Dan wrote:
> Advertised redlines aren't an appropriate measure since those are based
> on a combination of crankshaft, piston, and rod material, stroke/bore
> ratio, piston speed/acceleration, head/valvetrain design, actual
> head/cam flow capacity, desired mileage, and reliability factors. My
> guess is that the new Mustang GT redline is limited by its cast crank,
> pistons, and rods more than anything. In the end, all else equal and
> with the bottom end to support it, because there is less mass in the
> valvetrain to overcome, an OHC design will out rev an otherwise
> equivalent OHV design.
> .
> Dan
> 2003 Cobra convertible
> With some stuff and things
>
While some of the things you mentioned above might limit the redline of
a motor, the major one is the lift and duration of the camshaft. A
higher lift and/or duration will result in a higher redline. I went from
a basically stock cam in a 84 302, to a .554/.558 lift and .298/.306
duration and my redline went from approx. 6000 rpms to 7000 rpms.
Nothing else was changed, except to replace the pedestal rocker heads
with a stock set of 351w heads. As for a OHC out revving a OHV motor,
that's not necessarily true. The redline is the point at which no more
fuel/air can be delivered to the cylinders. One way to get more fuel and
air into the cylinders is to increase the lift and/or duration of the cam.

Gary