650 brawler double pumper

[gntkllr]

[gntkllr]

Edit:

... so based on those details, I'd shoot for "safe" rich first with #72 PMJ's & 0.063" PVCR's, with 0.028" PMAB's, and #82 SMJ's with 0.025" SMAB's... especially if the OP is not going to address the emulsion-gone-wild situation, and not establish two per barrel properly sized (0.028") and located (~fuel level, inline with bottom of MB's accelerator pump passage, and ~7/16" below that)... and corrected IFR sizing and location can also have affect on WOT. Ultimately, with everything addressed, yes, it might be better WOT AFR dialed-in with #68 or #69 PMJ's and #78 or #79 SMJ's...

[Right hand drive]

[gntkllr]

With the "new and improved", it's the subjective "rich everywhere" that is the clear-as-mud problem. Seemingly never simply tuned out with the usual easier tuning changes...

Idle air:fuel ratio on a gauge is most times basically meaningless, and attempts to cover up other functional situations, like winging the throttle in the driveway, with large jumps in changes can have somebody chasing their tail for an eternity.

Idle, off-idle, and most "regular" driving will indicate (or will necessitate changes in) a carburetor's idle and off-idle circuits being dialed-in, or in the ballpark, or partly or completely out to lunch... which under sane classic (2x0.028" booster correction bleeds and conservative ~0.028" MAB's) conditions, puts the main circuit function where it belongs, far enough away from and out of the off-idle arena, but then still does take the most work to dial-in, if need be...

I don't speak for everybody, but I think most would prefer there being one variable for finding a flat, consistent WOT air:fuel ratio... that one variable being main jet size... I mean, why not? An engine is an engine is an engine, back in the 1950's and still today... a flat, "safe rich" consistent WOT air:fuel ratio isn't just for days gone by...

I think most would prefer one variable instead of three for main circuit function... firstly by industry, misinterpretation of booster correction bleeds for "emulsion", and manufacturing in over-"emulsion", and then having to install large MAB's to lean the upper rpm (some have not been able to enrich the upper rpm end enough with the biggest jets they had, lol), but/and still only ever achieving some kind of compromise "fuel curve"... complicates the very simple aspect of booster correction and MAB that brings in the circuit at a sane time and in a non-blubbering way, with flat predictable consistence. The "new and improved" almost always induce some sort of "fuel curve", with an early blubbery/slugging and rich booster initiation, and then veering lean (sometimes too lean) up the rpm band with a big MAB... really the polar opposite of what's safe and ideal for WOT. Over-emulsion and big air bleeds to try to counter it, really messes with and undoes booster correction, the original intent.

Holley's original booster correction bleeds size and orientation, and a conservative size MAB, makes for a flat consistent WOT air:fuel ratio, from bottom to top of rpm range, and allows the shear simplicity of the one variable being the main jets... and the simplicity and predictability is returned when the "old" conditions are returned, time and time again...

[gntkllr]

[Right hand drive]

[Right hand drive]

[77k5]

Wow , good read, a lot to process, still have not had time to mess with the brawler but now I am thinking of diving deeper into this. Thought I was pretty close but I am thinking maybe I will get two metering blocks and mod. them to try to do a comparison, hi and low ifr's and changing e-bleeds. I know just enough to really get things out of wack but I would like to learn. Doing this with an afr meter and a vacuum gauge is fun to see the changes though, I might be chasing my tail a bit. I do feel I have made my small block run a lot better but not perfect.

Thanks for all the information, again.

[FC-Pilot]

[tmoble]

https://www.ebay.com/itm/USED-HOLLEY-PR ... 6016.l4276

I don't know if this guy is known here or not That block is claimed to be original to an old style #4779 750 DP. I've bought stuff from him before, turned out OK. I'd MUCH rather have that than any overseas imitation. he's got other blocks up too.