[Shotimes] Interesting...porting the intake

[Mark Nunnally]

The more I read, and talk to folks a lot smarter than me, and tinker with
these things, it's more apparent in an n/a motor, the cams/intake runners
are a paired team.  Basically the stock SHO runners are designed (through
shape/size/length) to create the best resonance (ram air effect) where the
stock cams want to make the most torque.  When you shorten the length of the
runner, or enlarge the ID, you are changing the resonance rpm tune on that
runner.  You'd be moving it up higher in the rpm range.  I also think the
shape of the runner is important as well.

I think EH is probably the best (yeah it's $$$) method to "cleaning up" the
runners.  What I would be interested in is having somebody measure up some
EH runners and figure up the math to determine what rpm resonance that they
are "tuned" for.  Then build a cam profile to suit.  And of course
gasket/port match the runners to the heads.

One of these days I'll get around to port matching the intake/head runners
on the 3.2L (mine have a terrible mis-match, one of the worst I've ever
seen).  I borrowed an EH intake once and lost significant low end torque
(above 3k it would regain itself).  Never ran it at the track to see what
top end gains might have been there, but it seemed to pull hard.

Realize going much higher hp that what you can get out of a BOS 3.2L is
probably going to be maxing out the stock injectors.  I'm getting 90% duty
cycle on my stockers on my 3.2L now (at 216 FWHP).  If you are shooting for
300 hp some 30 or 36 lb'ers probably would be needed.

I think for open track work the stock cams/runners do pretty decent, as they
make a lot of torque over a broad range of rpm.  Personally I'd rather build
power through more cubes (3.4L anyone? <g>) and compression.  Ie, things
that will pick up the whole torque curve, and not just from 6000 rpm on.

I think if you EH'd a set of runners, had a cam profile built to match, on a
John H. type 3.4L stroker motor using about 10.75:1 (or 11:1) compression
(running on 94 pump gas) with a little more injector, I think you could make
an honest 300 hp with a GOOD torque curve.  Hmm, sounds like what I want to
build for the track 89 :)

mark