Cranking pressures

[grandville455]

Hey Guys My brother has a 355 small block unkown cam specs,Only producing 3" of vac in park!! No vac advance also, just mechanical. Drops to 0-1 in gear! supposed to be 13.1 comp...-8 brodix heads,Vic junior intake, 850 annular custom carb, Running a msd dist with 18* degree bushing, running 36 total..is that too much timing?we did a cranking test and its around 265-270.. what octane should he be running? been running citgo 110.. ,but motor octane on that is only 106!!...

[hugger73hatch]

36 sounds like a good starting point, but may like more, may like less. You will be fine with a good 110.

[sunsation540]

did you degree the cam? sounds like it's small and over advanced way to much cranking comp by around 80lbs could be a circle track cam on 99* will run out of power under 6k sunoco maximal or c16

[grandville455]

Didn't degree cam.. its the way it was when he bought the car.. was built by guys that do make race engines for dirt tracks etc. he shifts it now at 6600, has run a best of 12.56 @113.. just has no bottom end doesn't come on strong till after 3-3500.. he is only running citgo 110 now