Results 1 to 2 of 2

Thread: Holley 4150 Quick Fuel Vacuum Problem

  1. #1

    Default Holley 4150 Quick Fuel Vacuum Problem

    Hi. Barnsydog, United Kingdom. I have a 502 BB Chevy that was fitted with a 871 Blower in a Glass 34 3 Window. Too quick for the street, so I removed the Blower setup. I fitted a Torker type Manifold (new) and a 780 cfm Quick Fuel Street/Strip Vacuum Secondary Spread-bore carb. The vacuum secondary won't open. I've changed diaphragm. I'm told the Silver spring may be too strong. Any ideas? It's running very rough idle slightly better when warm. The Cam is Isky lift .340" .358" can anyone help?

  2. #2
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,531

    Default

    How do you know the secondaries aren't opening?
    Does it have the adjustable secondary opening rate screw?
    If the engine was built for a blower, the cam & compression ratio
    is probably not what you want for normally aspirated now.
    Your Quick Fuel carb is also a square bore, not a spread-bore.
    Regards, Gary

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us