X, J, or 308?

[1wild&crazyguy]

The bigger the cubic inch displacement....the more port volume required in order for it to make peak hp at a higher rpm.

so while the 2 head examples would both work at under 4000rpm really well with say...a 360 cid ...the rpm at which the hp peak occurs would be lower with the smaller port/lower cc.

so where does the motor live, what rpm range is it used in?

bigger ports=higher rpm hp peak
smaller ports=lower rpm hp peak

its 100% true that combo's will dictate whats needed.

 

[1wild&crazyguy]

So, which is more important velocity or flow? Would the 318 head you ported in the stcky with the [email protected] 129cc ports actually perform better than a head with around [email protected] 179cc ports?

velocity is rate distance traveled...
flow is volume in a sense wether its fast or slow...
U need flow to make hp, you also need fast travel of that flow 'ideally'..
so a balance based on combo between the 2 is ideal.
then the volume based on cid displacement in order to run hp peaks a desired rpm
and even thats too general.lol

 

[kujo]

Thanks everyone for all of the information. I've got a much better understanding on this.