Stromberg Big 97 on a stock manifold?

[scicala]

"I'm thinking that the last AFB was on '63 340 HP Vette, and on the '65 409 hi-horse engines in sedans. DD"

I know this isn't Ford stuff. but the 327 Chevy also used the Carter AFB on the 300 HP version through 1965. The 327/250 HP used the Rochester 4GC.

Sal

[51 MERC-CT]

Originally Posted by Grassman

51 MERC-CT, what 4bbl carb do you use, I'm wanting to do he same on my 47 pu, thanks for your reply. Grassman.

Running an Edelbrock 1403 (500 cfm) with crossover linkage to orient the carb the way I want it.

[SoCalCoupe]

Great discussion, learning a lot here. Looks like matching the intake is not as simple as hoped for. Trying to learn the differences between all the 32-53 intakes. 49-53 intakes not worth the trouble on a stock 41 engine. There are five 32-48 single-carb intakes on eBay right now between $40 - $100. Pretty cheap to experiment on one of them.


Never heard of a "camel back" intake but if was trying to think up a name, that would be it for 4 of the 5.



Distributor is a stock 1941 diver's helmet so need unported vacuum for the advance brake like on my stock '41 manifold. Don't understand why none of the ebay manifolds have a vaccum port for the distrubutor and windshield wiper. Maybe they're all 42-48?


Seems like it wouldn't be too hard to just drill a vacuum port into a runner and install a bung, would it? Just wouldn't want to drill into a heat passage.


Just for the record, my performance goal is to comfortably keep up with 70 mph traffic on the interstate.

[V8COOPMAN]

Originally Posted by scicala

"I'm thinking that the last AFB was on '63 340 HP Vette, and on the '65 409 hi-horse engines in sedans. DD"

I know this isn't Ford stuff. but the 327 Chevy also used the Carter AFB on the 300 HP version through 1965. The 327/250 HP used the Rochester 4GC.

Sal

You know what, Sal? You Sir, ARE absolutely correct. I had completely forgotten about the 300 horse cars. In fact, never owned a Vette with any of the lower horse engines except for my very first....a '59 with 230 horse. Good catch! DD
.

[V8COOPMAN]

Originally Posted by 51 MERC-CT

Running an Edelbrock 1403 (500 cfm) with crossover linkage to orient the carb the way I want it.

MERC ....That is one NICE, well-thought-out adapter. Of course, I would have expected no less from you. Slick piece! DD

[SoCalCoupe]

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Obviously I’m trying to make this an easy job and avoid boring and sleeving an intake.


Maybe the first thing to do is simply chamfering an 1/8” around the bores to match the carb and intake surfaces and avoid the step. Maybe boring down an inch or two isn’t necessary. Stromberg really wants us to remove part of the web between the two ports but says “[o]pening up the web to around an inch deep would still do the job.”



Stromberg says, “BIG97s also feature a new oval shape, carved out just under the throttle plates, which brings the two separate barrels of air together before they hit the intake plenum. This ‘early plenum effect’ allows any cylinder to draw from … [both]… barrels combining the strong torque/easy drivability characteristics of a dual plane intake with the kind of power curve improvements more usually associated with a single plane.” Here’s a picture.


They go on to say that, “[t]he intake manifold modifications recommended here enhance that effect…”


Here’s Stromberg’s dimensioned drawing of the Big 97.





Their recommendation says, “Your first task is to open out the carb intake ports to avoid a step under the carburetor.” They also note that “Research shows that most of the flow is down the center of the port, with very little activity near the walls, so there is very little to be gained by perfect matching or polishing.”



Maybe I’m reading into it only what I want it to read but it would be nice avoid extra work.

[51 MERC-CT]

"Their recommendation says, “Your first task is to open out the carb intake ports to avoid a step under the carburetor.”

To me. this says it all for normal use.

[SoCalCoupe]

OK. I'll be the guy to try out a single Big97 on a stock 1941 flathead.



Spent countless hours looking at flathead intakes on the internet trying to understand the playing field, new to all of this. This one looks a lot like mine (stock 1941.) It has a "shelf" with a vacuum port on top of a dual plane manifold. Looks like it would be REALLY easy to port match (not bore) this to the BIG97 to remove the step and take out some of the webbing to mostly meet the Stromberg recommendation and not risk cutting through to the heat riser.




Very cheap to buy one of these manifolds on eBay.



What's bothering me though is how to clean the shavings out of the manifold before installing it so none of them end up in the engine. Really hung up on the cleaning step. Never done anything like this before and don't have tools like a pressure washer, media blaster or even compressed air.


Recommendations please.

[J Franklin]

Soap and water should be able to flush it clean. Use a hose & nozzle.

[34fivewindow]

Originally Posted by tubman

I thought the 365 HP 327's had AFB's or Holleys.

Only 327 with the AFB was the 300 and 340 hp engine.

[Ol' Ron]

I don't see the advantage in running a "Bell mouth" on the intake port to run a larger carburetor.
Gramps

[Bored&Stroked]

Originally Posted by 34fivewindow

Only 327 with the AFB was the 300 and 340 hp engine.

That is correct - had a 62 and a 65.