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Double07

New SBF 302 Datsun owner

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Hi all! 

 

I just picked up a 75 280z with a SBF 302 from an elder retired guy who did not know much about the car. The body is flawless but the engines running a bit rough with the 4 barrel edlebrock. It idles great but bogs down at WOT. Any tips on dialing in the carbs?

 

 

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Here are a few suggestions based on the Edelbrock I have on my 351. I have had all these issues in the past with many different engines.  

1.  These carbs have a weighted plate over the secondaries to allow air to the secondaries only if there is sufficient air flow to pull it open.  Check to see if this plate moves freely.

2.  The metering rods restrict fuel flow at low rpm of high vacuum.  These can be removed from the top with the carb in place.  See that these are clean and move freely.  

3.  You might also check the timing.  If the centrifugal weights are stuck you may not be getting enough advance at high rpm.  I like to see 25 to 30 degrees total advance at approximately 2500 rpm.  

 

I hope this helps

Brad

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Don't waste your time and money on an Edlebrock. 

 

 

Replace the Edelbrock with a Holly Street Avenger:

 

  • Amazing off-idle throttle response compared to the Edelbrock.
  • Excellent  response from idle to full throttle.
  • Easy to set up vacuum  secondaries with simple spring replacement.
  • Visual float setting with carb installed.

 

My 240Z: SBC 350

 

I replaced the Edelbrock with a 570 CFM Holley Street Avenger carb approx eight years ago. The only modification I made was to add (simple) stiffer springs in the vacuum secondary control module to delay onset of the secondaries opening. 

 

 

Holley 570 Instructions.pdf

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I'd at least waste SOME time on the Edelbrock unit before throwing $$ at it and going over to a Holley.  I have an Edelbrock on my 351w right now, and when I got it linkages were seized up, metering rods were stuck, it was a mess. Got a $30 rebuild kit, and took my time setting float height etc, went through a bunch of PB Blaster getting things moving again, but y'know what, it runs great now. Fires right up, no bogs, etc.

 

585Z had great advice, I was actually going to suggest a few of those points myself. 

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Usually firing up is not an issue. She’ll fire up immediately. I run into issues up too. The car definitely does run strong at all. I think I have some timing issues as well. 

 

Thansk for all all the advice. I might spend give the rebuild kit a try. 

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