I am trying to get a leaner mid range for just cruising with a QuickFuel 650 BAN. Part of that solution is to run smaller primary jets. Problem is at WOT and 7 psi I am starting to go into the mid 12's on AFR. I am thinking of just popping in some 73 restrictors and using a power valve instead of jetting up the secondary mains more. Best carb I ever used was a Baker 830HP set up for oval track. Jets were square and had secondary power valve.
Already running 76's according to QuickFuel. They do not even list that size in their catalog. Will list complete specs this afternoon.
Just took the carb apart so get to answer my own question. The secondary metering block on the 650 BAN does NOT have a provision for a power valve. Here are my current specs: PRIMARY IFR 35 IAB 70 PV 3.5 PVRC 76 JETS 70 HSAB 31 SECONDARY IFR 35 IAB 70 JETS 76 HSAB 28 I think it is a bit strange that the HSAB on the secondary is a 28 and on the primary a 31. Is that because the primary open 1st? I think I should just drop some 80's in the secondary for the WOT. I think the IFR need to be smaller and then adjust with air bleeds.
The HSAB on the secondary is probably a little smaller to allow the fuel to start easier without the aid of a transfer slot, and support higher fuel flow without the extra fuel of a PVCR setup. Have you done my "carb tuning with wideband and vacuum" instructions on the idle circuit? Charting the AFR under several increments is crucial. Any throttle movement will affect the readings.
Just ordered some new ifr's and air bleeds. Re reading your tuning info. I did get out my good vacuum meter and worked on that yesterday. Curb idle is 950 rpm and almost 9 inches of vacuum. Timing is 22* initial 34* total with 1* pulled for each pound of boost. I added a lot of jet yesterday. 70 to 74 on the primary 76 to 84 on the secondary. Will get back to doing the idle tuning when parts get in. Not sure that I can take any jet out of it and still be safe. How much split can you have between primary and secondary?
Idle is getting pretty good. Latest setup: Initial 22* total 34* pulling 1* for each pound of boost. Primary side: IFR:33 IAB: 74 JET: 74 HSAB: 31 secondary: IFR: 33 IAB: 73 (do not have 74's and they don't seem to change anything anyway) Jet: 84 HSAB: 31 Idle rpm is now 950 and AFR's in the 14's still only turning the idle screws out 5/8th but gained inch of vacuum to solid 9 inches. In gear will drop to 750 and go a little lean then come back to high 13's low 14's Cruise is starting to flatten out stays in the mid 13's all the way up to 2500. WOT is in the 10's so I can start pulling some jet out of it. Going to go back to 70 in the front and leave 84 in the secondaries. With the big PVRC that should be close to square. Thanks for the tips.
Moved this discussion to blow through carb thread http://www.v8buick.com/showthread.php?208384-New-pictures-completed-engine-bay&highlight=sailbrd seems a more appropriate place.
