16 replies to this topic

[Joe555]

When I calculated the compression ratio I made the mistake of not adding the combustion chamber to the total volume.  I think what I should have done is get low compression pistons, because everything else is the same as it’s been for years.  I have half a tank of unleaded fuel in at the moment and am waiting for the Castrol Valve master plus to arrive.  I have set the ignition timing to 8 degrees BTDC and it idles very smoothly at 1000rpm and drives well, I haven’t gone above 3000 rpm I will check the plugs when I have done a few miles on a tank full of Shell V-Power and octane booster. I have looked in my Haynes Metro manual and found some engines had 10.5:1 compression ratios, but maybe fuel was better then.  Has anyone got any tips on running in.

[carbon]

Would suggest filling the top half of the tank with 99 octane, such as Shell V-Power. Addition of Castrol Valvemaster Plus at recommended dose will give another octane.

 

You're right, the MG Metro ran 10.5:1 but that was in the days of 4 star leaded fuel, 98 octane. And although the MG Metro had a 'sportier' cam profile, this did not have as much lift as the SW5, plus you have1.5 rockers. So your motor should be giving significantly better torque than the MG Metro, as long as you can get the mixture and ignition timing optimised.