I have to agree with Peter. I wouldn't drive it until you find the cause of the overheating and if it was me I would have the engine and gearbox out and confirm that the fan is operating correctly and that all the bits that Peter suggested are clear and not full of gunge.

When I saw the picture of the spark plug leads, I have to admit an expletive was the first thing that came out of my mouth.

Also I would fear for the future of the plastic in-line fuel filter that you have fitted with that amount of heat being generated and that will only end in serious tears.

Yep, pull it out, have a look when it is dirty to see if there is anything obvious, clean it up to within an inch of its life and have another look. Tell us what you find as you find it and we will advise as we can. Scrub the engine bay, replace the consumables and put it all back in.

It is back breaking doing lots of work on the engine when it is in the car.

Joe R

Hi Chaps. Thought I'd give an update on this as well as ask the inevitable questions. I have the Haynes book of lies for the 500, but I seem to trip over the 650 engine.

I had a further two elbows grafted onto my right arm and managed to get all of the bolts out of the thermostat plenum cover and move it out of the way a little without dropping the engine. The thing that stopped me removing it fully was the distributor - this is a 650 engine and it seems that they don't come in two parts as with the 500 - I didn't want to remove it so used a torch and mirror and with an extra 6 vertebrae added to my neck I could see that the fins were pretty clear. I refitted the plenum making sure all of the joints sealed propely.

I may have found the problem though. Where the rear exhaust pipe meets the manifold one of the bolts was loose and the other was completely missing. Not obvious when the engine was turned off as the joint looked good. With it running at more than idle hot gasses were escaping. I added some firegum and replaced the bolts.

Still testing it, and the enigine will have to come out over the winter anyway, but to the inevitable questions

Replaced the HT leads Then re-did the timing, idle and mixture. Set 10% advance at idle but it jitters +/- 1%. The jitter is regular almost as if each cylinder is firing differently. The only things I can think of ares the cap, rotor arm, distributor cam, plug gaps? Everything else should be commion to both cylinders - I ran out of time to take it all to bits again and diagnose, but is there a known problem?

The sump was used on the Somme I think! The cooling plate has been bashed so there are no air channels left. Looking at it I can't see how the sump can be changed without the air ducting covers coming off the left hand side, or did I miss something?

Lastly, the air flow increases as the revs rise (which indicates the fan working properly) and the covers above the spark plugs (which I was missing) make a big difference to airflow at the flap. There is however an open hole in the middle of the vertical LHS ducting, about 1/2" diameter which looks manufactured. I'd like to blank it off, but is there a reason for it being there? I can't feel a corresponding one in the rear ducting (but perhaps I need that fourth elbow

Lastly, what are the pitfalls of just lifting the distributor out (apart from having to re-time)

Thanks in advance (10% at idel)

John