Carb and Timing Baselines
 

Could use some suggestion on carb setup and timing for my new mill, 489 ci bbc with 10-1 compression, 088 rectangle ports, comp xm 270 roller cam 510. 510. lift 218-224 dur @ 050 with 1.8 roller rockers, thunderbolt ignition with MSD coil, performer rpm airgap with an 850 double pump, my question is where to start on jets and power valves, carb is off one of my drag motors and had powervalve plugs in it, have no idea where to start, next where to set timing, 32-34 is my thinking, will run 91 octane at all times, dont foresee running higher than 5200 rpm. Also is in a 24 sea ray that weighs 4200 lbs, intial prop pitch would help has a mirage 15x21 now but that was to small with the 330 that was in there, any tips would be appreciated.

6.5 PV in the front, blocked in rear.

pri jets 78's and secondaries 90's

timing at 32-34* is good.

These are about the same numbers I did on hopped up 454mag with an 800 holley and slightly bigger cam than you are using.

thank you my good man now i just need to find some cheap manifolds.

any one got any idea on how many pitch to go up to start with?

I went to a 25 3 blade on my 489"

Ditto or try a 24p B1

25 is what i was thinking, i could spin the 330 to 5500 with the 21 that is on there now, just trying to guage how high to go, appreciate everyones input.

keep an eye on detonation you're compression ratio is a little high for iron heads & 91 octane.

will run 93 from the sunoco around the corner