Agreed David, I meant that I had too much timing and ran the motor too lean(secondary settings I kept from running the 32\36), so with the 12.5:1 compression it was getting it had no chance of holding inside the monotorque gasket. The other factor I don't really know is the cam duration, but meh.

Vacuum advance won't cause a head gasket to pop. And it turns itself off on moderate or heavy throttle. Removing it simply looses spark advance at low throttle settings.

It will run fine with vacuum advance disconnected.

I don't I ran the vacume advance on that run either, ditched it after I popped the head gasket running in the JTS head... it didn't stand a chance on those settings it had

Yes, too much mechanical advance will limit how high the A-series can rev.

http://youtube.com/v/prX72uER9Q8

Maybe I should of pulled some timing out for that run.

Nice work.

* 14:1 air/fuel ratio is slightly rich
* 14.7:1 is stoich (theoretical perfect mixture)
* 15:1 is lean, for cruising fuel economy

Max power is made around 12:1 to 13:1, which is why the stock Hitachi and Weber have a Power Valve for full-throttle acceleration. Normally do 14.7:1 for emissions (or 14:1 for smoothest running) but go extra-rich on full throttle.

Dyno run I did last year, the fueling was much too lean, pushing 14:1 air:fuel so I'm keen to get back there and see what the current jets will do

94.4hp atw

A14
+60 thou
H75 head (unported)
Bpro rocker shaft collars
small dish high comp pistons (1mm vs 5mm)
Lemonheads' nice crank
Weber 38\38 DGES on modified manifold (welded flange then grinded out for a smooth transition),also one of those billet bell mouths for them (It actually picked up a smidgen of midrange with it)
4-2-1 large primaries, 2 inch single glass pack muffler system
Pulsar electronic dizzy

Cos it was so lean (and my negligence) we could only get a smidgen over 6k, I've thrown two size bigger main jets in and she'll rev to around 7200-7400 which would hopefully get close to 100hp atw.

I don't know how to embed...