GBW

I asked what they were not what they are called! There is a "something" that accesses the oil pump shaft. It is a stud with a hollow needle on the end. No sign of a strainer and I can see no reference on the (ASAP) manual or the MG manual.

I am an intruder out of curiosity! What are those please?

The original engine, supplied by Norris and sons, had the deepest part of the sump at the rear. This is as fitted to road engines (so that the shallow part cleared the front suspension). I thought nothing of this and the shaft angle is quite acceptable. However, the engine I bought off ebay, had the sump at the forward end. I eventually realised this was to allow the engine to be lower when fitted as a marine version. This meant that the oil pickup strainer was remote from the oil pump. The feed to the pump was extended to suit. Both the modified pump feed and the pickup strained are professionally manufactured. The ebay sump was in a poor condition and my efforts to weld up the leak fruitless. However, I found a brand new sump on ebay. The two varieties are not reversible.

When I acquired my spare engine, I had a problem with matching the oil pump to the strainer. (You experts will all be aware that the sump is the opposite way round to that on the road engine). I was able to obtain a pick up strainer from the MG owners club who stock many engine components from a complete engine downwards. It is important to remember though, that these engines are petrol and some components are different to the diesel version. https://www.mgownersclub.co.uk/spares

Just to make it clear, I am rebuilding a replacement engine and, while it is on the bench (actually on a fork lift so I can wind it up and down for comfort!) access is "rather better" than in the engine bay on the boat! My questions relate to preparing for the changeover. The existing engine is in the boat currently locked down and physically locked away until Monday next (Barry Island). She is on the hard and I am not really interested in diagnosing and fixing. With the replacement engine accessible all round and capable of being run in a controlled fashion, I am looking forward to being able to achieve correct timing and fiddling although I cannot impose a load except an electrical one.

Yes - it was prime suspect.

The boat is a sea going sailor (although she spent a year on a canal!). Cooling is sea water through a heat exchanger.

Thanks for the responses. On my cylinder head, the head end tapping seems "most likely" to be 5/8" UNF. A 5/8" UNF tap threads in without cutting but my plug gauge would not. I then discovered that was left hand! I understand from the DS steer, that there is confusion about this thread and not all engines may be the same. The temperature sensing tapping is also 5/8" UNF. The engine was bought on ebay dismantled as I am not happy with the power output from the existing one whose compression ratio leaves something to be desired. The bores on the ebay purchase were well over top rebored limit, so it has been sleeved and rebored, new pistons, crank regrind etc. As stated, I did take a feed from the temperature sensing fitting point and the hoses were warm but only warm. The return was teed into the heat exchanger return. It will be reassuring to run the replacement in the workshop and prove timing etc where it is convenient. Thanks again.

I introduced a engine water take-off before the thermostat but it seems to be ineffective. Where do others connect please?