Maxthe7man

You are taking the port the wrong direction for a motor past 7000 rpm, it is rather funny how you post excuses and added info after the fact just because you dont like what I am telling you.. The higher the rpm, in a race motor, the earlier the port needs to open, not just later to make more power. There is a point where later does nothing, maybe that will sink in this time...

88IntegraLS

I've always wondered if I took my aux too high, the real power gains over the series of re-portings I've done to it happened when I made the port open earlier and did some work to the exhauat port. Beveling the rotors was a big eye opener. I just had to get an angle on the aux closing edge and the only way to do that was to grind it up higher. I had no scissor angle with the side seals at first, otherwise I would have not taken it up so high.

Like I said, give me your six port plates so I can keep experimenting.

Kenku

All right, sorry... I've been interpreting some things poorly and getting irritated. Going to try to start over and explain myself a bit better, because I think that's been a hitch.

The question was whether it was possible to take it up high enough to be useless without running out of metal... IIRC, the 4-port irons can only end up closing around 70 degrees ABDC, though I'd have to check my piles of bits. S5 aux ports are closing at *80 degrees ABDC* stock, which makes me think that another 5-10 degrees wouldn't kill things... data I have says the late development MFR peripheral port motors were closing at 80ABDC, and that for motors designed to redline at only 9k for endurance racing purposes. Intake manifold tuning and gas inertia can overcome the fact that the chamber's reducing in size, to an extent... and mostly I was looking at extending past the stock port openings to get a better ramp for the side seals.

Yes, opening the ports earlier helps more, but there's a finite limit to what you can do, even with scalloping the rotors. Bridgeporting gets around that, obviously, but the racing class I'm looking at with this whole idea makes a bridgeport 12A run through a 48IDA with 34mm venturis to choke the power down, whereas a "street" port is completely unlimited. So the idea is to adapt 6-port end plates to a 12A.

Of course, it may end up needing a Guru-style multi-piece eccentric shaft to get a center bearing and make the thing not self destruct at high RPM, but I figure I'll worry about that later.

84stock

iTrader: (5)

My 6 ports are ported up rather high (see pics). Since this is on a supercharged project i feel it is quite effective. The other thing is that I have loads of torque out of the hole as well do to the immediate boost the s/c provides. It's a camden with an edelbrock 650 running the #8 pulley. I run up to 13lbs of boost with 10 straight out of the hole. Final fuel issues to be resolved this week with dyno results to follow.