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Author Topic:   rochester ideas!
rickb33
Member
posted December 26, 2002 10:42 PM
Are you sure of that number? It doesn't cross to anything I can find. Is it a Marine Carb maybe? http://www.carbs.net/quadnumber.htm


KPLugnut
Member
posted December 27, 2002 08:30 PM
The 838 carb is an EXTREMELY rare find. It has the same 1 3/8" dia venturi as many many other castings we've found over the years. The one mentioned above happens to be from a 1972 model year. The 4-5 years spanning that era (69-74) are probably the easiest to find 138's, 118's, and other such big bore bodies.
All of them will have the same diameter throttle bores (1.687") as do almost all the commonly found 2G designs.

In addition to the few mod's mentioned above, there are dozens of other things we do to improve the fuel curve, idle circuit responsiveness, and top end power of these carbs. Many of which cannot easily be done without special tooling.
Simply removing the parting line in the venturi and the vent "scoop" will gain maybe 25cfm alone on the flow bench. Hardly enough to show on a dyno let alone a stopwatch on the track.
The trick to overall performance gains is in the entire fuel management package throughout the rpm range, i.e, how the carb meters fuel at all times, and how well it is mixing it with the incoming air.

Hope that helps.

KPLugnut

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