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Changing rockers in situ

Posted: Mon Mar 04, 2024 8:34 am
by Sleeper
Dear All

Wanting to fit a 1.3 : 1 rocker set-up with pedestals etc ...

Is it possible/acceptable to change the rockers/shaft/pedastals with the engine in situ without replacing the head gasket ?

ie. head bolt re-torqueing?

Thinking of releasing the rockers,withdrawing the rocker shaft , replacing one pedestal at a time then refit shaft/rockers etc.

Thanks

John ;-)

Re: Changing rockers in situ

Posted: Mon Mar 04, 2024 8:52 am
by svenedin
I don't know the answer to this because I did the rockers at the same time as the head gasket. It is not much more work to do the head gasket and you get to inspect the cylinder bores and valve/valve seats at the same time. The actual head gasket (copper) is not expensive and you will then know it is all good.

There is an uprated rocker shaft available that has a thicker wall than the original. One thing to be careful about is ensuring that the oil passage in the base of the rocker pedestal lines up with the oil passage in the cylinder head. Some of the pedestals do not have the oil passage so if you get them in the wrong order there's no oil getting to the rocker shaft. Also I am sure I have seen later pedestals that do not have the oil passage in quite the right place.

You might also want to inspect the valve stem oil seals with the head off and perhaps do a light de-coke if you need to. Definitely replace the bypass hose if you have the head off.

Stephen

Re: Changing rockers in situ

Posted: Mon Mar 04, 2024 9:01 am
by philthehill
You cannot replace the pedestals without disturbing the head gasket contact even if you replace one pedestal at a time.
The risk of the head gasket subsequently failing outweighs the additional work of replacing the head gasket as part of the installation of the 1.3 - 1 rockers.

Re: Changing rockers in situ

Posted: Mon Mar 04, 2024 3:25 pm
by Sleeper
Phil

Many thanks for that , was thinking that way , will shelve it for now until head-off time... may even prepare a " worked-on " head for the transplant...

John ;-)

Re: Changing rockers in situ

Posted: Mon Mar 04, 2024 4:28 pm
by philthehill
When you refit the head shorten the rocker locating pin lock plate so that the locking pin is secured only by the 5/16" stud. Then only the 5/16" stud has to be disturbed.
BMC/BL did a similar thing but mistakenly shortened the locking plate the wrong way so that the 3/8" head stud had to be undone. :roll:
https://www.morrisminorspares.com/engin ... 59-p830386
With the shortened locking plate - when removed - the rocker shaft and rockers can be dismantled and removed from the head without compromising the head gasket.

Re: Changing rockers in situ

Posted: Mon Mar 04, 2024 8:57 pm
by Sleeper
Will do, thank you...

John ;-)