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Discussion Starter #1
The only change i made on my bbc was to back off the fuel pressure from 8.5 to a recommended 6.0 psi . now above 4500 rpm it surges and pops a couple of times.its a dart headed 468 with a holley hp 1000 carb.i know i can turn psi back up but it seems like i may be covering up another problem.most folks say no more then 6-7 psi on the holley carb.any thoughts on my issue and is 8.5 psi to high if it seems the motor likes it? bg 280 pump-bg5000 filter #10 line cell to pump-8line to regulator. could there be a restriction in the fuel supply?
 

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Discussion Starter #3
ill have to check out the regulator.maybe look at filter too.im going to try another psi gauge.car was running good, why do i have to screw with things..lol
 

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i did not check the floats after lowering fuel pressure.first place ill look this weekend.i did check the filter and regulator,they were free flowing. plugs look a little lean [ grayish ] so ill throw in some plugs and see how it runs.thanks for the input guys..
 

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years ago I read an article in Super Stock and Drag Illustrated about a device that was attached to the fuel bowl of a carb; it told how much fuel was in the bowl while they were running an engine on a dyno.as I recall, it could be hooked up to a data logger also. I've never heard of or seen one again.but anyway,to the point, the article stated something to the effect that high fuel pressure can cause aereation of the fuel in the bowl,and that raising the pressure actually restricts flow from the reg. , low pressure increases flow.seems it made mention of some P.S. teams experimenting with large needles and seats and very low pressure .I tried some .150 needle and seats and 4psi on my 10 sec. street/stripper, and it ran exactly the same e.t., so I put the .110s back in and went back to 7psi just because I was more comfy with it. I guess this doesn't really help with your problem, just something to think about. good luck with it.
 

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Do the old Barry grant one gallon gas can test at both of your pressures. See how long it takes to fill a one gallon gas can. Post your results.
 

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Discussion Starter #8
did the 0ne gallon test.just put both carb lines in a [email protected] 6.5psi it looks like 27 seconds to get a gallon @ 7.5 psi it was closer to 23 seconds.last time out car went 10:19 et at old setting 8.5psi..with the lower psi i needed to raise float levels.this is what i think the problem was at 6.5. set it @ 7 psi ,put new plugs in it but it has rained for the last 2 days..we'll see...thanks...are those numbers far off? or make sense..
 
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