18 replies to this topic

[Java_Green]

Match the compression to the cam and rocker combination. Most people use too much static compression. Road cams with smooth idles up to 9.5 to 9.75:1. Cams with lope to the idle 10:1 max. 280 duration cams 10.5:1 max. All using E5 97+ octane fuel.

Ac

So what are the CR figures for E10 RON95 and are figures based on roughly the same dynamic CR figure?

[Java_Green]

Match the compression to the cam and rocker combination. Most people use too much static compression. Road cams with smooth idles up to 9.5 to 9.75:1. Cams with lope to the idle 10:1 max. 280 duration cams 10.5:1 max. All using E5 97+ octane fuel.

Ac

So what are the CR figures for E10 RON95 and are figures based on roughly the same dynamic CR figure?

[Jonnym71]

I think I’ll keep an eye out for a different head with larger chambers and keep the other as a ‘just in case’ spare. It’s the easier option and less risky.

[Jonnym71]

I’ve managed to source a head with 36/30 valves and nicely ported. It’s got a much better cc, so this is the planned spec:

1275cc
Above head
Mini spares evolution001 cam
Migh comp MG Metro pistons
MG Metro dizzy
Duplex vernier
Either 1.75 SU or twin 1.25 SUs

Hoping for 80+ BHP at the flywheel as a minimum.

3.44:1FD with 6x10 revolutions and 165/70x10 tyres (yet to be bought)


The plan is to get it running and drivable - will be rolling road tuned and then when funds allow probably add to the spec of the engine and add straight cut drops/gears. Yes, I’ve owned a car with a straight cut box (Quaiffe) and you’re happy with the noise.