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Discussion Starter · #1 ·
I've got a 600cfm holley that i purchased as rebuilt but I'm having a prob with it

its running very rich i believe as it stings my eves and smells real bad
also on tick over as you accelerate it does not pick up well

ive screwed in the 2 little screws and it runs worse but still stinks and hurts my eyes

i do not have access to a co2 meter

any help would be great please
 

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Compulsive chicken choker
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Darren, I had tried two Holley 600's on my previous car ('60 Impala) and had nothing but grief with both exactly as you describe. In the end I fitted an inline fuel regulator and gauge to prevent it over-fueling.
 

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I bough mine off EBay, it was a simple adjustable regulator that had a screw in the top to adjust the pressure with a gauge installed straight after. I can't remember the ideal pressure for a Holley but it is quite low. It would be worth sending a pm to Adam as he always had good suggestions for getting a SBC to run right.
 

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Be careful with some of the EBay Chevy stuff, the quality is at best questionable. Send a PM to Adam Sayers before buying anything, he's a helpful chap that will help you solve the problem without wasting money. I'll try and find a picture of the regulator I used.
 

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nothing to do with the regulator, the float bowl needle valve will hold between 9-11 psi. If the fuel pressure was too high it would overcome these valves and be flooding the motor constantly, fouling plugs or stalling it. It's a good idea to run one and know you fuel pressure using a low pressure gauge ie 0-15ps1, not 0-125psi. Some more info on your pump would help, a carb of this size shouldn't need a huge bypass pump, an dead head system should be adequate.

Forget the idle screws, they are for very fine idle adjustment once the base settings are sorted.

Your issue will lie with either your power valve which screws into the metering block, between float bowl and main body or the vacuum secondary opening rate, the canister on the side, in there is a spring and diaphragm which operate based on engine vacuum .

Buy a vacuum gauge, this will tell you everything you need to know. From that point you simply tune the carb to the vacuum signal by referencing and installing the correct power valve and VS spring for the vacuum your engine is pulling. Primary jetting (assuming you have primary metering block and not the plate type) can be altered and tuned by road testing, same with secondary jetting but get the thing idling and not fouling plugs first then tune it

Any stumbles or hesitation can be worked out thereafter with a change to the accelerator pump shot shooter size and clearance. Feel free to PM for help once you have a vacuum reading.
 

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I really don't get it when people say 'It's rich because it's stinging my eyes'. Please remember that if you had 6 minis idling in your garage your eyes would sting fairly but that doesn't necessarily mean they are running rich. I would think that a 600 cfm holley is only just big enough for a 350 cube motor if the motor is stock. If it's been 'built' I'm sure it won't be big enough. I needed a 750 on my pontiac 350 to get anywhere near enough.
 

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Discussion Starter · #15 ·
I really don't get it when people say 'It's rich because it's stinging my eyes'. Please remember that if you had 6 minis idling in your garage your eyes would sting fairly but that doesn't necessarily mean they are running rich. I would think that a 600 cfm holley is only just big enough for a 350 cube motor if the motor is stock. If it's been 'built' I'm sure it won't be big enough. I needed a 750 on my pontiac 350 to get anywhere near enough.
i have a 5.0l std engine in it mate
 

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Discussion Starter · #16 ·

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Darren, I borrowed another good 600cfm from Capt Pugwash (Thanks Kev!!) and tried it on mine, just to check. Can you get one to try out? It that one works OK, set yours up the same.
 
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