Technical Bashing my head against a stromberg shaped wall - need some insight from those who have gone before

well hello all.. its been a while since ive been on here, boy have things changed (looks really nice). But, to the point. I NEED HELP. Mentally, first off, and secondly tuning the triple speedway 9super7s on the 239 flatty in a 48 ford coupe.

Heres the story- I have ALL the Jets and power by-p*** valves that seem reasonable to get for this set up and have hit a wall, tuning wise; I am stumped and am turning to the only group i think can help. I have set up triple GENUINE strombergs many-a-time with no issue, im not new to the game, just incredibly frustrated and in need of some advice on this one.

Disclaimer-
Not my car - friend of mine's. he had someone build it and it seems that he managed to use every chinese knock off part available - ive been tasked with getting the thing running well and working (boy do I have stories)
There is no build book with this car -

Situation-
48 flatty 8 running 3 9super7's with progressive linkage at 6000' al***ude in SW New Mexico
fresh engine with edelbrock heads and intake. mated to a C4 (owner has bum leg - cant work clutch)
outboard carbs currently running 39 main jets and 71 power valves
center carb currently running 41 main and a 69 power valves
still running rich and choking on itself at about 1/3 throttle (just when the secondary carbs kick in) and down low.
runs gorgeous at idle and WOT when at higher rpms

Any and all help, comments, sanity checks, critisism, and funny comments welcome and appreciated!

-nummie

 

If it's "choking on itself" by going rich when the end carbs open I'd be looking at the power valves on the end carbs. Are they even necessary? I'd also try delaying the opening of the end carbs while also using faster-ratio links on them so that they open later but still reach WOT at the same time as the center carb.

If it goes lean and stumbles when the end carbs open I'd start by making them a little richer and delaying the opening somewhat. Kicking them in at 1/3 throttle seems pretty early to me, especially with an automatic transmission.

Just between you and me, if performance, driveability and ease of tuning is your goal with your setup you'd be much better off with a Holley 390 cfm vacuum-secondary 4bbl. There is so many variables with the 3-deuce/automatic combination that you might be tinkering with them forever...butcha' can't beat 'em for looks!

Good luck!

 

At this point...I would buy 2 blockoff plates and see if one of these things can be made to run right. If so, flog all 3 as singles til they work, and start over. Remember, you are caught up in a Chinese psychological warfare experiment, not just a mechanical process.

 

And re***ure your poor friend...even though they look odd and don't work, they were only a little more expensive than a core and a kit real 97...
Do all testing with no aircleaners...the Chinese make those, too. Ford called for 2 numbers down on real 97 jets at your al***ude, fwiw.

 

So true.

 

Thanks banjo, bruce, and missysdad.
I will continue forth with my sword held high and attempt to slay the chinese carb dragon.
Im going to try the block off plates, but I cannot run the outboards as anything but secondary carbs as they do not have an idle circuit... so one 2bbl it will be I guess

 

Well, flog the center one, then match its jetting on the end carbs, maybe add in winter pump shot and/or slightly raise float level to compensate for not having an off-idle circuit to run on until air picks up...
A Feng-Shui master can significantly speed up this process for you. Any Real Estate agent can suggest a good one.

 

A solution would be to remove the Speedway un super 97s and list them on fleabay.

Then drop Uncle Max a line and get a properly set up trio of real Strombergs.

 

What...! You're going to give up? C'mon, man, at least try to get 'em working before you block 'em off or pitch 'em out! All this anti-China stuff may play well a**** the troops, but it's nothing to base an automotive diagnosis on. At least do some solid homework before you throw in the towel, okay...?

Have you thought to contact Speedway Motors technical department for input? Might be a good first step.

 

I agree with Bruce. Three real Stromberg's are too much for a street flatty let alone trying to fart around with those Chinese ones.
Run the single and you'll be happy. ****ster27 can get you some block offs.

 

A small restrictive aircleaner will really make them run rich. The fuel bowl is vented to the atmosphere, not the inlet. A vac on the inlet is the same as pressurising the fuel bowl.

 

It might work with three. I'm saying tune the complete carb as a single, then use same jets in the end carbs and try to compensate for the lack of basic circuitry using accel pump and trying to get jets to tip in earlier. There are handicaps to overcome, but it might be made workable if carbs can be persuaded to function. NEVER do basic carb tuning with hot rod aftermarket or antique air cleaners in place, ever...gettem working, then see if your air cleaners restrict.
Big modern OEM filters are fine, but damn hard to use on a hotrod...

 

View attachment 2835552

Ohhh, pretty. Who's your daddy?

 

IMO Start troubleshooting simple. Remove air cleaners for testing. First, block off the power valves on the end carbs. Test drive. If better but still too fat in the midrange when the outers come in try dropping the jets a couple sizes. Test drive. Once you get it sorted, install your air cleaners. Now you can tell if they are holding it back as well.

 

pulled the carbs all the way down... something i havent done yet as the trottle plates can stay on the motor and its easier to change jets. the idle mix needles look like they were put in with an impact - all mushroomed over. if this is any indication of how the dude that put this thing together operated i think the emulsion tubes could be crushed also (can that happen in these like motorcycle carbs?) by over tightening the jets?

I blocked off the two outers (made my own block off plates at work out of 1/8" aluminum sheet on a CNC plaz cutter) and jetted the main carb appropriately. still ran like ****. thats what prompted the full tear down. Im pot commited to making these ******s run, the owner is somehow attatched to the trio. I think its about looks.

Hey BlueOne- I have a set of those that were promised to be "exactly the same"... trade you straight up! all kidding aside those three stroms are ***y. even the boxes are cool. when my ride comes together itll have those feeding the engine!!

Oh, and Bruce.. i contacted a real estate agent and a FengShui guy is coming next week - thanks for the hot tip!

Missysdad- im still slugging away - ill get the trio working if it kills me (which it most likely will)

 

If you replace the idle screws, get the ones from Uncle Max. They have big heads with knurls so you can do it by hand. Much easier than trying to snake a screwdriver in between carbs on a 3-2 setup. Uncle Max can set you up with all the Genuine Stromberg rebuild parts you'll need to fix your Chinese wonders.

 

Just a little update for all of you out in Hamb-land. Got sick of the chinese strombergs, friend wouldnt go for real Strombergs. got a Holley 390, jetted it for the al***ude and an offy intake and couldnt be happier. Ill try to figure out pictures later today.