Well I certainly don’t discount the BS meter is a useful tool, ha, as a reality check is always good.
I don’t know about Jay, but I ran mine at WOT intentionally long enough to know what it felt like. As I got into the high range, I kept pushing the throttle forward until I got to a point of diminishing returns, backed off a little and it seemed to give a bit more smoothness. I didn’t get any lean popping as in fuel starvation.
I am no expert at all with the AFB, as I'm especially accustomed to the SU and Zenith Strombergs with the vacuum operated dashpot, where you need to run at a steady speed under load, read plug, and then you know what the needle is doing to you at that rpm. If you are lean at that rpm, you select a needle that is tapered a little more at that segment of the lift, and that provides more fuel at that specific rpm. I ran several solid lifter motors in my former life with those type of multiple carbs, high compression, ported, hot cams, with a totally custom stage of tune. After reading plugs at low, mid, high, and ultra high rpm, you would eventually get a motor that was totally tractable over the entire range.
The AFB style carb just doesn't work that way at all. What I think I found with my 327F+ was a flat spot up around 4000 or just under, and it didn’t appear the 4 bbl was acting like a 4-bbl. Based on my limited experience with a less tunable carb like the AFB, it feels like a lean condition. I can’t select an adjustable needle like a SU or Zenith Stromberg, but I can cause the butterfly to open a bit sooner. What do you think, Bill? Do you think the motor is producing what it can as a 2-bbl, or should I be getting something from that secondary set of carb ports? Granted, opening the secondaries may just choke out the motor at high rpm by dumping a lot of fuel in, without the compression and cam to handle it.
The guy I talked to today was at the following number, Tech Line Only: 800-416-8628
If you talk to him, the motor I'm running is 8.5:1 and probably a 250 hp version of the 327. Jay is running the 8.0:1 marine version at 210 hp.
Comments are welcome!
Regards,
Paul