Thanks for all the replies suggesting low cfm 4 barrel carbs instead of my Holley 390 cfm which boggs on takeoff.

I took the time to read "Holley Carburetors" by Dave Emanuel from S-A Design and learned the Power Valve (PV) plays a big role in the transition from idle to cruising speed. The PV adds fuel when the vacuum drops below a set level to enrich the mixture and keep up smooth acceleration from idle to cruising speed.

PVs come with one vacuum setting, but are available from 3.5 to 10.5 in Hg. settings. The trick is to find the right PV for your engine. Valve spring constants determine the PV settings.

My Holley carb came with a 6.5 in. Hg. PV. I change to a 7.5 PV- less bogging resulted. Went to an 8.5 PV and bogging was almost completely gone. I just ordered a 9.5 in. Hg PV and think that will fix the problem. Holley PVs are about $9 plus shipping. Hope this helps others with Holley bogging problems.


FranK Hainey