Hey, what's up, everyone? Been a while since I posted a topic here, but I finally finished rebuilding my engine and, of course, now I am running into problems tuning the thing. It is a 400 big block Chrysler .030" over with Keith black 9:1 hypereutectic pistons, Summit hydraulic cam and lifter kit with 282 degrees intake and 292 degrees exhaust advertised duration with .465" intake and .488" exhaust lift and a 114 degree lobe separation angle, stock crank and rods, rebuilt 452 heads w/ 88cc chambers and a freshly rebuilt Holley 4160 style model 3310 dual feed 750 cfm carburetor. The carb has a Quick Fuel Technologies externally adjustable vaccuum diaphragm (really cool!!)and a new power valve. The cam is also advanced 4 crankshaft degrees. Initial timing is 15 degrees before TDC. It runs very well, but hesitates when the throttle is yanked open. The floats are spot on, the idle mix seems to be about right. I don't recall exactly what size jets were in the carb when I tore it apart, but I believe they were like #76 or similar. It has a Mopar performance electronic ignition distributor with the stock weights and springs (for now). My first thought was carburetion, but I adjusted the secondaries throughout their entire opening range and adjusted the accelerator pump cam and have seen no difference as of yet. Anyone have any ideas?
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