Best carb for fuel economy?

[Jamie Miles]

My '72 Ford Maverick is (and has been for the past 7 years/171,000 miles) my daily driver. Current stats are internally bone stock 1980 200 from a Mercury Capri, SROD 4 speed O/D transmission, 2.79 gear. MSD-6 ignition/blaster II TFI coil, Duraspark II distributor, single out header that then Y's into dual exhaust, Delco 12-SI 90 amp alternator and an early 60's GM Rochester BC 167 cfm carb. Oh, and a Taurus electric fan on the radiator that's only on if the engine gets over 200 degrees.

I'm currently getting about 23 mpg in town (shifting at 1800 rpm, never exceeding 60 mph) and anywhere from 27-30 mpg hwy. depending on speed. Overall, the car runs and drives excellent and I'm very happy with this setup. It's not 'fast', and I don't need it to be. It runs along with traffic just fine.

Problem is, the carb, now being around 50 years old, has developed a problem where the throttle shaft is worn out and wobbly. Basically it's just worn out and I'd need to replace the bottom 3rd of the carb to fix it, which I haven't ruled out. But before I get into looking for a parts carb to fix mine, is there any other type of carb I should consider that may get even better gas mileage? I've had a Carter RBS and YF on the car before and wasn't really happy with them (never could get the YF to run right). Was thinking about trying something like a Holley 1904?

 

[bubba22349]

An Autolite 1100 or 1101 will have an edge on best fuel economy. If you can find a rebuilt Pony Autolite carb has some updates too. Than there are the Vaporizers that are brand new carbs built on the Autolite with an improved design.

 

[xctasy]

A history lesson since the reasons you have the Chev carb are simplicity.

It is the best 1-bbl carb in the business for performance with reasonable economy, and I can't offer any other advice except to find the new old stock parts from some HAMB er and rebuild it to suit..

The Chevy Rochester carb is the standard best upgrade carb for Series 1, 2 and 3 Land Rover four cylinders. The triple carb Weber ICT carb which can so easily make 180 hp in an Offy 200 cube tripower is an inferiour carb to this. Its a bolt on replacement for the Zenith 1-bbl carb used on the stalwart balistic Vauxhall Cresta/Viscount/Victor/Ventura 3.3 123 hp engines made from 1964 to 1973.


See http://landyonline.co.za/landyforum/vie ... f=8&t=1485

Specifically, the early Rochester BV 1 barrel (US after market) fitted to 215, 235 Chevy I-6, 1950’s were still 167 cfm too.

Rochester BV
Best overall performance (all of BP’s employees have used it, either now or in the past). This is a simple, robust
carburetor, good off road, easy to service, allows use of the stock or K&N air filters, and really improves top end
performance over the Zenith or Solex (top end power is almost the same as the Weber 2V). The Rochester BV
carburetor came on several sizes of GM six cylinder engines. The carburetor was equipped with a different size venturi
for each GM engine size. The venturi sizes are 30.9mm, 33mm and 38.5mm. The carburetor that you want came on a
235 CU inch 6 cylinder equipped 1954 Chevy. It has the 30.9mm venturi, a manual choke and a sleeve type top that
fits the neck of a Land Rover air cleaner. This carburetor is still available as a rebuild. Your 2.25L engine will not run
properly with carburetors that have the larger venturi sizes. This is the best option of all. It is easily adapted, and works
well. Parts are cheap and readily available despite their age. The Rochester will need to be rejetted. A 48 to 52 main jet
will work in most cases, depending on altitude and engine condition, and the model carburetor secured. Start with 50
to 52 for primarily low altitude driving or 48 to 49 for primarily high altitude driving. Too lean a mixture will shorten
the life of your valves.

If you track down the 235 modle parts or the later parts foryour version, you should get a fine result.

Best second step is a Weber 32/36

 

[rickwrench]

A Holley 1946 flows 195-200 cfm (depending on the info source), and is built for economy. Same family as a 1940, just flows a bit more, and is more refined.
I get low 30s with mine on the highway.

Rick(wrench)