Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

"hogged-out" carb

Just read an article about “hopping-up” sports cars during the 1960s-70s . . . it mentions “hogged-out” carb. Anyone know what that means? Rocketman

Sounds like the author got his terms confused…Carburetors are delicate instruments and they don’t take kindly to being “hogged out”…If you want more air-flow you must install a larger carb…

He may be referring to removing the choke plate (and, throttle plate?) to lower the air flow restriction through the carb as much as possible. You don’t want to do that except for the race track, where maximum acceleration is all you are concerned with. For the street, is such a thing even streetable?

I wonder if the author meant using Hog Wash carburator cleaner?


I’ve never seen this done on automotive carburetors but have seen it done on older brass bodied motorcycle carburetors.
Hogging out was the process of milling out the bores a bit. Sometimes they were milled all the way through and allowed the use of larger throttle plates. In other cases they were milled out to create even more of a venturi effect.
This was often accompanied with drilling out the main jets.

This often took some of the low end torque away while in theory increasing airflow at high RPMs.
In regards to the motorcycles this was done primarily on old sidevalve engines which were low RPM engines and sluggish breathers. In racing they were running pretty much full throttle all of the time anyway.

The article appears in the January 2009 Road & Track . . . Peter Egan (page 29) talks about racing Bugeye Sprites in 1973 . . . and says " with a 13.5 to 1 compression engines with ridiculously high-lift cams, ported heads and hogged-out carbs . . . I’ve never heard the term. Thanks folks, sounds like you’re (OK4450) & (hellokit) pretty close to it . . maximum air or fuel flow. Rocketman

That might make more sense with a Brit car, the SU carbs were like motorcycle carbs, with a slide that I guess could be ground out to make for a larger max opening.

I think Peter got a little carried away with his prose…At full tilt, the SU slides would be wide open. These carbs would be destroyed by any “hogging out”…(I owned a '59 TR-3) You could gain a little throttle response by replacing the dampening oil with kerosene and removing a couple of turns from the slide return springs…The constant velocity design of these carbs allowed huge bores to be used so “hogging out” offered no advantage…