How easy does the engine start, as this would indicate if the piston rings are worn, thus causing the oil loss.

Other options are worn valve guides.

Could also be glazed up cylinder bores due to incorrect oil grade or long periods of engine idling.

Has the oil consumption suddenly started or has it been doing this for a while? If as you suggest this has recently started, the least cost option to start with is to change the oil [and filter if your feeling generous] to a suitable grade and give it an 'Italian tune up' i.e a good thrashing. This should improve the situation if the bores are glazed up.

Let us know your findings and report back.

^ Update, I looked out the PC con rod yesterday.
Its in good condition, and even comes with fair condition STD piston and rings. Piston rings may be good to go again if carefully cleaned up, as I tried them in a Petter AC1 cylinder barrel (also 3" bore) and the ring gaps looked acceptable.

The con rod also has a set of big end shells which are also in reasonable condition. Only problem is they are -0.010" undersize. Let me know if your interested via PM.

If the cylinder liners are tight in the block then why not skim the tops off the cylinder block to correct the problem, then either:

Use more bumping clearance shims to compensate for the material removed, or

Remove a corresponding amount from the tops of the pistons.

If your still interested I have some BACo (British Alumium Company) pistons available in +020 and +060 oversizes that I would be prepared to sell.

If your still looking for a camshaft, here is what seems to be a good used example:

https://www.ebay.co.uk/itm/144422521423

Posted in error

I can see the image:

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=133970436456&_sacat=0

Yes from the picture, that looks to be what to be what your looking for.

However, be aware of the following:

1) Ensure the direction of rotation of the starter motor is correct, as Lister's definition of direction of rotation has caught many people over the years (NOTE! If your engine serial number has SR2A, the A indicates anti clockwise rotation)

2), You will need a spacer to go between the starter motor and bell housing, like so:

      https://www.ebay.co.uk/itm/265239226729?hash=item3dc17d6969:g:evoAAOSwdjVg-bIX

 This is for the HA series that use the Lucas CA45 starter motor, but the general shape is very similar to the SR engine.

3), Finaly confirm that the number of teeth on the bendix is correct.

If you are still looking for a an jector for your PC1 engine, here is one on ebay UK at present:

https://www.ebay.co.uk/itm/284564971770