Mopar Action On-line – Tech Questions

Tech Question

brian yee, coquitlam, BC, Canada, 1974 dodge challenger 440

Hi Rick,
I’m not sure if you could help me on this one buthere it goes. I have recently stuck my Eddie AVS Thunder 4 barrel back onmy 440. I have an Eddie Performer dual plane intake with it.

Using an O2 sensor gauge, I’m trying to dial in the A/F mixtures at WOT and cruisehoping to achieve a leaner cruise mixture. I’ve got my WOT mixtures downpat at 12.5 – 13.7, but my cruise was too rich at 10.0 which I tried tocorrect with a rod change from 0.070 / 0.042 to a 0.073 / 0.042. The cruisemixture went slightly leaner into the 11’s, but nowhere close to where Iwould like to have a ‘lean cruise’ mix.

Since this is apparently the leanest rod to my knowledge from Edelbrock, what could I also do to lean her out? I was hoping for a cruise mix of around 15 or 16, but I’m way offthose figures. Thanks for all your help.

Pretty easy — reverse your procedure. Change jet for ideal cruise mix, thenuse a smaller power step (grind or file if necessary) to richen WOT up to12.5 – 13.2:1 or so.

However, since your cruise is, bizarrely, richer than WOT, it tells me thatthe secondaries maybe be lean (and the primaries rich). This is why I alwayssuggest locking out the secondaries and tuning only the primaries to start,then, once dialed in, go for the back barrels.



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