One of the Renault F1 shops in France acheived 270ish on the intake side on 65 casting 289 head, for a naustalgia closed course car in europe.
That set-up was on a 289 with webers, that we got 460 hp with, using a flat tappet solid cam and stepped headers. pk hp at 6900
same heads on a 331, went close 500 hp, peak hp ~6700 rpm
the 460 hp value is right in line with what the NHRA superstock guys are getting out of the 64/65 289 combo, and the mid 85 4v-302 build-ups. they are getting closer 500 hp, using much better valve train and roller lobes.
Around 235 before you start loosing air flow at .1, .2, .3 lift figures. After that the RPM you need to turn and the expence to do the port work and parts needed to servive at high RPM becomes too much.
More meaningful would be how many cc did he open up the ports?
stock E7 about 127, stock GT40P being about 145. Too big a port
will kill low end response. I'm certain the old tunnel port could
be made to flow more..but why?
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