Couple of tech questions.

[RobThomas]

1. Using the 'Tank' cylinderhead, the B6HS short plugs seem too short and the long reach plugs seem too long. How far does the plug nose normally protrude?
2. Valve guide lengths changed between USHM2 and USHM3. How do you know which type you get when you buy new ones? Are they all ex-Army stock?
3. Can the rope seal for the sump be bought separately? I've got 2 new gasket sets and both have ropes that are too short. Duh!
4. Did the Tank engine run high or low compression? Down to head chamber space, I guess.
5. Was the camshaft the same throughout '8' production? Likewise valve springs etc.


Over to the Anoraks.

[mike.perry]

Hi Rob,
The parts book lists 2 part nos for guides, inlet X15167, exhaust X31635. It does not list any change of part nos. Further on it lists the same part no for inlet and exhaust valves, X15048 but then lists a different exhaust valve no, 168026 at engine no 106266.
Springs X15608
The generator parts list gives X31635 for inlet and exhaust guides and X168078 for both valves
The generator used military spec radio suppressed distributor, HT leads and spark plugs of a completely different design, the head was however the same as the Mk2 Vedette except that the Vedette used 18mm D10 plugs.
Camshaft - generator and Morris 8 = X15461, MM = X30103.
You should have a long and a short piece of rope oil seal, I probably have some spares.
There is very little difference between HC 6.7:1 and LC 6.5:1, not much more than production tolerence.
I hope that helps or confuses!

[RobThomas]

Thanks Mike.

Hmmm. Morris 8 is listed as 5.8:1 and srsE as 6.5:1, 23.5hp and 28.5hp respectively. The Tank genny head is the same as the Morris 8 and they all seem to have the same stroke and flat topped pistons. Perhaps the Tank head has larger chambers and thus runs the lower power output?

8 guides are X15167, E changed exhaust to X15866 but Z was the same until engine163452 when they all became X31635. I'm guessing that this is a minor change such as removing the screwdriver slot for grinding in the valves.

I've just pulled apart an engine from a Morris 8 (1935) which has a srsE engine number, an oil pump like a srsMM, a -40 thou counterbalanced crank and sleeved bores back to STD (+.0005 inch?). I was hoping to find out what the origins of the engine are and what would be the best configuration to go for to get best performance out of it.

I'll try to measure head chamber space on some of these heads tonight.

[mike.perry]

The top hose is different on the generator engine head
Camshafts all appear to have the same timing, 8 52 52 20
My book gives power output as 23.5 @3900 for 8 and 29.6 @4400 for 8E. Seems high when MM is 27.5 @4400.
Counterbalanced crank + shell bearings = E engine
Non counterbalanced crank + shell bearings = Z van engine
White metal bearings = 8 engine
Do you have Morris Register Morris 8 Information Manual?

[RobThomas]

Sommmmmmmewhere, yes. We did the big house move after christmas and I've mislaid a lot of bits.

I've ended up using an E head which looks like it will still reach the top inlet to the rad but I'll need to fabricate a side water union to clear the pre war steering box on this car. I must have 3 dozen head studs, all either too short or too long. Typical! I've just started the job of grafting an MGPA remote assembly onto the Morris 8 srs1 gearbox.

M8, M8E, Tank and MM all seem to have the same chamber size in the head. Any idea what the CORRECT torque setting is for the head studs? 44lbft, but dry or oiled? I know it has been debated a bit in the past.

Thanks.

[RobThomas]

Here is the engine I'm putting in the 1932 Minor. Nearly finished.

I got a bit carried away with the polishing, again. I'm amazed I didn't sucker myself into polishing the sump![frame][/frame]

[RobThomas]

Aha! Morris 8 pistons are 60mm high and E/MM are 63.5mm, according to an old manual. Higher comp ration due to piston height.

[mike.perry]

The important dimension is from the gudgeon pin to piston crown.