Slant Six Forum :: What to believe for carb tuning: O2 sensor; or plug color?

I than installed 54 jets, leaving 2.5 PV in place, This jetting gives mid rich to lean rich readings, dropping to rich side of lean under light acceleration with gage wagging back & forth between the to, and at WOT moves gage back to lean side of rich. Acceleration is flat spot free. There is not enough road with high enough speed limits near by to let this car run into high rpm with secondaryâ€™s & PV open for anything but a very short burst. 70+ mph in a 40 zone is unwelcomed by the local constabulary even in second gear if you get my drift.

I beginning to think this will be as close to an acceptable tune possible with a big cam.
Bill

Author:	wjajr [ Sat Oct 29, 2011 7:38 am ]
Post subject:
Got twin pipes all the way back. One would have to install a second sensor, and rig up some way to get tandem reading, a picture of all six at the same time, on one gage. Not sure how to do that at the moment.

Author:	Dart270 [ Sat Oct 29, 2011 3:10 pm ]
Post subject:
Quote: I than installed 54 jets, leaving 2.5 PV in place, This jetting gives mid rich to lean rich readings, dropping to rich side of lean under light acceleration with gage wagging back & forth between the to, and at WOT moves gage back to lean side of rich. Acceleration is flat spot free. There is not enough road with high enough speed limits near by to let this car run into high rpm with secondaryâ€™s & PV open for anything but a very short burst. 70+ mph in a 40 zone is unwelcomed by the local constabulary even in second gear if you get my drift. I beginning to think this will be as close to an acceptable tune possible with a big cam. Bill Now, yer talkin. I have jetted for lowest green (rich) light at WOT, and have gotten best ET's. I'd leave it there. W/o cam change, I'd say you are spot on. Lou

Author:	wjajr [ Sun Oct 30, 2011 12:52 pm ]
Post subject:
Lou: Quote: Now, yer talkin. I have jetted for lowest green (rich) light at WOT, and have gotten best ET's. I'd leave it there. Before the snow hit last night, I made a couple of pulls on my local red neck dyno at the turn-around at the end of my street. There is a fine selection of surfaces to choose; from nice clean asphalt to sand & gravel, and 600 feet of straight slightly up hill road to let her rip before nearing the neighbors. After this last jetting round, the car seemed to be more snappy off the line. Power braking yielded same lazy take off as usual, with a bit of wheel spin. However starting in second gear form a stop with light braking, than mashing the accelerator through the fire wall, felt like it took off much more aggressively. I donâ€™t know why this is, or it just just in my head. One would think launching from 2000 rpm while power braking would deliver a better response vs. 1100 rpm, which is just below where mechanical advance starts to kick in. Once the snow goesâ€¦ Yeah, when it goesâ€¦ Iâ€™m thinking we are in for a bad winter this year, it ainâ€™t starting out real wellâ€¦ Iâ€™ll drive the Dart a little more. My next experiment is to solder up the drill holes in the throttle plates, to richen up idle readings, and double check secondary throttle plateâ€™s air gap when closed. I had drilled the plates to get the idle mixture adjustment screws to work at about two turns out, and closed throttle plateâ€™s position out of the transition slots. Or, should I be talked out of this idea?

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