Port size for a 3.2ss

[dweymer]

I am planning my engine build and wanted some advice on what size ports I should run.

It will be(so far)
3.0 case and crank
3.2 cylinders bored to 98
JE 9.5:1 pistons
DC40-mod's' cams
Webers
headers
single plug

Heads are currently later 34 intake with 35 ex. ports. I want to open them up some, but don't know har far to go.

[jpnovak]

Open them up to the early SC size - 39mm This will put your port velocity at the peak range of around 105 m/sec at 7100 rpm (peak HP for Mod_s). Anything much faster than 100 m/sec will not flow enough and you want to maximize port velocity. Also, larger port sizes will be restricted by the carbs on top. I recall you are using weber 40s. Don't forget to match the carb manifolds to the heads.

thanks to John Leutjen for this velocity calculations.