hi all
sounds like my feral built motor's getting a bit of mention

the engine being mentioned is the 2nd serious A series i've had built-1st an A14, 2nd an A12.
both achieved similar results and both were built by reputable builders of the A series motors.

details are as follows :
A14 - cleaned up bottom end, pretty stock-no balancing, flat top pistons. 70/30 cam, big porting in the head and 1600 exhaust valves, double valve springs, and around 10:1 compression. Regraphed points dizzy. 4-1 extractors and 2 1/4" exhaust, single sports muffler. Dyno'd with twin 1 1/2" su's and acheived around 90hp at the wheels. Changed carbs to twin 40mm dellortos, never dyno'd it again. This motor was in a 2door 1000 sedan and extremly fun to drive, although nothing really started to happen till around 3700rpm. Engine built by Gordon Dobie at Datsun Performance Centre.


A12 - cleaned up and balanced bottom end, incl-flywheel and clutch assembly, pistons and rods, lightened flywheel, 9.78:1 compression(flat top pistons), 60/33 cam, head fully rebuilt and cleaned up, ports matched to GX gasket, cambers marginally reshaped, new double valve springs and teflon guides, flowbenched. 4-1 extractors, 2" exhaust with single sports muffler. twin 40mm webers with 30mm chokes, electronic datrats bosch dizzy regraphed no vac advance. this motor was dyno'd on the same dyno (at least 10yrs apart ) and acheived the following : all readings in 5th gear
@100kph 40kw
@120kph 47kw
@6000rpm 58kw
in second and third they wound the engine out to around 8500rpm without the power curve dropping off dramatically. Cam comes in around 3000rpm before it's really noticable. Feral calculated an approx of 68 ft/lb of torque at 6000rpm.
this engine is much nicer to drive and more responsive right across the rev range, as well as reving out alot further before things start to drop off. Engine built by Feral Errol at Datrats.

both engines "comparatively" cost around the same to build, even though 10years?? apart. The A12 did however start out as a worked ex-autocross motor.

so ........... after all that 100rwhp is achievable out of an A12.

thanks for reading and apologies for the long post but but this topic seems to come up a bit with no real figures, out come, or advice for the person who originally asked it, so hope all this helps ..... to not confuse it