Valve lifter

[paulelana]

I have all the parts to fit a valve lifter to a 250 engine but when I offer up the valve cover to the head with the lifter attached it will not tighten down without operating the valve. This is because the lifter pin is already pushing on the rocker (screw adjust) and opening the valve. I have searched the forums and seen Nigel has said there are two pin lengths and I wonder if I have the wrong length or whether I am missing something else. With 5mm of washers on the outside I get clearance but the nut inside does not have all the threads engaged so I am not comfortable with that.

The pin is 7mm long past the circlip and at the moment I am thinking of taking approximately 3mm off and seeing if that works and having less washers outside. Before that I though I'd see if anybody has any other advice (but not about whether or not to fit a lifter to a 250). Many thanks.

[Duccout]

Hi,

I do not know the difference, but it would make sense that the pin that bears on the valve may be shorter for the heads with threaded adjuster type rockers. The problem is that the parts books are not very comprehensive and if there is a difference then it may not be listed. Eldert may know if he is lurking, as may Nigel, but he has not posted on here for a while.


Cheers,

Colin

[paulelana]

Thanks, it is good to know I’m thinking along the right lines,

[themoudie]

Aye Paul,

Nigel has a Facebook account and appears to be posting regularly there. He also has his direct contact details published there. Might I suggest an email requesting guidance, with brief details about your problem? I have always found Nigel very obliging.

Here is his email address: info@bevelsingleparts.com

Good health, BillR

[themoudie]

Aye Paul, further to my earlier post and PM, here are some images of the valve lifter fitted to a 1975 350 MKIII engine assembled (!) by MotoTrans.

This engine was originally fitted with the screw and ball rocker arms. You should note that the circlip fitted to the end of the valve lifter plunger is missing and the stroke of the valve lifter plunger is limited by the use of a threaded rod through the front hole of the valve lifter mechanism casting, preventing the full stroke being used. The plunger emerges by 4.8mm from within the lifter body using this setup.

Images 1 and 2 show the offside (RHS) and nearside (LHS) of the external parts of the valve lifter mechanism.

Image 3 shows the lifter in the clear position and image 4 shows the lifter position when depressed to the maximum possible, with the limiting threaded rod in place.

Whether this is as the lifter was assembled at the factory, or not, I do not know? It is as I found it.

Good health, BillR

[paulelana]

Very interesting pictures. I wondered why there was a hole with nothing in it on the arm as that seemed odd from an engineering point of view. The other thing that is obvious is that the length of the pin past the circling groove is definitely shorter than mine. I’ll take a look at mine this afternoon and see what it all means. Huge thanks.

[Roland]

some bolt fits and limits the lift perfect.
(not present here)