Morris Minor Owners Club

Hi
I am rebuilding a 1275 midget engine, fitted with a 12G940 head.
After fitting the head, I found I did not have an oil supply to the rocker shaft.

Removed head found oil drilling in head blocked.

I could not clear it, and tried to remove the brass plug, in the cross drilling.
This had to be drilled out.
Noticed then, the brass plug appeared to blank off the cross drilling from the block.

Can anyone explain this, had the plug been knocked in too far, or a oil metering, which was blocked.

I am going to tap it 5/16" UNF to plug it off

Regards Win

Well spotted that there was no feed - could have been nasty! Your fix should be fine.......

Hello Win,

5/16" sounds too big, from memory the plug is in the order of 1\8" to 3\16" diameter, and is quite close to the head face. ?

Alec

Have you any pics? I can't quite picture what you have described. I'm interested because I have also fitted a later 12g940 head, but to an early Marina block. And I think one of the rocker mounts had a hole in it.. But no hole underneath the mount, through the head.
Is this what you are referring to?

The rocker post with the hole drilled in it changed position between 1098 and 1275, IIRC. Only one post is drilled so you might need to change the 1st and 2nd posts over to get oil feed. (The heads from Pierce don't have ANY direct drillings and rely on oil leaking past the rocker stud to lubricate the head. )

BMC?

As to the plug going in too deep....it is the same on Mexican VW engine blocks. There is a plug which is often found to be stuffed too far into the hole.

Hi
The brass plug which I drilled out was 1/4".
Sorry no pics, its all back together.
The hole is in the front pedestal, to line up with a hole in the head, the oil is then transferred to the hollow rocker shaft, then feeding each rocker, just check you have a oil to the rockers.

Regards Win

Yes - the oil does need to feed up through the hole in the rocker pedestal from the matching hole in the head - it changed a long time ago - not sure when, but long before the 1275 IRC. Was done to move the 'fixing' screw/plug for the rocker shaft away from the end post location where it had been causing problems weakening the shaft.....

Here's a photo showing the holes in question
Regards
Declan

[frame][/frame][frame][frame][/frame]

Hello BMCE,

"Was done to move the 'fixing' screw/plug for the rocker shaft away from the end post location where it had been causing problems weakening the shaft....."

I seem to remember that number four pedestal had the oil feed but Declan's shows number one, so still at the end of the rocker shaft?

Alec

Yes - the oil feed has never moved - just the 'fixing' screw, which used to be in the pillar with the oil feed - but was moved along on later shafts. Hence - if owners moved the pillar with the screw, they starved the rocker shaft of oil.