Cam is 264/276 @ 0.050, 0.657/.656 lift on a 108 LSA
6700 and pop bang pop poppity pop pop bang. I just don't get it. Shift at 65-6600 and it runs like a striped *** ape. (after 3 attempts to make some rpm's) Droped the plugs down to c-57's, jetted up real fat, reduced timing to 30 degrees and programed the shifts for 6550 for 10.51 @ 121.
That cam,,, 6500 rpm shifts,,, that's disgusting.

Rick I agree, having the same problem at the SAME rpm every time just has to be electrical. In chasing that thought I have put 3 complete ignition systems in the car (from distributor, to box, coil, harness and wires). When that did nothing I added an alternator thinking I was running out of voltage, nothing there, same rpm. Looking for RFI I completely rewired the car, added a 1 guage cable from the ground post to the block, then to the frame rail, built a common ground lug AFTER the block,,, nothing there. Cut every wire in the car and made a pass with nothing but waterpump and ignition (no tach, shift light, electronics, lights, cooling fans, transbrake,,, nothing but ignition, waterpump and starter), same crap, same rpm. Then in total frustration I built a little 355 and put it in the car with this ignition system and the little POS went to to 7400 like a song bird. A complete new fuel system with an-8 line throughout made no change in the 6-6.5psi I have when the thing hit's 6600 rpm. Different carbs and intakes, numerous set's of valve springs with PLENTY of psi, 2 sets of lifters, now a new cam, nothing is bending, nothing is flexing in the valve train. Cold the POS has a 2-4% leakdown, warm it holds more consistant at 2-2.5% across the board. Valve guides and seals are right, geometry is right,,, there is just NO REASON for the miserable POS not to rev. But here I sit looking at a 11.73 @ 100.5 time slip when I tried to spin it to 7k,,, and a 10.51 and 125 when I shift at 6500.
It will free rev in the shop up against a 7500 rev limit, but under a load (in 1st or 2nd gear) it hit's the 6600 wall. Trap rpm is ~6500 so high gear is clean but she is just starting to break up in the traps. I have built a high gear position sensor and am pulling 3.5 degrees of timing out of the motor at 6000 in 3rd gear only. With or without that it's the same scenario. The motor is a small chamber (55cc), flat top, zero deck, 12.49:1 POS running VP C-12. Dumping C-14 in it did nothing, running colder plugs did nothing, the only thing that seems to effect the wall is jetting up VERY fat and pulling timing out of the motor. Made a pass at 29 degrees total timing and jetted 6 sizes larger than it wants for this air and it picked up a hundred or so RPM,,, but ET falls off and MPH is down almost 7-8mph.
Same rpm every pass,, has to be electrical,,, been there done that. OK so fuel delivery,,, been there done that,, OK so it's internal,,, CAM. Well now I've been there done that.

For triggers jesper I started with a Mallory Comp9000 unilite and Hyfire IVc, when the problem started I blamed the ignition and ordered a new Mallory digital VI box. When that didn't help I pulled the Comp9000 and coil out of the truck, slapped a bronze gear on it and stuffed it in the Nova. Still no change. Then I blamed the Mallory digital VI and put it in the truck and ordered another VI. still no change. In frustration I ordered a new MSD digital 6 box, new coil, MSD billet distributor,,, exact same problem, exact same rpm. Not a thing changed in ANY of the ignition changes. Same rpm, same problem. I guess the other thing that is puzzeling is I put THIS ignition on a 355 last year in THIS chassis and it went to 7400 like a breeze.
Ignition/electrical is the only thing that makes any sense when it's the same problem at the same rpm. But with 3 total new ignition systems, a total rewire of the car, it makes it hard to keep pointing the finger there. BTW, thought about the headers. Had a few small cracks right at the flange and put new 1-3/4" supercomps on just 2 months ago.

The obvious question is what changed from when it went to 7400 to what it's doing now,, NOT A STINKING THING. Just one race she didn't want to rev to 7400 then 7200 then 6800. I started shifting lower and lower to keep out of the problem. Then started changing things looking for the problem (ignitionS, fuel system, carbs, intakes, fuel, alternator, wiring, valve springS, lifters, headers, cam, more intake gaskets than I care to remember, head gaskets, cold air pan, cam timing (+ and - 6 degrees) rockers,,, about all I need from the leftovers is a block, crank and rods and I can build another freeking motor.

Jesper in frustration one night I cut every wire in the car and ran a wire to a toggle switch for the ignition, and one for the water pump. No fans, no trans brake, no electronics, no lights, no shift light, no tach no shiftnoid, nothing but 1 wire to the water pump, one to a new dedenbear toggle switch for the ignition, and a hot wired fuel pump at the back. Oh and the two main feeds for the ignition box. Ran both the low side and high side of the (umm cough choke choke) MSD digital 6 I'm running now) to the top of their limits. Not a stinking thing did it do.
Saying it's not load related isn't exactly correct. Last friday night (in a fit of furstration) I sat there with the go pedal pegged in neutral and watched it rev to the 7400 high side limit clean as a whistle. In fact bouncing off the rev limiter is much much smoother than what happens at 6600 at the top of 1st and 2nd gear.

Yes. fuel PSI is 6-6.5 at 6600 and solid as a rock through the whole pass. As is oil pressure and the volt meter. Have ran gaps from 0.032 up to 0.045 and not had any difference at 6600. Oh,,, we are pretty sure the reversion (black soot) I was seeing in the intake was soft valve springs. When I checked them the Isky's had lost almost 40 pounds on the seat to 180-190psi. Suspect valve and lifter bounce was the cause there. The new pacaloys are up at 260-265. Only have 4 passes since these changes so i need to pull things apart and see how it looks now.

Cam is 264/276 @ 0.050, 0.657/.656 lift on a 108 LSA