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Unoffical YB Fundraiser
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is that a 350 with a 30/30 cam and a 750 double humper carb and a set of fuelie heads ?
 

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Discussion Starter #10
Why did you cut it off at 6800? Looks like it was still climbing. What cam?
Just so everyone is on the same page, its a 5.3.
We stopped because he wanted to. Going back tomorrow
Heres the cam..
 

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It looks good but the way the BSFC ratchets up and down suggests it may have a little too much main or emulsion air bleed. The BSFC should progressively change from higher below the torque peak to lowest at the torque peak, then progressively back toward higher numbers above the torque peak, and the step changes should be similar values relative to each other. The numbers should not go up-down-up-down-up like they are. When they are plotted on a graph they should be a smooth bowl shape, not a sawtooth. Though it is likely the carb, if the carb is not over air bled, erratic BSFC can be from a mismatch of intake and exhaust tuning and valve timing, the three factors not being ideal for each other. With an unlimited budget so you could wear out a dyno you might find a different set of headers, or a different intake runner length, or intake type, or yada-yada, would fix it up and make more power in the bargain, but you have a nice flat torque curve now ….... so...it should be fun to drive.
 

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Discussion Starter #15
It looks good but the way the BSFC ratchets up and down suggests it may have a little too much main or emulsion air bleed. The BSFC should progressively change from higher below the torque peak to lowest at the torque peak, then progressively back toward higher numbers above the torque peak, and the step changes should be similar values relative to each other. The numbers should not go up-down-up-down-up like they are. When they are plotted on a graph they should be a smooth bowl shape, not a sawtooth. Though it is likely the carb, if the carb is not over air bled, erratic BSFC can be from a mismatch of intake and exhaust tuning and valve timing, the three factors not being ideal for each other. With an unlimited budget so you could wear out a dyno you might find a different set of headers, or a different intake runner length, or intake type, or yada-yada, would fix it up and make more power in the bargain, but you have a nice flat torque curve now ….... so...it should be fun to drive.
This was with a quick fuel 770 with all those fancy adjustments available but it is not my carb so we couldn't play with it.

To be fair we swapped off my 700 dp holley @ 418hp because it was going lean @ 6500. Gained 30hp and 30tq with the switch
 

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… but how's THIS dyno graph look? LOL



And you positively would not believe what it sounded like….
 
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