Re: Carb question Need answers tonight

Posted by Jack Vines On 2008/8/3 17:23:55

The formula says a 374" needs only 415 CFM @ 4800 RPMs. Packard did claim 20 more horsepower on the 374" Caribbean. Here are Packard's advertised horsepower figures:

374? w/1-4bbl - 290 HP @ 4500 - 400 lbs/ft torque @ 2900
374" w/2-4bbl - 310 hp @ 4800 - 405 lbs/ft torque @ 3000

My guess would be if in fact there were twenty more horsepower, it comes from the 2-4bbl intake being more efficient, not from the extra CFM. It would be interesting to put one on a dyno and see if the secondaries open and if so, how much. In theory the four primaries could supply sufficient air.

Very few stock Packard V8s will even turn 4800 RPMs. The valve springs were not up to controlling the long, heavy intake valves. The 352"s in many overdrive '56 Golden Hawks died trying. All three of the stick shifts I have pulled down showed evidence of dropped valves.

I just bought a 1956 Motor Trend with road test comparisons of the '56 Corvette, the '56 Thunderbird and the '56 GH. They made much of the Corvette 2-4bbl 265" having far too much carburetion for street driving. On that little 265", GM put two of the same Carter WCFBs used on the 352" Packard. The Golden Hawk was much quicker and faster than the Corvette and the Thunderbird.

thnx, jack vines