Fuel pressure

[CRUZE 418]

How much fuel pressure will a Holley handle? I have had a problem trying to get a handle on my Sixpack jetting. Lean just driving around, stand on it and black plugs.
That's with stock metering plates in the end carbs. Finally got an inline fuel pressure gauge and I have 10 lbs. I am using the Carter M 6270 pump. It's the only pump that with stock type ports for a say '69 or '70. So I need to regulate down to 5 or 6 right?

 

[Hellrats]

5 to 7 psi

 

[TT5.9mag]

Holley needles will handle 7-10 psi but are finicky if you don’t have a good filter. But don’t assume you have a problem with pressure if you don’t have one. Is there fuel dribbling out of the boosters at idle? Yes? You have too much fuel pressure and it’s pushing past the needles. No? The needles are working and you have other tuning problems. If you’re lean at idle you likely don’t have pressure problems. Get the main jetting sorted out for cruise afr and tune the power valve (and pv channel restrictors) for WOT throttle afr.

 

[CRUZE 418]

Thought that I could half *** tune, this Sixpack really has just kicked my *** . Will have to check the boosters leaking, bit I don't think so.

 

[TT5.9mag]

Are your outboard carbs progressive? If so I’d close them up tight and disconnect the linkage. Tune the center carb for all of your idle and off idle transitioning. Get wot on the center only close with pv tuning. Then bring in the outboards and jet them to maintain your wot afr.

 

[CRUZE 418]

Vacuum outboards. I have tried tuning for idle with the center carb, but as you know, it idles off all three. The frt outboard carb really seems to be the gorilla, #1, being lean and having to richen. It's te.p with a temp gun is low. In a leak down comp test, it's my best cyl.
Will try some of this and get back with you.