Just wondering if anyone has the oe cams specs. By that I mean degrees BBDC/BTDC of valves opening/closing and duration. Thinking with a better cam setup more boost would be achievable without shaving pistons and what not
but not sure on the stock setup
The cam timing holds this engine back. The general consensus with most people that have commented so far about the 6.9/7.3 is that the heads can flow the air, the intake certainly has the volume, and it has the size. The injection pump can produce the fuel volume stock, and the injectors can be made to flow. But in the end, especially based on the numbers seen on the chassis dyno, there is a serious mismatch somewhere. And, like one poster said on another thread, most folks don't want to push these engines.
Even though more boost would be desireable, because of the cam timing the engine has a hard time processing it all. It's like the engine, as configured with the stock cam timing, is fighting itself, and the added boost makes a bad situation worse. So goodbye weakest link in the cylinder.
Freight Train asked me if I would sell a cam that would work with the stock bottom end, and I turned him on to Jones Cam Designs (704-489-2449) so he and anyone else who wanted something special can get it made. I talked to Mike yesterday and he can get a lot done with the stock cam core, as a regrind. Russ (typ4) has a torque grind that works really well.
For a street motor possibility, working with existing set ups, I would propose the following:
Slightly larger turbo that can flow enough air for 350-375hp that can bolt up to the pipes of the Hypermax, ATS, Banks system.
Custom street performance cam that will run strong from idle to 3800 rpms or so. The cam will redline at 4300 rpms, but with the hp peak is at 3800-3900 rpms, there would be no need to rev it past the stock governed rpm of the pump. With the extra rpm available, and the extra airflow because of the engine speed, extra boost wouldn't necessarily be needed. And it will fall within the structural limits (rpm wise) of the stock internals.
Injectors that can match the hp goal.
Mike's cams don't lay down hard after the power peak, as ground, unless the customer wants that to happen, and they offer the broadest powerband within the rpm range the customer chooses. No weird harmonics either.