jetting ???s

The RR is running pretty good after putting a wideband on it and seeing what its doing at idle, cruise and WOT, and making a few tweaks.

The idle was mid 14s and the cruise was high 12s to 13s. I richened the idle to around 12.8 and it idles best there and the cruise is now around 11.8:1.

Does it correlate correctly that going more rich on idle will have the same effect on cruise or should they not affect each other?

If I'm on the right track, I'll lean out the main jets one more size to start and then proceed with the outboards. It is in the 14:1 range when I go WOT, going down one jet in the primary carb will probably require +1 or +2 on the outboards.

I know a wideband may not be exact on the a/f, but the plugs are looking pretty good. The meter is a tool, so will tune to get it running right and good plug color. I'm not using the tool to jet for a specific a/f ratio.

Engine is the 505" 10.2:1 with Comp XS290S.

Let me know if I'm on the right track with the tune please, and thanks.

I ran my 518 C.i. pump gas 400 stroker 6 pak around 13.8 to 15.1 on the AFR at idle and real light throttle cruise up to 2500 RPM or so. It ran between 13.2 to 13.8 AFR at WOT. I like running a cold spark plug and as lean as I can get it to run without peppering the spark plugs, I shoot for 34 BTDC on the timing above 2000 RPM and 14 to 16 BTDC at idle, under 1100 RPM. What cylinder heads, iron or aluminum and fuel are you using. Mine had 10,78 to 1 comp. ratio with the last set of heads on it, I also ran non ethanol 91 octane OR pump fuel in it it ran a best of 9.96 at 134.+ MPH through the exhaust with the air cleaner on weighing 3400 LBs with me in it that was with a set of Indy SR M.W. ports and a Indy 400-3 intake and a Holley 1050 Dominator carb., the six pak set up with a set of CNC ported Eddy RPM and the six pak ran 10.01 several times at the same track on different days and weather Six paks can be made to rock

I don't have or use a wide band... I use a vacuum gauge, time slips and plug readings. I'd say make a hard pass, check a few plugs and adjust from there. If you feel it's running hard leave it. I'm a tad rich and to lazy to drop to 68's. When I pull the carbs to put the NOS plates on I might drop it down a tad. I'm not running outboard plates yet so I have no idea how to adjust those.

I dont know if this helps you out but maybe for some preference !?

In my 505 Six Pack stroker whit around 11,5:1 and roller hyd cam i use 66 main jets in center carb and 86 main jets in outboard carbs. The spark plugs that my engine like best is Champion RC12YC and it works for me and i have tryed several heat ranges !