THADD

iTrader: (12)

We were on the dyno touching the tune up after a head swap and ran into a problem at 6800 rpm the motor would hesitate, blip, break up, or whatever you want to call it for about 300 rpms and then it seemed like it would recover right after. I am running a BS3 and it was reading from the passenger side header(o2) and the dyno was hooked into the drivers side header. The graphs from the bs3 and the dyno showed the same info at the same time so it wasn't one bank or the other. It was the motor as a whole. We change the crank position sensor and still had the same problem. Any info or ideas to check or try would be great.

jimmyblue

iTrader: (11)

Valvetrain resonance could act like this I suppose. The
point of float or resonance moves up with stiffer springs
and lighter components, but it's always there "somewhere".
Do you see anything kooky in the exhaust AFR readings?

Dunno anything about BS3 but might check that there
is nothing kooky in the airflow and spark maps that would
"stub a toe" as you slide across it.

THADD

iTrader: (12)

Ok so I tried load a tune that I had ran before that was problem free and had the same issue. I also tried running a tighter lash on the rockers, same issue. I have a beefier set of rockers I am going to try to rule out the ones I am running now being the problem.