine. Only if you have the full modification works carried out on the head and fitted a better cam would the rockers in the link be worth while.
You could recondition your original rocker assy for a 10th of the cost of the rocker assy in the link above but it is your money.

[Mark Wilson]

I was advised four or five years ago by a staff member at Minispares that the "Cooper S" rockers linked to earlier were of dubious quality and that he personally felt they should not be selling them. They may have addressed the quality problem since then, but the advert looks the same.

[svenedin]

MMOC spares still want a cheque sent by post……I will really have to search hard to find my cheque book. I haven’t written a cheque in years!

[rocco]

I just looked at the rocker on my "new" car because the securing bolt rubbers have completely perished. I will have to clean it up anyway so I thought I'd remove it and have a look to see if any of the rubber had fallen inside.

I noticed that the pads on the arms are unlike the other rockers I've got. There seems to be different metal there, like the contact pads are removable. I can't find any similar images except for at this site >> https://racingnorton.co.uk/SOHC-Rocker-Arm-Rocker-Pads

I bet Phil knows something about them.

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[svenedin]

They look like standard "pressed" type rockers to me. As far as I know, the pads that contact the valves are not removable. It is confusing because there are a number of different rockers used over the years. See this post for more information: viewtopic.php?t=77334

These are from my car:

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[philthehill]

rocco
The rockers fitted to your car are the standard 'A' Series pressed steel type.
The anvil at the tip of the rocker is not replaceable.
All you can do is hope that the anvil faces are not hollow.
The anvil is case hardened and if excessive cleaning up of the anvil is undertaken it is possible to break through the case hardening and you are left with normal metal which will not stand up to and long term use.
The anvil face has to be ground so as to give a rounded face in line with the rocker so that the movement action across the tip of the valve is smooth.
The 'A' Plus sintered rockers are a good replacement for worn rockers. They are available new.
Unless you want to spend serious money aftermarket rockers are not worth the money.
Having tried poly rocker cover bushes and found them failing I would use the ex factory rubber bushes in this application.

If you have tappet adjusting screws with a hole down their centre they should be ditched and the later solid screws fitted.
The screws are waisted and it is not unknown for the adjusting screw to break at the waist and then damage the engine. BMC replaced the hollow screws with the solid screws because of the frequency of breakage. Oil circulation is not effected by fitting solid adjusting screws.

[rocco]

Thank you so much for the advice guys. I would have sworn by the different colour metal and what looks like a thread inside the middle of the arm that the pads are threaded in. Looks completely the different to the other two rockers I have.

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[philthehill]

The rockers in the top photo are the sintered type and can be used on the Minor 'A' Series. The rockers in the second and third photos are the forged type and were used on the early 'A' Series engine.
Both sintered and forged rockers are suitable for the 'A' Series.

[rocco]

So we have sintered, forged and pressed types to choose from. I think I'll stick with what's already there then, all things being equal.

I already bought new adjusting screws without the waist and oil holes - for the other car.