Rocker problem

[lee_rob]

So I was advised by two different mg engine guys not to grind the heads off the clamp bolts as it weakens them and could mean the rocker fingers work loose. So I have given in and bought a new J type aluminium rocker cover. It looks quite nice actually just hope the light car section doesn't drown upon it and start suspecting the engine is a J type lol

[Ian Grace]

I won't tell them if you don't!

[ian judd]

Ian's posting about the correct location of the eccentric bush intrigued me. Although it is correct I couldn't see why the oil should be cut off. This afternoon I got out a box of rockers and discovered that there are two types - one where the groove is interrupted ( and a small hole, purpose unknown ) and another type where the groove continues all the way round. With this type - later?- the oil will get round wherever the bush is. The one with the gap would certainly cut the oil off if in the wrong position. I only have a couple of this type, most of mine having the groove going all the way round which suggests they are a later and more common.

[Ian Grace]

Here's Ian's rockers. You can see that the one on the right has the oil groove running right around the inside, whereas the one on the left only has a partial groove. All very interesting. One wonders why they weren't all made like the one on the right from the outset.

[lee_rob]

The ones on the left are what were on my minor when I replaced them, they have a drain hole in the bottom of them which I can only assume is to allow some oil to come out and pass down into the cylinder head.

[halbe]

I also have the left ones, the hole you can see was made when the oil passage to the camshaft was drilled. It is closed of when the eccentric bush is fitted.
I don't think one would want a drianhole as i would like to keep the oil going to the camshaft where it's needed most.

Regards,
Halbe

[Ian Grace]

So I'm working through the first ten years of Magazines, preparing them for the Anniversary CD. It is a monumental task to get all of the page and article Word flies assembled into single files so they can be .pdf'd cleanly. It is an amazing experience to go through them all, page by page, in detail, and see just how much stuff there is - over 1,400 pages of our history!

And while working through M 111 - the Spring 2003 issue - I found this:

"While on the subject of rocker fingers, your Editor recently had two sets rocker fingers reprofiled in New Zealand, courtesy of Jack Blyth. On close inspection, there appears to be two distinct rocker finger variants. One variant (left) has an incomplete inner oil groove with a drain hole drilled through the back of the rocker, while the other variant (right) has a complete annular groove but no drain hole. Can anyone throw any light on the reason why there are two variants? Did one succeed the other perhaps? Needless to say, the Morris Spare Parts List simply quotes the single part number - 35054.

[Simon]

Yes. The rocker with full inside grove has had the hole plugged after the oilway through the rocker to the part that rubs against the cam has been drilled. With the rocker with the partial inside grove the oilway drilling has not been plugged as there was no need to do so as little oil will have found its way out if the hexagon eccentric brass bush has been installed facing the correct way. I think.

[Ian Grace]

Interesting topic - I guess we'll never know when the change was made, but I'll be checking my fingers in future when I build a head! In fact, it should be easy to identify early/late fingers even on an assembled head by simply looking for that hole at the back end of the fingers with the cam cover off. I'll take a look at my fabric saloon tonight - I would expect to see holes as it is an early car with its original engine.

[Ian Grace]

Yup - all got holes in.