1967 330 poor aceleration

Thread Tools
 
Search this Thread
 
Old Aug 1, 2015 | 02:35 PM
  #1  
nj67's Avatar
Thread Starter
Registered User
 
Joined: Jun 2014
Posts: 170
From: Behind the Wheel
1967 330 poor aceleration

I have a 1967 Cutlass Holiday coupe with it's original 330 showing 79,000 miles which I believe to be accurate by the documentation I got with the car. It has a Holly Carb which I think is a 650 see attached photo's. I drive the car often and on long trips very reliable and runs well but from a dead stop it feels a little sluggish and if I do put the pedal to the floor on take off I get a small bog before acceleration. I did the timing last night with a new timing light that has a dial, before I touched anything it was at 10B at idle with vacuum advance disconnected. I ran it at 3,000 rpm and adjusted to 32 which gives me 12b at idle sitting with no load the throttle response seems better and idle is smooth at 800 rpm. I took it for a short test ride and it has almost no noticeable difference off the line. I am not sure what gears I have in rear but I believe they must be 2.78, at 80 mph I am at 3,000 rpm car has good acceleration at higher speeds and pulls strong. The original trans has been swapped for TH350, there is no detent cable hooked up presently and I noticed previous owner has the vacuum hooked to ported vacuum. I am going to re route to manifold not sure if it makes a difference but I remember reading that is where it belongs. It has newer plugs, cap, wires, rotor and points. It will chirp tires first to second with out much effort so everything seems good except from dead stop.
Attached Images
File Type: jpg
20150731_185443.jpg (1.06 MB, 36 views)
File Type: jpg
20150731_185503.jpg (1.27 MB, 29 views)
Old Aug 1, 2015 | 02:41 PM
  #2  
oldcutlass's Avatar
Administrator
 
Joined: Oct 2009
Posts: 42,506
From: Poteau, Ok
The trans needs manifold vacuum. A detent cable will allow you to get your passing gear to work. With a 2-something gear ratio you are not going to get the neck snapping acceleration you want.
Old Aug 1, 2015 | 02:59 PM
  #3  
nj67's Avatar
Thread Starter
Registered User
 
Joined: Jun 2014
Posts: 170
From: Behind the Wheel
Originally Posted by oldcutlass
The trans needs manifold vacuum. A detent cable will allow you to get your passing gear to work. With a 2-something gear ratio you are not going to get the neck snapping acceleration you want.

I know im not going to get neck snapping but I think it should be better and what would cause the bog if I do floor it from dead stop lack of gas to much gas or?
Old Aug 1, 2015 | 04:43 PM
  #4  
M-14's Avatar
Registered User
 
Joined: Dec 2012
Posts: 162
Peer down in the carb while you cycle the throttle linkage, engine off of course, is there a strong shot of fuel? There should be. The acceleration pump is responsible for this.

Last edited by M-14; Aug 1, 2015 at 04:53 PM.
Old Aug 1, 2015 | 05:23 PM
  #5  
nj67's Avatar
Thread Starter
Registered User
 
Joined: Jun 2014
Posts: 170
From: Behind the Wheel
Originally Posted by M-14
Peer down in the carb while you cycle the throttle linkage, engine off of course, is there a strong shot of fuel? There should be. The acceleration pump is responsible for this.

I will check tomorrow, I almost never floor the car from a dead stop I treat it with respect and want it to stay in good shape but I also want it running to it's full potential.
Old Aug 1, 2015 | 08:24 PM
  #6  
young olds's Avatar
Registered User
 
Joined: Mar 2010
Posts: 2,049
From: Mt Vernon,WA
usually if you have a bog when flooring it your secondaries arent open at the right time, either to soon or to late but dont recall which
Old Aug 3, 2015 | 11:02 PM
  #7  
64Rocket's Avatar
Registered User
 
Joined: Sep 2006
Posts: 2,384
From: Union City Calif.94587
What gear ratio do you have in the rear ?

2.41 or 2.67 gears are not good for acceleration.
cruising at 80 mph, they are great.

3.08 will be a world of difference, but will hinder 85 mph free way driving.

Gene
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
auto_editor
Body & Paint
2
Dec 5, 2010 02:05 PM
patmills
Brakes/Hydraulic Systems
11
Aug 15, 2010 07:15 PM
Shebe72
Cutlass
10
Jul 5, 2010 08:11 AM
55jes
General Questions
5
May 13, 2010 08:36 PM
DAN76
Brakes/Hydraulic Systems
6
Jul 28, 2009 02:13 AM




All times are GMT -7. The time now is 10:37 PM.