The Dark Wob

Not being a harbinger of doom but you may need super unleaded or even the odd gallon of 100LL aviation fuel to get the best from a dizzy designed to run high compression and 5 star fuel.

Isn't modern super unleaded loosely similar to the octane rating of 4 star? I seem to remember reading it in a BL workshop manual somewhere.

Also I believe 100LL contains way more lead in it than 5 star. Low Lead being low for aero engines. I know many people run old car engines on it though, but no idea of the legality of it nowadays. You can still buy leaded fuel, but not sure how the tax works on 100LL and if its like Red Diesel?

The high compression ratio (this engine) is 8.0:1 so even with the head skimmed it will run fine on standard 95 RON.

With Conrad's assistance I procured another 1100 engine for the Morris. The idea being to get this up and running, see how it goes, if it seems to work OK swap engines and overhaul the worn unit in the car.


Whilst I really have umpteen other more important jobs to do, when we turned the flywheel it nearly completed a full revolution before jamming up. My motor functions were rapidly failing in the cold (talking about my hands here, the vehicle's motors have already failed), precluding any further work on the Snipe, so with this Moggy engine readily accessible curiosity got the better of me and I took the cylinder head off.


Apart from the general dirt and grime from standing the first fault was pretty obvious.


I raided one of my old 803cc heads for a replacement clip. At least I didn't throw them away, though I had been trying to get rid.


The head did not really put up much of a battle, a few blows with a hide mallet broke the joint.


The bores were much better than I expected with no ridge at the top, but these two grooves in Number 1 require further investigation. Broken piston ring perhaps?


With the cylinder head being pulled up the pushrods came with it so I had to pull them down out of the head again. As I expected, some of the cam followers had been pulled out, but I was going to remove the tappet chest covers anyway.


Also to be expected, as we both surmised, a valve or two was stuck open due to the length of time it had been standing.


So, curiosity satisfied I made a holder for the pushrods to keep them in order and put the cylinder head back on and everything else back together for another day. It has to be stripped down and everything cleaned up as a bare minimum. I wonder where the other half of that valve cotter clip went to - it could be floating about in the sump.

I finally got around to some serious dismantling of the Snipe's engine to remove the cylinder head. The exhaust manifold is simplicity itself to take off; the hardest part is undoing the lower of the two exhaust pipe fastenings. The distributor did look quite clean to me and when I removed it saw the model number written in felt tip pen. So this was clearly a recent addition, I have no idea who fitted it or why, unless it had something to do with the electronic ignition kit, although you don't need a replacement dizzy for that.

So you can see it's definitely wrong for this engine, and the wide range of models for various engine configurations.


I removed the petrol pipe, a nice steel tube from the pump to the carb, the coolant temperature sender unit wire and now all that's left to do is remove the inlet manifold, again a straightforward task.

I wonder if the dizzy was fitted to reduce pinking on crap modern fuels, as I recall you saying it had less advance? would this have run on 5star when new?

8:1 compression ratio it would run on paraffin when it was warm without pinking!

I thought not, but figured I'd ask.

To be honest I had exactly the same thought until the squire dismissed my worries by knowing the "high" compression was just for the time.

Yes indeed, though I still can't summon up the courage to try and start it on the handle.