accel pump: which hole?

Thread Tools
 
Search this Thread
 
Old Apr 11, 2020 | 08:03 PM
  #1  
irydasteelhorse's Avatar
Thread Starter
Registered User
 
Joined: Feb 2012
Posts: 49
From: billings mt
accel pump: which hole?

i have a bone stock 67 supreme, 330, (2spd)

auto. trying to get a few small details dialed in. question i have is: theres two holes for the linkage of the accel pump. which hole is correct for my car. i was told one was for auto car and one was for stick?
Old Apr 13, 2020 | 05:34 AM
  #2  
TripDeuces's Avatar
Registered User
 
Joined: Jun 2010
Posts: 3,613
From: Rogues Island, USA
Stick or auto is incorrect. I believe the difference is the pump duration and whether it comes in up front or is a slower shot. Use the #1 hole and set the pump clearance with that.
Old Apr 13, 2020 | 06:00 PM
  #3  
matt69olds's Avatar
Registered User
 
Joined: Jan 2010
Posts: 6,099
From: central Indiana
I’m guessing you can see wear marks on the pump arm from where the linkage was? If not, the inner hole gives the bigger pump shot, due to the pump arm starting at a higher point of travel. However, like so many things in life, bigger inst alway better (Ha!) if the engine gets enough pump shot with the outer hole, then the bigger shot is wasted fuel. Try it both ways
Old Apr 13, 2020 | 08:27 PM
  #4  
Ozzie's Avatar
Registered User
 
Joined: May 2009
Posts: 1,614
From: S.E. Louisiana, so far still in U.S.A.
It's probably best to specify the model of the carburetor if possible. If the model number isn't available, next best is to say if it's a 2GC or a 4MV.
Old Apr 14, 2020 | 05:37 AM
  #5  
joe_padavano's Avatar
Old(s) Fart
 
Joined: Mar 2007
Posts: 50,791
From: Northern VA
Each Qjet carb is calibrated for it's original application. The two holes in the pump arm are part of that calibration process. The inner hole will provide more pump stroke for a given amount of throttle movement and typically that is the one that is used. You still need to correctly adjust the pump height per the specs for your carb.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Cpriester123
General Discussion
4
Nov 29, 2016 04:50 AM
mzbk2l
General Discussion
1
Feb 24, 2014 04:44 PM
diesel olds
Big Blocks
4
Nov 6, 2013 03:39 PM
MDchanic
Big Blocks
5
Mar 25, 2013 05:01 AM
dancutlass
Small Blocks
3
May 2, 2012 02:14 PM




All times are GMT -7. The time now is 08:52 AM.