S rocker pillar to valve spring clearance

[Peter1071]

I've finally got round to replacing my rocker shaft on a 1275 S engine. When I put it together 20 years ago I mistakenly used a set of 2A534 rockers and sintered steel pillars. I now have S pillars and rockers, which have been re-conditioned very nicely by Oz,but have found that there isn't clearance between a couple of the pillars and valve springs. Looking at another set of S steel pillars I have, there are marks where valve springs have fretted against them.Is this a common problem? Is it best to grind a bit off of the pillar or should I swap for the sintered steel pillars which appear to have a better shape to clear the springs? The head is AEG163.
Thanks for any advice you can give me,

Peter

[Herbert]

I would definitely use the old ones.

[bwaminispeed]

Several things you can do, easiest is to grind a flat on the pillar to clear the springs......

You can drill the holes slightly larger, and, shift the pillars over slightly.....

Or (best, but, most work), you can make new pillars with the holes drilled offset to move them over......this method also helps with the offset spacing of the rockers themselves....

I have used all 3 methods over the years with no problems or issues........

[Peter1071]

This is an S steel rocker with wear marks from the valve spring or, more likely, grinding marks to clear the valve spring. The other photo shows the sintered steel pillar which has flats machined for clearance.

[croc7]

If I'm not mistaken, aren't the pillars in your picture installed backwards? Shouldn't the rounded end be installed between the pushrods and the 'pointed' (chamfered) end of the pillars be installed to be situated between the valve springs??

[Nick W]

If I'm not mistaken, aren't the pillars in your picture installed backwards? Shouldn't the rounded end be installed between the pushrods and the 'pointed' (chamfered) end of the pillars be installed to be situated between the valve springs??
[/quote

Dont think thats possible as the hole in the pillar are different sizes

[Dearg1275]

Before sintered pillars were introduced, what would you have done? Slice it off the pillar. What do you loose by doing that? You still have the correct, very strong, un-bustable S pillars. The originality police will have little to complain about.

D

[croc7]

If I'm not mistaken, aren't the pillars in your picture installed backwards? Shouldn't the rounded end be installed between the pushrods and the 'pointed' (chamfered) end of the pillars be installed to be situated between the valve springs??
[/quote

Dont think thats possible as the hole in the pillar are different sizes

I know that but something is wrong here. Admittedly, the last Cooper S (‘67 Morris) that I owned was several years ago but I don’t remember pillar to valve spring clearance by interference as a design feature. Am I wrong? Is that the way the early 1275 Cooper S valve trains were?

[Dearg1275]

If I'm not mistaken, aren't the pillars in your picture installed backwards? Shouldn't the rounded end be installed between the pushrods and the 'pointed' (chamfered) end of the pillars be installed to be situated between the valve springs??
[/quote

Dont think thats possible as the hole in the pillar are different sizes

I know that but something is wrong here. Admittedly, the last Cooper S (‘67 Morris) that I owned was several years ago but I don’t remember pillar to valve spring clearance by interference as a design feature. Am I wrong? Is that the way the early 1275 Cooper S valve trains were?

The part number stamped in the pillar looks strange. Early Cooper part no we’re 12A210 & 12A211, S ones were AEG165 & AEG166. Neither bears any similarity to the stamping on view in the photo. Is there any other numbers on the pillar on the other side?

D

[Peter1071]

I think you've solved this! The numbers stamped are 12A210, 12A211. Checking AKD3509 you are right, I'd never come across these 997/998 rocker pillars before. Both sets of pillars I have came on shafts with S rockers from auto jumbles years ago so I'd assumed they were S pillars. One set has been machined down on the base quite a bit. I'll give these a wide berth and use the sintered steel pillars for now.

Many thanks for your help,

Peter

[bwaminispeed]

Don't forget, the 1275 heads and, 997/8 heads have different valve spacing's, the two end pairs being closer together on the small bore heads than the large bore ones......

This is probably the cause of the issue you are seeing.....

[Peter1071]

I'm just coming back to this to try to clarify what genuine mk1 Cooper S steel pillar looks like. My AKD3509 parts book states that for 997 and 998 cc Coopers the part number is 12A210, and 12A211. For the Cooper S the number is AEG165, AEG166. Was this number stamped into the S pillar to identify? Does anyone have a photo they can post of a genuine S pillar?
I have noticed that in David Vizard's old book, How to Modify Your Mini, the picture he has of an S pillar has the number 12A210/211 stamped into it. My conclusion, at the moment, is that the AEG165 S rockers are simply the 12A210 rocker posts with suitable flats machined from the front to clear the valve springs.

Can anyone help put this to bed?

Thanks,

Peter