2 barrel analysis question
 

How does the Chevy 350 " 70 2 barrel at 1686 X 1375 compare to the "72 2 barrel at 1686 X 1260?

Is there a significant difference?

How about how much slower is the 2B to a 4B?

Thanks.

Re: 2 barrel analysis question
 

Joe, stick with the Q- Jet mileage won't be that much better with the 2 bbl. See you soon spring is coming I promise. Lee.

Re: 2 barrel analysis question
 

Don't know about the 350 , but my 283 was a turtle with a 2bbl...

Everyone told me it would ,but i had to see for myself..........
One day wasted with that project.............

Re: 2 barrel analysis question
 

Joe, there's a pretty big difference between the 2bbl that NHRA "accepts" on the 70 and the 71-72 2bbl. There's also major differences in the 70 and 72 engines if that's what you're looking at.
Give or take about a tenth one way or the other, you'll slow down a second.
Danny, the 2bbl that you had to use on the 283 is a small base 2g(same as my 307) and they're pretty horrible mainly because the top of the carb is so restricted. The 350s used a wide base 2g. There's one 283 stick Chevy II that did set a record with one though!

Re: 2 barrel analysis question
 

I have two experiences with the "big" two barrel.

In 2004 we compared Q-Jet vs 2 bbl on our 255-350 that was set up for IHRA pure stock at the time. It was a stick shift, with the mandated stock valve spring pressure and stock duration cam. The 2 bbl slowed it about .55 and it was further under the index, by about .15. We didn't need a rev limiter for either combo, it couldn't spin high enough to hurt itself.

Two years later, same car with a modern NHRA stocker engine and an automatic. This time the Q-Jet was further under the index by about .30 or more. As the difference between H/SA and M/SA is .70, this must mean it slowed 1.00 that day, although in my mind it was worse.

The 2 bbl was going through the traps at 5700, the 4 bbl at around 7000+. Changing the gears and converter probably would have helped, but we decided not to pursue it any farther.

Re: 2 barrel analysis question
 

I really think you guys are missing the point, Joe went from a big block to a small block then he read the post on cost per run and says to himself I have to go 2 bbl. I'll save on race gas. I'll be Angelo agrees with me.

Re: 2 barrel analysis question
 

Lee you are killing me.... I am laughing hard.

Thanks for the analysis.

So it would be a bad move I am guessing in '72 350/200.

Re: 2 barrel analysis question
 

Lee you think of everything...lol...

Re: 2 barrel analysis question
 

Joe.......Back away from the car seat down have a cigar the snow will go away.

Re: 2 barrel analysis question
 

Must be hanging out with Joe Zoom to much!:D At least Zoom has an enclosed trailer! LOL