© Copyright 1995 thru 2008 - The Mustang Works™. All Rights Reserved.
MustangWorks.com is designed and hosted by Aero3 Media.
MustangWorks.com is designed and hosted by Aero3 Media.
06-17-2006, 09:10 AM | #21 |
Registered Member
Join Date: Oct 1998
Location: Az
Posts: 854
|
Re: Holley carb. gurus needed!
BTW, whats the idle vac. and what power valve do you have?
__________________
84 convt,roller 302,AFR's, performer 3.55's, underdrives BBK shorties stock cam, 1.7's 13.58@102.84 and a '68 stang .. project 8 sec street car... 557 big block + N20 :-) http://members.cox.net/darkknight302/68nwrear.jpg |
06-17-2006, 02:15 PM | #22 |
Import Slayer
Join Date: May 1999
Posts: 2,241
|
Re: Holley carb. gurus needed!
Idle vacuum is between 14-15hg(Park) and I'm running a 6.5 power valve.
I'm beginning to wonder if maybe my PV is closing before the end of the run and shutting off the power circuit of the carb. I have a vacuum gauge I'm going to hook up so I can watch it during a pass down the track.
__________________
'82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator. |
06-17-2006, 02:30 PM | #23 | |
Registered Member
Join Date: Nov 1998
Location: Houston, Tx.
Posts: 3,887
|
Re: Holley carb. gurus needed!
Quote:
Remember that it's when the manifold vacuum is below the rating that the power valve is open. At WOT, the vacuum is right at 0 or a hair more. No matter what pwer valve # you use, it will always be open at WOT. Rev
__________________
'66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe |
|
06-17-2006, 03:59 PM | #24 |
Rat Killer
Join Date: Aug 2002
Location: Cold ass Ohio
Posts: 1,143
|
Re: Holley carb. gurus needed!
There is absolutely NO WAY I would start playing with transfer slots, and drilling holes in the butterflies until I got the idle screw issue figured out.
I'm with Brian on this one, that motor isn't going to want to idle much below 950 rpm at best, if that's where she's happy, then that's where she needs to be. You may however find that changes once you get your issue figured out. Exactly which carb are we talking about? Some models, that screw adjusts the air/fuel mixture for the idle circuit, on other it does not. TRUST ME, read on. On MY carb, those screws did squat for air/fuel ratio. That is determined internally, all those screws did was adjust the AMOUNT of air/fuel that got fed through the idle circuit. Yes, I learned that in the book too. heehehe Brian, we need to make you a "book on tape" so you can listen to it on your way to work! hehehehehe
__________________
d-Con Racing "Nothing fancy, just 347 inches of RAT POISON!" MICE need not apply..... |
06-17-2006, 05:24 PM | #25 | |
Import Slayer
Join Date: May 1999
Posts: 2,241
|
Re: Holley carb. gurus needed!
Quote:
According to the book, you're supposed to find a PV rating that will remain closed at idle yet high enough to stay open during acceleration periods(drag racing) My Holley is a 750dp(4150). Only a vacuum gauge will tell you exactly what PV you really need without the "guess" work.
__________________
'82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator. |
|
06-17-2006, 08:56 PM | #26 | |
Registered Member
Join Date: Nov 1998
Location: Houston, Tx.
Posts: 3,887
|
Re: Holley carb. gurus needed!
Quote:
Rev
__________________
'66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe |
|
06-17-2006, 09:21 PM | #27 | |
Registered Member
Join Date: Nov 1998
Location: Houston, Tx.
Posts: 3,887
|
Re: Holley carb. gurus needed!
Quote:
Rev
__________________
'66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe |
|
06-18-2006, 02:40 PM | #28 | |
Import Slayer
Join Date: May 1999
Posts: 2,241
|
Re: Holley carb. gurus needed!
Quote:
It works with them all the way in. I know it's not supposed to be that way but unless it's hurting performance, I'll just keep them there because I KNOW if I start screwing around with this carb and doing things I'm unsure about then I'll end up with a nice paper weight and buying ANOTHER carb. I'm lucky I was able to swap jets and have it still function afterwards.
__________________
'82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator. |
|
06-19-2006, 06:51 AM | #29 |
Registered Member
Join Date: Oct 1998
Location: Az
Posts: 854
|
Re: Holley carb. gurus needed!
How much timing are you running? Advancing the initial timing will increase idle speed and allow you to back off the idle speed screw on the carb.
__________________
84 convt,roller 302,AFR's, performer 3.55's, underdrives BBK shorties stock cam, 1.7's 13.58@102.84 and a '68 stang .. project 8 sec street car... 557 big block + N20 :-) http://members.cox.net/darkknight302/68nwrear.jpg |
06-19-2006, 10:44 AM | #30 |
Import Slayer
Join Date: May 1999
Posts: 2,241
|
Re: Holley carb. gurus needed!
I have 36* total timing but 1000rpms is 1000rpms no matter how you arrive at it. If the engine wants to idle at 1K, it's not going to care if you got it by advancing the initial or turning the idle speed screw.
__________________
'82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator. |
06-19-2006, 10:54 AM | #31 |
Registered Member
Join Date: Oct 1998
Location: Az
Posts: 854
|
Re: Holley carb. gurus needed!
You need to read the holley book... It DOES matter. If the throttle blades are opened up enough to be into the main or transition circuit, then the idle mixture screws wont do crap. If you can keep the idle speed up with a timing change and lower the idle speed screw so that the blades arent open as far, the idle mixture screws will work better.
Maybe you should take it to someone and have THEM tune it
__________________
84 convt,roller 302,AFR's, performer 3.55's, underdrives BBK shorties stock cam, 1.7's 13.58@102.84 and a '68 stang .. project 8 sec street car... 557 big block + N20 :-) http://members.cox.net/darkknight302/68nwrear.jpg |
06-19-2006, 11:09 AM | #32 | |
Import Slayer
Join Date: May 1999
Posts: 2,241
|
Re: Holley carb. gurus needed!
Quote:
__________________
'82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator. |
|
06-19-2006, 01:16 PM | #33 |
Registered Member
Join Date: Apr 2001
Location: Staging lane
Posts: 4,337
|
Re: Holley carb. gurus needed!
LMAO!!!
And people say they run carbs cause they like things simple.
__________________
92' LX-Big brakes, Lots and lots of suspension, GT40X heads, Ported cobra intake, stock cam, Vortech SC trim. 00' Lightning-Stock 88'CRX-13 second ego killer |
06-19-2006, 07:04 PM | #34 |
Registered Member
Join Date: Nov 1998
Location: Houston, Tx.
Posts: 3,887
|
Re: Holley carb. gurus needed!
Carbs are pretty simple if you take them circuit by circuit and undertstand how a change in one circuit might affect the other circuits. They all have to work together for the engine to run well.
Rev
__________________
'66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Calling Jester and all Carb guru's | rwhite65 | Windsor Power | 7 | 09-23-2005 10:38 AM |
Holley Carb | Hitman73 | Classic Mustangs | 15 | 07-18-2005 06:35 PM |
this carb adapter plate for a straight six goes to which holley 2 barrelcarb | daccrow86 | Classic Mustangs | 0 | 09-23-2003 10:23 AM |
850 cmf holley race carb. | 69fastback | Classic Mustangs | 0 | 12-21-2001 12:13 AM |
650 DP Holley Carb on 390 | RedLilPony | Classic Mustangs | 12 | 03-08-2001 02:34 PM |