Another stupid head Quetion

[ZROSSA]

Guys, When you talk About heads and say for instance "195 airflow research heads", does the 195 stand for intake flow or intake volume?

 

If its intake volume then It really wouldnt have much relevance to the power making capabilities of those heads whold it? Thanks,

 

Douglas

[Guest Anonymous]

Yes, they're speaking intake runner capacity in cc's. It does have an effect on HP by flowing larger numbers of air at higher RPM.

 

It also has an effect on slowing the intake track at lower RPM's so that the low end torque of an engine generally suffers slightly because the the velocity is to low to fill the cylinder optimally.

 

To improve low end torque, you want smaller runners and valves, to improve high rpm power you want big runners and valves.

 

I'm sure one of the brainier flow conscience guys will jump in and give an opinion, but this is the way I understand intake runner size though.

 

Also note that the cam selection will have a say in all of this as well.

 

Regards,

 

Lone

[pparaska]

Thankfully, the newer heads that are really nice like the Twisted Wedge and AFR flow alot while having smaller volume runners.

 

Port volume really can't be totally tied to the highest port velocity, because it's the smallest cross section that will dictate (to some degree) the port velocity. Since the port is not ove constant cross section, and it turns, the velocity varies a great deal from place to place.

 

Vizard's book on porting the SBC heads is great and goes into this in alot of detail.

[ZROSSA]

Thanks guys.

You always come through with the goods. I have vizards head book and hopefully will start to read it tonight if the baby goes to sleep. I am looking for around 400 hp and it loks like everything is in order on the z i bought to do so. Just needs a bit of exhaust work and tuning and we will be burning up the road.

 

Douglas