Starved modified flathead

Keep in mind, this is a BIG flathead . . . there should really be no problem with 4 carbs that each only flow 160 or so cfm (total 640). I know it isn't apples to oranges, but what size carb would you run on a modified 327 Chevy? . . . probably a 600 or 650 Holley. Assuming the engine is in good mechanical condition (internally), he should be able to get this thing to run just fine with the setup he has - he just needs to learn how to initially setup the carbs and go from there.

Note: You can get jets from guys on this board, or even Summit. BUT - you should go through the steps that Pete gave you first - and it should idle just fine if you do. If it doesn't idle fine (with the jets and PV you have), then there are other issues (as at idle, you're not really using the main jets nor the PV anyway). For example, if you have a big ole' vacuum leak someplace - that can easily cause this issue.
 
Just in case I didn't see this mentioned , make sure the throttle shafts are .003 bushing to shaft clearance, I had this info a while back I can't pull it up from the search on here , the center carb is jetted different from the outer carbs an power valves are also different size, I 'll try and find this info in my files , this is something I would not delete, I have a very nice Edelbrock 4x2, I was trying to decide whether or not to keep it or sell it. I'll keep looking . I bought a bushing reamer to rebush my carbs and new longer throttle shafts.
 
I found the previous post , I can't get it to forward , it was on 11/26/17, under torque tool for Stromberg .97,.48 . It should help you out , it covers specs. for this set up . if you can pull it up on search.
 
I know, I don't know shiz from shine ola when it comes to this kinda stuff... but I would think engine vacuum would be a rare commodity at full open throttle or less, especially without chokes in some 97.

I only spend my weekends with one carb.
 
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Fordestes said:
Just in case I didn't see this mentioned , make sure the throttle shafts are .003 bushing to shaft clearance, I had this info a while back I can't pull it up from the search on here ,

" the center carb is jetted different from the outer carbs an power valves are also different size"

>We are talking FOUR (4) carbs here. There is no center carb.
ALL FOUR SHOULD BE THE SAME JETTING!!
And while we are here, on a three carb setup even with progressive (yuk) linkage, all three (3) are jetted the same for 20 miles to the gallon.


, I 'll try and find this info in my files , this is something I would not delete, I have a very nice Edelbrock 4x2, I was trying to decide whether or not to keep it or sell it. I'll keep looking . I bought a bushing reamer to rebush my carbs and new longer throttle shafts.
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dschwartz, I found the info. that was posted in 11/17 when I inquired about the 4x2 setup used on Walt Dupont's Engine, I didn't ask what cam or cubic inch this was for , so results may be different, .043 main jets in all 4, #67 power valves in the two MIDDLE carburetors and #69 power valves on the two end carburetors. Parallel reamed .003 throttle shaft clearance.
 
Unless you have the ability to do individual cylinder profiling, or carb wet flow testing, all the carbs should be set up the same. The one exception might be a log type manifold which would be a VERY poor performer below 3500+ RPM.
 
After you get it running the way you want, please keep us informed on the effectiveness of the A/C, cooling components and temperatures at idle, sitting in traffic and 'on the road"..

Really looks nice. Good luck.
 
That is one sweet looking flathead! I’d love to hear it run! I wish I had the cajones to attempt a four carb set up for the street, but I’m too chicken! Still I’m thinking of attempting a 300+ cubic inch flathead project someday. Where did you get the 4-1/2” crank?
 
Walt Dupont's 1940 Ford Coupe with modifies 276 ci flathead has 4 Stromburg 97's on it and he drives it every fay. I had a ride in it and it ran quite well, even at low speeds. This surprised me, but if you put enough effort into a project, you can usually solve most problems
 
RalphM said:
That is one sweet looking flathead! I’d love to hear it run! I wish I had the cajones to attempt a four carb set up for the street, but I’m too chicken! Still I’m thinking of attempting a 300+ cubic inch flathead project someday. Where did you get the 4-1/2” crank?
Click to expand...

You have one made - custom billet . . . with a large price tag attached to it! :)
 
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