A buddy porting a set of his own heads wanted one of mine to go by... so I sent it to him. His part of the deal was to take it to a shop with a flowbench to get it flowed and ship it back...
Well, he came through, and here are the results...
I got these numbers from John, and was expecting a bit more from the intake... maybe it was the old valve job or how the heads were set up on the bench. :lol:
I know very little about how the flowbench was set up, only that the guy seemed pressed for time. I don't know if the intake opening was radiused with clay, or if the guy used a pipe on the exhaust. All I do know is that there were several years worth of abuse on the valve job... it was not fresh by any stretch of the imagination. The valves were 1.94" intake, 1.60 exhaust.
Intake -- Exhaust
.1 063 -- 050.9
.2 119 -- 101.3
.3 168 -- 132.8
.4 201 -- 157.1
.5 210 -- 175
.6 218 -- 176.6
My intake volume was 155cc. (stock is 126cc) Comparing to the best of the aftermarket competition, here are AFR's published numbers for their fully CNC ported non emission 165's...
intake -- exhaust
.1 ----- ----
.2 123 -- 118
.3 186 -- 153
.4 225 -- 178
.5 243 -- 185
.6 250 -- 191
As long as there is no significant shrouding, or the short turn isn't too messed up, larger vavles will flow more at lower lifts. They provide a much larger window... especially when they are only opened a small amount. However, opening the bowls up large enough for a 1.94" intake valve is QUITE risky. The metal get VERY thin when the WHOLE bowl is opened up to around that size. I'd say 351W valves (1.84" / 1.56") would be nice in a 289 head.
I might try widening the intake port floor as much as is practical before the short turn. (I didn't know this trick until after those heads were already finished and on the car)
The exhausts did surprisingly well. I guess my design there worked out pretty well.
If John wants to publish some pictures, that would be great... John, just the head up a tad first.
Do any of the rest of you have ported numbers for small block (especially 289) heads? If so, share them with us! I'm curious as to how these compare with the rest of the world.
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
[This message has been edited by n2oMike (edited 06-05-2002).]