converting to a four-barrel carb

47topless

47topless

Well-known member
My engine is a stock V8 in a 1947 Ford. Would it be worth the effort to convert this to a four-barrel carb setup?
Thank you,
Phil
 
47topless said:
My engine is a stock V8 in a 1947 Ford. Would it be worth the effort to convert this to a four-barrel carb setup?
Thank you,
Phil
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Probably not. All of the manifolds out there (I have an Offenhauser, an Edmunds, a Fenton, and a Sharp) take the old "Square" pattern carb (early Rochester 4G, Carter WCFB, some Holley teapots and some very early Stromberg's). All are very hard to find these days, and usually expensive. An alternative is a 390 CFM Holley and an adapter, but the Holley's are almost $800 these days (there are Chinese knock-off's for under $300 if you're feeling lucky). Anything else will be too large for an otherwise stock engine. Even some models of the early carbs will be too large.

My solution is to use a small base Rochester 2G on a bored out late Mercury manifold. They bolt right on and when mounted backwards, everything but the manual choke falls right into place. They flow about twice as much as a stock 94, and are just overall good units. I have no experience using late manifolds on early (pre-49) engines, but I'm sure something could be made to work.
 
47topless said:
My engine is a stock V8 in a 1947 Ford. Would it be worth the effort to convert this to a four-barrel carb setup?
Thank you,
Phil
Click to expand...
Having tried a Holley 390 and an Edelbrock 500, the Edelbrock is currently installed and I found it to have better adjust-ability than the 390 to suit me.
The 4bbl. is used as a 2bbl., I would guess 99.99% of the time.
Unless you want something to play around with I would stick to a 2bbl. carb.
 
Absolutely I would; getting away from the old Holly and their inherent problems with today’s fuel.
I've had a small pattern 4GC on Edmonds manifold forever. I couldn't be happier with the tunability and the performance. There are a lot of rebuilders out there that are rebuilding/selling those carburetors for a comparable price to a new 390 holly.
I have a set of headers, 2 1/4-inch exhaust and angle milled heads. No other changes and the performance difference is amazing.
The downside of the equation is the distributor and tuning your crab to match a 4GC. I would think that would be challenging but something that is not insurmountable.
 
If the engine is stock you won't notice any difference by bolting on a 4 barrel.
Plus you may find that you need to add a 1 in. spacer between the base of the Holley and the intake in order to 'clear" the center radiator hoses on the heads.
Plus, think about your vacuum wipers and linkage hook up. Once you start changing stuff, other changes usually are required.

If you install a Holley 390, it goes on backwards to accomadate the linkage.
 

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biggest problem will be overcarbing just cant use enough air to make the carb work properly what most people don't under stand is its actual airspeed thru the cab that makes it work and a flathead is lucky to run at 85% volume at the best of times yes the 94s/97s have their issues so do others but then todays fuel is nothing like it was 50 years ago so its all about what you want there's no silver bullet. Personally im running a 48 Stromberg with high altitude jetting at close to see level [works for me ] but our fuel is different to yours
 
tubman; My solution is to use a small base Rochester 2G on a bored out late Mercury manifold. They bolt right on and when mounted backwards said:
I'm not sure that the Southern California flathead crowd is aware of the potential of the Merc manifold. I was campaigning at major swap meets, a pair of Mercs, one iron and the other a Canadian alloy. They might have been invisible as they never even got a glance. I left the original carbs on to punctuate their origin. I'm restoring a 59A for my '40. I say restore as the engine that came with the car and was an over cammed, over carbed, over, over, mess. The merc intake sounds tempting. It would sure finish off any attempt to look original. Thanks: Fred A
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If you are not overly tempted by the Canadian manifold, I will take if off your hands for a reasonable amount.
 
The early Rochester's were made so that the back two barrels did not open until you stood on it so most of the time you were running on just the fron two.
 
jimTN said:
The early Rochester's were made so that the back two barrels did not open until you stood on it so most of the time you were running on just the front two.
Click to expand...

Great minds think alike.
Over carbureting our (relatively) stock motors is a concern. Much has been made of the Rochester 2 barrel and Merc manifold. Very good setup IF the smaller CFM version AND a mechanical advance w/a vacuum can type distributor is used.

ANY 2 bbl carb is a compromise at best. If it’s small enough to give low rpm efficiency it runs out of air at higher rpms

Our 4GCs are nothing more than a very tunable progressive (2) 2 barrel setup.
The smaller CFM 4GC gives you the best of both worlds. AND simply increasing/decreasing the weight on the air valve the rpm when the CFM becomes available is very tunable
 
jimTN said:
The early Rochester's were made so that the back two barrels did not open until you stood on it so most of the time you were running on just the fron two.
Click to expand...

Don't all of the 4 BBL's (Carters, Holley's, etc.) work that way?
 
51 MERC-CT said:
Having tried a Holley 390 and an Edelbrock 500, the Edelbrock is currently installed and I found it to have better adjust-ability than the 390 to suit me.
The 4bbl. is used as a 2bbl., I would guess 99.99% of the time.
Unless you want something to play around with I would stick to a 2bbl. carb.
Click to expand...


I'd agree that a 2bbl is something to strongly consider with a stock engine. I bought a brand new, made in UK, Stromberg 97. Bolts right on. The performance difference compared to the 80 year old rebuilt Holley 94 was like putting a new engine in the car. No more carb problems. Very easy to tune. A stock engine can only flow so much air. The Stromberg 97 and Holley 94 flow nearly as much air as the engine can handle.



To be honest, I'm in the process of integrating 2 Stromberg 81's on a vintage Eddie Meyer intake but I don't really expect the performance difference to be noticeable on my stock engine. If I'm lucky it will probably be about the same as the single 97; it's mostly for the looks and bragging rights.
 
SoCalCoupe said:
I'd agree that a 2bbl is something to strongly consider with a stock engine. I bought a brand new, made in UK, Stromberg 97. Bolts right on. The performance difference compared to the 80 year old rebuilt Holley 94 was like putting a new engine in the car. No more carb problems. Very easy to tune. A stock engine can only flow so much air. The Stromberg 97 and Holley 94 flow nearly as much air as the engine can handle.



To be honest, I'm in the process of integrating 2 Stromberg 81's on a vintage Eddie Meyer intake but I don't really expect the performance difference to be noticeable on my stock engine. If I'm lucky it will probably be about the same as the single 97; it's mostly for the looks and bragging rights.
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"By George, I think he's got it!"
 
47topless said:
Wonder if they would allow that on a vanity plate? Now that would be cool!!!
DFWI47
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In Iowa they used to ask you for a reason for a specific combination they couldn't fathom. Tell them you worked at DFW airport at gate I47. It will fly.
 
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