Offenhauser 3-1V versus Oz 250 2V

PROS:

1) WOW Factor. Any multi Carb set up is going to draw more looks at shows then anything else, especially on a 6 cylinder.

2) Extremely good breathing for the engine, especially at higher RPMS when the outer carbs are fully open.

3) Does not sacrifice much fuel economy so long as you don't punch the gas too much. :)

4) These intake manifolds are still fairly common on the market.

5) Lots of upper end power.

PROS:

1) Simple set up using only 1 carb.

2) Nice long runners for good low end torque

3) The head really increases the breathing ability of the engine

4) Easy to tune.

5) Makes it easier for future boost modifications.

CONS:

1) Complicated set up. Anytime you run multi carbs, you are making the set up more complicated. While this is progressive and is not as picky as other multi carb set ups, it does require a little more tuning

2) Can be prone to vacuum leaks.

CONS:

1) For unknowledgable people, they may mistake this head/intake for a stock set up.

2) The head and intakes are getting harder to come by, and more expensive.

So which is better performance wise?

I guess this is the question I'm asked the most about since I am one of the few that has run both set ups. While I scraped the Offenhauser set up for the Aussie set up, that is in now way a reflection of which is better. I went to the Aussie set up because I wanted a more simplified set up and a good base platform for future, forced air modifications.

As far as power, the Aussie head has more low end grunt since it can rely on the extra flow at low loads. The Aussie head also usually has less pedal effort since it has less springs to close the carbs.

As far as upper end power, I think the Offenhauser may have a slight advantage due to the short intake runners and the ability to flow over 500 CFM right at the intake valves. At upper RPMs, the offenhauser set up just screamed and sounded like a huge engine under the hood. The Aussie flowed great, and some of the difference may be that my 4V carb only flows 390CFM where my Offy set up flowed about 500 CFM. It is very probably that the Aussie would do as well with a larger carb. Some people have had great success running as high as 600 CFM on the Aussie head. With my current set ups, WOT at high RPMS, the title goes to the Offy set up.

So in the end, it is really a dead heat which is better. The aussie offers a little more simplified approach to power, but is becoming harder and more expensive then the Offenhauser to come by. Overall powerwise, they are about the same.