Technical Lets talk flathead intakes

I am running two holleys on a Edmunds intake now and have them jetted pretty well where they are. Good problem to have . My son came in from Calif. and surprised me with a Navarro 1221 tri-power intake and three rebuilt stromberg 97's and a rebuilt Holley 94. Love the look of the three carbs and I am sure running on the center carb around town is beneficial. But am I concerned I may be "over-carbing" the engine. Engine is a new build Edelbrock heads mild cam, runs great as is.
Probably will be installing the tripower but wondering about base line jetting for both the different carb set ups. Know this has been debated relentlessly over the but years however pretty comfortable with the Holleys. What is the advantage of going Stromberg? Can I lean out the secondary carbs to avoid flooding the system? Thoughts?
Never stop learning even at my advanced age.

 

How big is your engine and what, if any, other modifications have been made?

 

Cool factor on stroms would be pretty high. I also like the tri look on flattie, but also have read it's pointless, just hook up two, etc.

I'm more of a "if it ain't broke don't fix it" guy sometimes, and the duals probably look pretty cool, no?

 

I'm also running two Holley 94's on my flathead and went from solid linkage to progressive linkage where the secondary carb starts to open at about 60% throttle and is fully open at the same time as the primary carb. Seems to run better this way, tri-power would be the same but a lot more fuel and air when the two outside carbs kick in. All three carbs wide open would be pushing 500-600 cfm which is a lot for a flathead.

 

3 carbs are really to much. Even 2 can be a problem. Remember one 97 pushed a 100 hp flat motor. Depends on how your engine has been built. Some run 2 81s which is near perfect if you can find them. Linkage can help. 2 94s can be a problem because the power valves run off of vacuum and dump to much fuel. Best to at least block off one power valve with plug. 97s don’t have that problem because they are mechanically operated with pump. Any way factors to consider are driving. Most of us drive low and midrange. So one 97 or 94 is good or two with progressive linkage. A built flathead can run two with no problem with out progressive linkage. Experiment with any of this and see how it runs. Good luck.

 

If it’s running well on two carbs I wouldn’t change it. There’s absolutely no advantage on an extra carb for that engine.
What distributor are you running??

 

Running petronix electronic

 

Well, can’t insult your son. Build another car with a FH now!

 

You've never posted what your engine specifications are? Cubic inches, cam, etc.. That would help a lot.

You could surely run the 3-carb setup with a progressive linkage, which kind of gives you the best of both worlds - a single carb when you're cruising and the 2 extras when you want a bit more fun and higher revs. There are different power-valves designed for different vacuum signals. Some guys block off the outer two - some run all three . . . kind of takes some experimentation with the engine on the road to really know.

Regardless of how many power-valves, you need to use a vacuum gauge to understand your vacuum signal under load, so you can purchase the right PVs. Also, I recommend going to a company Daytona Parts for the PVs . . . as the newer Holley ones do not seat correctly in the older 94's.

If you have three rebuilt Strombergs - and they were done correctly (who knows?), then this setup works just fine as well. They've a little easier to tune than your 94's (due to no vacuum operated PV circuits). It usually comes down to "style" more than performance.

Here is a link to Daytona:

Daytona Parts Home

 

Not that thrilled with the new intake set up I have and appreciate the input. Having looked over everything I have decided to "can" the tri-power idea for the foreseeable future. Still may swap out the Holleys for the Strombergs though. Thank you

 

Will look great on a shelf too!