supermx96

I have a question about my carb jeting on my engine setup,
engine is 468ci gen 6, 8:1 comp ratio, Edelbrock alum ported head, hyd roller camshaft, b&m 250 blower @ 5.5 - 6 boost, twin QFT 850 marine blower carb boost ref, run it at 5500-5600 rpm. With that to achive an AFR at 11 WOT and a AFR at 12 at 3000 rpm i need to jet the primary to #77 with 4.5 power valve and the secondary have jet #106 so does it have any problem to run them with a big diference between the pri and sec jet size?

At 3500 rpm the power valve is open due to 0 vacuum and that rpm is my cruising speed and the AFR drop at 11, i know that is a rich mixture for cruising but i dont know what i can do to make the cruise speed leaner without afect the WOT AFR too much because i have already some big jet in the secondary.

supermx96

Any thought on that??

FIXX

iTrader: (2)

? do you have a powervalve in the secondary circuit?

supermx96

No power valve in the secondary, comme new with # 78 and 4.5 power valve pri and 88 sec no power valve.

vintage chromoly

iTrader: (3)

You should have some vacuum at 3500 rpm's.

Your power valve should open when you first open the throttle plates and you have no airflow yet. (No vacuum). Once cruising at 3500 you should have 10 inches or so, depending on the cam.

supermx96

No vacuum and no boost at 3500 rpm probably because of the blower spining and the load this is in a Scarab 29 single engine.