Intake Manifold Options 340

-
rumblefish360 said:
That carb cfm difference was probably 10hp at best. A bigger carb doesn't automatically mean you'll go faster, as you have noted.

Good post.

I am about to run the next size up VooDoo cam in the wife's 10-1, 360 w/Edelbrock heads and TTI headers. It will have the Weiand Stealth on top with a 650 Thunder AVS.
Click to expand...

I had made the decision to swap the smaller carb after reading a few carb comparison articles. On a small Chevy, there was a comparo done between a slew of Holleys from 390 up to 950, all mechanical secondaries. The difference in peak and average power from the 650 to 750 was so slight, probably 4-7 hp IIRC, but the response was so much better with the little guy. I have not put my car on the dyno to personally prove it, but my *** dyno tells me that the smaller carb is a better choice. Pulls like a bull to 6500 and that's all I need.
 
Jay_340 said:
I had made the decision to swap the smaller carb after reading a few carb comparison articles. On a small Chevy, there was a comparo done between a slew of Holleys from 390 up to 950, all mechanical secondaries. The difference in peak and average power from the 650 to 750 was so slight, probably 4-7 hp IIRC, but the response was so much better with the little guy. I have not put my car on the dyno to personally prove it, but my *** dyno tells me that the smaller carb is a better choice. Pulls like a bull to 6500 and that's all I need.
Click to expand...
Did you check your a/f ratios? And did you do any jetting changes on the 650? I'm curious. Back when I was young lad in high school o borrowed a 625 Carter avs while I rebuilt my holley 750. I lost so much power I couldn't spin the tires in 2nd gear. After the holley was back on, I had spinning in 2nd and 3rd gear.
 
340swinger4spd said:
Did you check your a/f ratios? And did you do any jetting changes on the 650? I'm curious. Back when I was young lad in high school o borrowed a 625 Carter avs while I rebuilt my holley 750. I lost so much power I couldn't spin the tires in 2nd gear. After the holley was back on, I had spinning in 2nd and 3rd gear.
Click to expand...

I did not check the A/F, nor did I change the jets, but interestingly enough, when I decided to pull the 650DP and give it a rebuild, I tossed on a new-ish 600 Eddy temporarily and the same thing happened. Just felt like the motor forgot how to motor. I had never been more excited when I got the Holley back on. I mean, the 750 was a damn good carburetor. I'm not trying to bash it at all. The 650 just felt more responsive with the same amount of all-around power.
 
Buy a used edlebrock RPM for $160

Sell your performer for $100

$60 net for the upgrade!
 
My favorite carb swap was from an modern 600 AFB to an OE small 630 AVS that was borrowed from old boss. The car just WOKE UP after that swap. Holy moly!
It was many many years ago. Living and learning by doing.
 
It's great when you can find a used part in a timely matter doing a build. But, to wait until you find it, for me there is time/ cost of a new one. After selling my old one I paid $175 from summit for the airgap.
 
You must log in or register to reply here.
-

Back
Top