Another Going carb ?'s
05-09-2009, 05:06 PM
#14
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Were did you get your dizzy at redony?
And i know a 750 is propbly to much but its free and whats the hurt in trying it. I mean its it loads up and floods and what not ill proply go to either the 600 or 670 holley
And i know a 750 is propbly to much but its free and whats the hurt in trying it. I mean its it loads up and floods and what not ill proply go to either the 600 or 670 holley
05-09-2009, 05:23 PM
#16
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the father in law was runnning it on hes old 427 but hes stepping up to either a 950 or a 1050 this time.
How do you adjust a carb? is their just just screws for adjustments or do you have to mess with the floats?
How do you adjust a carb? is their just just screws for adjustments or do you have to mess with the floats?
05-09-2009, 05:25 PM
#17
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Also i found a Victor jr. on line for $50. It has the temp sensor striped and a carb bolt stipped but i could get those helicoiled, do you think it would be to much for the motor or should i get it
05-09-2009, 08:56 PM
#18
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i went to advance auto. i like them more than the autozone or orelieys we have around here. those guys just give us crap everytime we walk in cause we have fords.... =/
05-09-2009, 09:43 PM
#19
D.R. THE PATHETIC DORK
Join Date: Jun 2007
Location: West Virginia
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if you use the right cam and head set up it, it won't be to much, however if you threw the parts on a stock 302 h.o long block then that parts combo may not favor/produce the desired results
05-09-2009, 10:33 PM
#20
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Carbs aren't nearly the restriction people think they are. Ultimately, intake vacuum at WOT and max rpm tells you what the restriction is.
Pro Systems for instance has found that the difference in power between around 1.5-2.0" and 1" can be rather significant, but they've also found that once you get under 1" it's not nearly as much of an issue as people think it is. Their testing showed that the difference in horsepower on a Pro Stock engine when restriction was cut by 40% from around 0.6" to around 0.35" was about 3-5hp. So on a street 302 the power difference between a 1" vacuum creating carb and a .5" would be maybe 1-2 horsepower at most. Not much, especially if it allows a certain carb design to operate better at lower rpm and make better streetable torque, or an overall better power band etc.
And for comparison, assuming you have a 100% VE 302 that makes 400hp at 6,500rpm, it's real world air consumption is only around 500cfm or a shade under assuming a good tune. With a 650cfm carb the intake depression at WOT and max hp rpm would only be 0.9", and with a 750 would only be around 0.7". So assuming everything works the same, the 750 would only be good for another 1hp at most.
That being said, if you have a free 750 and the booster and metering circuit is sensitive enough and it tunes right and works fine, then there's nothing wrong with using it. The trick is tuning it right, provided it's capable of responding to the engine. As long as you're not making more than around 1.0" intake vacuum at max hp rpm you're fine, once you're over 1" though the power losses can mount rapidly(compressible fluid dynamics is weird that way). On a street engine the power loss between 0.5" and 1" may only be less than half a %, but the power loss difference between 1" and 1.5" could be 2-3% or more.
Pro Systems for instance has found that the difference in power between around 1.5-2.0" and 1" can be rather significant, but they've also found that once you get under 1" it's not nearly as much of an issue as people think it is. Their testing showed that the difference in horsepower on a Pro Stock engine when restriction was cut by 40% from around 0.6" to around 0.35" was about 3-5hp. So on a street 302 the power difference between a 1" vacuum creating carb and a .5" would be maybe 1-2 horsepower at most. Not much, especially if it allows a certain carb design to operate better at lower rpm and make better streetable torque, or an overall better power band etc.
And for comparison, assuming you have a 100% VE 302 that makes 400hp at 6,500rpm, it's real world air consumption is only around 500cfm or a shade under assuming a good tune. With a 650cfm carb the intake depression at WOT and max hp rpm would only be 0.9", and with a 750 would only be around 0.7". So assuming everything works the same, the 750 would only be good for another 1hp at most.
That being said, if you have a free 750 and the booster and metering circuit is sensitive enough and it tunes right and works fine, then there's nothing wrong with using it. The trick is tuning it right, provided it's capable of responding to the engine. As long as you're not making more than around 1.0" intake vacuum at max hp rpm you're fine, once you're over 1" though the power losses can mount rapidly(compressible fluid dynamics is weird that way). On a street engine the power loss between 0.5" and 1" may only be less than half a %, but the power loss difference between 1" and 1.5" could be 2-3% or more.