Quote:
Originally Posted by minytrker
I dont know anything about flow numbers or porting but those numbers seem high to me. I got this from AI's webpage
"Typical gains for our CNC work are in the 20-30rwhp SAE range over the as cast 241"
Those numbers seem more inline to me, but I know zero about porting.
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cylinder head flow determines what HP an engine is capable of making. when I say HP I dont mean rwhp numbers either.
the simple formula is 1.5 hp per cfm for a hot street engine
2.0 hp for your run of the mill cookie cutter race engine
2.2 for balls out, high comp, low tension ring, gas ported piston type deal
so a 40 cfm increase x 1.5 is a 60 hp gain. If you dont make that 60 hp gain then there is a reason like the cross section area of the intake is the restriction
that brings me to some more heads that I flowed today
I'll start with Texas Speed PRC 243 cnc heads with 2.0 valve
.1 72
.2 137
.3 199
.4 241
.5 284
.6 307
these heads have the rocker bolt hump and swirl hump removed, also the cross section of the port was wider than stock. if you bolted a stock intake and gasket to this head, it surely would limit its potential because the intake and stock gasket is smaller than the port
also brought over today was an AFR 225 cathedral port head with 2.08 valve
.1 75
.2 141
.3 203
.4 250
.5 290
.6 319
Also flowed today and I'm completely embarrassed about this because I ported these a few years ago, were 5.3 heads with 1.88 intake valve
.1 70
.2 134
.3 190
.4 216
.5 245
.6 253