Technical Setup questions using dual Holley 92 on a banger

I thought I may get a couple more responses it I started a new thread about this. I found a good matching set of Holley 92/81 carburetor with AA 7/8 bases to use on my build. I'm in the process of rebuilding them and need some input on what size jets and power valves I should start with. It is a 6:1, 080 over, with a Thomas repop intake, stock size valves and a Winfield 1R cam. I just looking for a rough starting point so I can order the parts. Any input is needed.

 

Really? Nothing

 

Not sure if this will help as I do not use Strombergs. Before I went to Winfields I was going to run two Stromberg 81's. In my notes I have that you should use a #71 power valve and .042 jets. Not sure where I got this info. Not sure if this will apply to the Holley.

 

I looked in them tonight and they have .043 jets in them now. As for the power valves they are 7.5hg stock and I have heard that 3.5hg to 4.5hg when running duals. But this isn't from anyone's real world experience.

 

I ran stock Stromberg 81s on Thomas intake, chosen because it was the rare manifold with matching bore diameter. Never got over the initial stumble, from the stock Strombergs. I had been using Holley 92/52(not 81) carbs singley on a Model A with great satisfaction. Tried 92s a pair with the4.5 PV and was able to tune out the stumble from the accelerator pump. The PV change does nothing to crusing but keeps enrichment at bay under light load. This was before they *ed up the fuel so reading plugs was useful and the feared lean mix was not appearant. This was all done without good carb knowledge. There could easily have been more elegant solutions unknown to me. Other factors possibly at play: B cam; stock exhaust; oversize valves; police head; real regular gas. Good Luck: Fred A

 

Thanks for the info Fred so did you use the stock .043 jets in the 92's or did you go down?

 

No direct Banger with Ford carbs experience, but some theory: You want jets pretty close to stock. Some slight decrease in size may be good because of very short/small area manifolding here...or mebbe not, as you may have some charge theft in the siamesed ports! Start with stock and see. Power valves, low number as you surmise as vac is going to drop off fast when carbs open.
Something to do here is to put in some time in fitting the throttle plates very closely, covered here a number of times. Free but time consuming fussing, not hard. Necessary to get decent idle because you have 4 throats open and they will need to be able to be cranked very close to closed with same size openings all around or you will never attain a low and smooth idle. Preliminary to synching work.

 

Went noplace. Someone gave me some power valves as a stab. I used some 5.5s later to tame other Chandler Groves misbehavior. Lucky I can remember those numbers. Good Luck: Fred A​

 

I would have stuck a pair of 1bbl zeniths on it. The air will move slowly thru those holleys and that is a bad thing in carb physics. Those carbs are designed to work on 8cyl engines where you have 4 pistons pulling air per cycle, the 4 cyl will have 2 pistons per cycle.
Just giving you something to consider.

 

Thanks I will start with 4.5 PV in them and try to see if the stock .043 jets can be dialed in I might also get a set of
.042 jets just incase they need to be slightly smaller. They seems to have a fair amount of adjustments built in to them to work accelerator pump adjustment holes are a plus as well.