danltr450

I was looking at this flow chart and one thing doesnt make sence. The world heads jr's and sr's seem to be very low for flow numbers. I know that all flow benches are not the same etc etc etc. But I would think that a 200cc head would be closer to a 210cc head ( vic jr ) not the 158cc head (gt40) and as far as the jr's go how can a gt40 head with smaller valves and smaller intake port volume flow more???

http://www.thatmetalbox.com/automoti..._head_flow.pdf

my77stang

check the world sites to be sure. i can tell you that the victor jr outperforms the world sr. heads by a pretty good amount. dont get me wrong, the world heads are good, but they were among the first aftermarket heads available for the small block ford and their design has nowhere near the time/money/technology invested in its development as the newer heads do.

danltr450

I always like what you have to say. how about as far as the 40's out flowing them with smaller hardware and volume?

danltr450

I couldnt find flow numbers on the world website

danltr450

I am comparing world windsor jr's to the gt40s

my77stang

im not too sure there, but it wouldnt be too far of a stretch to think that without looking at charts. the windsor jr heads arent much bigger than a stock head (just like the GT40's)

i wonder how the windsor jr's compare to the early 351w heads, cause they are slightly lower flowing than the 40's

94IVGT

this site has the flow specs for nearly every head for almost all makes. great site
http://users.erols.com/srweiss/tablehdc.htm

danltr450

WOW. I am actually really shocked by the amount of information there is there. I cant beleive how close the 145cc gt40 head is to a 180cc world head. I also wonder if its that low how much improvement there is when you do some bowl clean up and port matching on the 180 heads.

67mustang302

Haha, ever since I posted that link everyone's been all over it. I do love that site, TONS of info. As far as what my77stang said about R&D and money into the newer heads, look at that site and compare something like AFR 165s or Dart 170's(165cc and 170cc intake ports respectively) to something like Boss 302 Cleveland style heads from back in the day. They both substantially outflow the BIG Cleveland style head at lifts under .600 with 165/170 ports compared to the Boss's 234cc intake port I think it was? That's what 30 years of R&D can do. Size isn't everything in a cylinder head, flowing the same as another head but with a smaller port = more velocity which = more power produced. Ideally you want something with a port size that matches your rpm range that produces the most flow with the smallest port.

As far as how much improvement on cleanups etc, cleaning up a bad head will make it better, cleaning up a good head will make it better. Start with crap and make it better, or start with gold and make it better, the choince becomes simple. Some heads just plain suck, and all the porting and cleaning in the world simply can't fix a bad design, they can make it run much better, but it'll never compare with a head that has a better shaped port with better positioned valves. GT40's are the best heads Ford ever producedfor a production small block car. Get good heads to start with and you'll be lightyears ahead

tinman

Ok then, consider this.........
257 X air flow in CFM X 8 = possible Horse Power.
This will only work for an un-blown 8 cylinder engine.
From some seat of the pants experience, I sort of think this is accurate.......