Sunday drive

Thread Tools
 
Search this Thread
 
Old Mar 20, 2011 | 10:41 AM
  #1  
panos's Avatar
Thread Starter
Registered User
 
Joined: Aug 2009
Posts: 314
From: Sweden
Sunday drive

A short blast after i installed the 300+ ignition box, rejetted the carb and adjusted timing,only problem that i have is that i cant attach th vacuum advance because strange things happens like it shoots from the exhaust at part throttle so i left it out for now,base timing is 12btdc and total 30btdc at 3000rpm.

http://www.youtube.com/watch?v=VhvY757AhCs
Old Mar 20, 2011 | 01:47 PM
  #2  
citcapp's Avatar
Registered User
 
Joined: Nov 2007
Posts: 9,127
From: Rathdrum, Idano
Very cool, do you have the vacuum advance connected to ported vacuum at the carb or to manifold vacuum. Should be to ported vacuum at the carb
Old Mar 20, 2011 | 01:54 PM
  #3  
panos's Avatar
Thread Starter
Registered User
 
Joined: Aug 2009
Posts: 314
From: Sweden
Originally Posted by citcapp
Very cool, do you have the vacuum advance connected to ported vacuum at the carb or to manifold vacuum. Should be to ported vacuum at the carb
I had it on manifold vacuum,i can try ported but im a little afraid that is gonna ping,this motor doesnt seem to like too much advance
Old Mar 20, 2011 | 02:32 PM
  #4  
citcapp's Avatar
Registered User
 
Joined: Nov 2007
Posts: 9,127
From: Rathdrum, Idano
Try the ported and let us know what happens, may have to change the spring rates in the distributor
Old Mar 20, 2011 | 03:09 PM
  #5  
71 Cutlass's Avatar
One of None W-31
 
Joined: Jul 2009
Posts: 671
From: Texas
interesting video on ported vs manifold vacuum. Old timer says always use manifold vacuum not ported b/c that's the way all muscle cars were always done until "Emssion engines" requirements were placed on engines.

http://www.youtube.com/watch?v=Gj2ut...BD20013E579A63

Start at 40 second mark.
Old Mar 20, 2011 | 06:45 PM
  #6  
Lady72nRob71's Avatar
Registered User
 
Joined: Feb 2008
Posts: 11,798
From: Plano, TX
Mine is 'improperly' set on manifold vac but she runs too good to move anything....
Old Mar 20, 2011 | 08:55 PM
  #7  
71 Cutlass's Avatar
One of None W-31
 
Joined: Jul 2009
Posts: 671
From: Texas
Originally Posted by Lady72nRob71
Mine is 'improperly' set on manifold vac but she runs too good to move anything....
Or, "properly" set up as the guy in the video believes.
Old Mar 21, 2011 | 12:59 AM
  #8  
panos's Avatar
Thread Starter
Registered User
 
Joined: Aug 2009
Posts: 314
From: Sweden
Originally Posted by 71 Cutlass
Or, "properly" set up as the guy in the video believes.
That is a big debate that is going on for years,im for manifold but thats just me,maybe it depends on the motor? who knows,but just a question as we all know when you set your initial you have to unplug the vacuum right? if the right way is ported vacuum why should you do that? there is no vacuum at idle on the ported side and it doesnt change a thing since the throttle blades are closed
Old Mar 21, 2011 | 05:09 AM
  #9  
Lady72nRob71's Avatar
Registered User
 
Joined: Feb 2008
Posts: 11,798
From: Plano, TX
Originally Posted by 71 Cutlass
Or, "properly" set up as the guy in the video believes.
Right!
I created a debate on this point several years ago.
Most of the "old timer" mechanics said to use manifold vac. I knew their collective experience must say something.
I think there are a little less emissions when used on ported vac (or something like that).
Old Mar 21, 2011 | 08:03 AM
  #10  
panos's Avatar
Thread Starter
Registered User
 
Joined: Aug 2009
Posts: 314
From: Sweden
Here is an intresting article

https://classicoldsmobile.com/forums...tml#post247099
Old Mar 21, 2011 | 09:10 AM
  #11  
71 Cutlass's Avatar
One of None W-31
 
Joined: Jul 2009
Posts: 671
From: Texas
I've posted that article here before as well. Just another confirmation that cars have used full manifold vacuum, until the gov. wanted less emissions polluting the air (1973 or so) so ported vacuum was mandated by the gov. Ported vacuum is about polluting the air less, not the performance of a vehicle.
Old Mar 21, 2011 | 09:35 AM
  #12  
cutlassefi's Avatar
Registered User
 
Joined: Nov 2008
Posts: 8,477
From: Central Fl
I disagree. If your distributor is curved correctly then the vacuum advance is solely to optimize the spark timing for light load cruise for the most part.
Even on my EFI at normal operating temp the spark map reflects an increase in timing at cruise only. However there are benefits by being able to add spark for cold running as well as removing it at various loads and rpms here and there.
Old Mar 21, 2011 | 05:30 PM
  #13  
ziff396's Avatar
Registered User
 
Joined: Jun 2008
Posts: 1,015
From: Near Muskegon Michigan
Mine hates ported vacume. I have to really crank up the idle for it to run, and still is to rough. Plug into manifold vacume and it runs great. Aftermarket cams etc. change alot of things. I'm set up @17 degrees initial and 37 all in @ 3k. Edelbrock heads. Lunati Vodoo 60803. From what I have heard and have found, Edelbrocks like a lot of timing. Actually @20 degrees initial it starts at almost the bump of the key, however, I am not that brave to leave it that far ahead. No ping to date. JMO. EFI, I respect your experience. Just had to add mine with my engine.
Old Mar 21, 2011 | 07:50 PM
  #14  
71 Cutlass's Avatar
One of None W-31
 
Joined: Jul 2009
Posts: 671
From: Texas
I'll stick with what works best...and with the old timers who lived "back in the day."
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
RetroRanger
Small Blocks
42
Sep 14, 2013 06:16 PM
Kennybill
The Clubhouse
2
Jul 16, 2009 06:45 PM
65az
General Discussion
7
Mar 30, 2009 11:26 AM
Oldsmaniac
Other
9
Nov 22, 2008 06:01 AM
$tryker
Cutlass
5
Jun 11, 2008 02:55 PM




All times are GMT -7. The time now is 07:52 AM.