Holley 670 SA tuning
#989625
05/10/11 04:22 PM
05/10/11 04:22 PM
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Joined: Feb 2008
Posts: 992
Simi Valley, CA
MoparJ
OP
super stock
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OP
super stock
Joined: Feb 2008
Posts: 992
Simi Valley, CA
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I have a 670 Holley Street Avenger on my XE268 cammed 318 with headers, 3000 stall, and 3.55s. Currently, it is running best with 69 jets in the front, 73 in the rear and one of, if not, the lightest secondary spring that I have in my collection. This card comes stock with a 6.5 power valve. It pulls without stumble to 5800 rpm, but I still have an initial bog when I first mash the pedal.Should I bump the power valve up a bit to help alleviate this?
2016 Ram 1500 Crew Cab: 5.7, 65RFE, 4.56 gears with locker, Hemifever tuned, AFE intake, 87mm throttle body, JBA headers, 3" Flowmaster exhaust, split to dual 2.5" exits. 13.57 best ET so far.
Searching for new A or B Body Project!
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Re: Holley 670 SA tuning
[Re: MoparJ]
#989626
05/10/11 04:28 PM
05/10/11 04:28 PM
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Joined: Feb 2005
Posts: 5,221
Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
I have a 670 Holley Street Avenger on my XE268 cammed 318 with headers, 3000 stall, and 3.55s. Currently, it is running best with 69 jets in the front, 73 in the rear and one of, if not, the lightest secondary spring that I have in my collection. This card comes stock with a 6.5 power valve. It pulls without stumble to 5800 rpm, but I still have an initial bog when I first mash the pedal.Should I bump the power valve up a bit to help alleviate this?
You put in the lightest spring? That was your 1st. mistake, don't go to extreams, 1 step at a time, I'm sure you have a lean bogg, try the natual spring or what ever came in it 1st., then change them to the next one, either lighter or heavier.
Last edited by joedust451; 05/10/11 04:30 PM.
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Re: Holley 670 SA tuning
[Re: joedust451]
#989627
05/10/11 04:45 PM
05/10/11 04:45 PM
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Joined: Feb 2008
Posts: 992
Simi Valley, CA
MoparJ
OP
super stock
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OP
super stock
Joined: Feb 2008
Posts: 992
Simi Valley, CA
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Quote:
Quote:
I have a 670 Holley Street Avenger on my XE268 cammed 318 with headers, 3000 stall, and 3.55s. Currently, it is running best with 69 jets in the front, 73 in the rear and one of, if not, the lightest secondary spring that I have in my collection. This card comes stock with a 6.5 power valve. It pulls without stumble to 5800 rpm, but I still have an initial bog when I first mash the pedal.Should I bump the power valve up a bit to help alleviate this?
You put in the lightest spring? That was your 1st. mistake, don't go to extreams, 1 step at a time, I'm sure you have a lean bogg, try the natual spring or what ever came in it 1st., then change them to the next one, either lighter or heavier.
I had the heaviest spring in previously, which the carb had in it when it came off of another motor. It had a horrible bog. I progressively stepped down to the current sprint, which has given the best results. The bog is ever so slight and it pulls well in all other ranges. Heavier springs were progressively worse.
I NEVER go to extremes, as I dont have the resources to fix breakages caused by doing so.
For the record, this is in a Duster.
2016 Ram 1500 Crew Cab: 5.7, 65RFE, 4.56 gears with locker, Hemifever tuned, AFE intake, 87mm throttle body, JBA headers, 3" Flowmaster exhaust, split to dual 2.5" exits. 13.57 best ET so far.
Searching for new A or B Body Project!
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Re: Holley 670 SA tuning
[Re: 71TA]
#989629
05/10/11 10:19 PM
05/10/11 10:19 PM
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Joined: Jan 2003
Posts: 5,791
Hamilton, Ontario Canada
Magnum
master
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master
Joined: Jan 2003
Posts: 5,791
Hamilton, Ontario Canada
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If you swapped the secondary spring and it made no change. Your bog may be from the primary side. Had a similar bog but mine was only from a super quick application of throttle. Just a quick application was no bog. Have your read this thread?
69 Super Bee, 93 Mustang LX, 04 Allure Super
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Re: Holley 670 SA tuning
[Re: 71TA]
#989630
05/11/11 12:56 AM
05/11/11 12:56 AM
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Joined: Feb 2005
Posts: 5,221
Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
Heres the trick. Take a long strand of solid copper wire. some small stuff like .015" to .020" dia. Like telephone wire. Sure Radio Shack would have something like this.
THEN cut 2 pieces about 8" or so long. Stick one in each of the idle air bleeds (1 in the picture). See how it runs. I had to stick 2 wires in each of mine and the bog was GONE - verified with an LM1 air fuel ratio meter and an O2 sensor in my headers.
The reason for 8+" long is so you can loop most of it over the air hoorn (only about 1/2" or so will go into the bleed)and either tape down or sandwich between the carb body and air cleaner to hold it in place like I did.
So may people play with pump shot, squiter hole, vac spring, etc and thats NOT the problem. these things are TOO LEAN from the factory. After my run in with these low end carbs that you can only replace the main jets I will ONLY buy a carb that you can replace everything. But you need the right tools like an a/f ratio meter to see whats happening. Checking the plug color or seat of the pants in just not good enough.
You do realize the Inner bleeds are Highspeed right? I notice you have #1 & 2 on the graph, Might be better off doing it on the primary side 1st., I do this trick all the time on my holleys, works like a charm, & you don't necassarily have to change pump cams & squirters, just fatten up the idle curcuit a bit. Even the newer DPers are leaned out on the idle curcuit from what they used to be, My 4777-7 650dp had .086"F/.055"R IABs from the earlier models that were around .074"F/.040sR, they did however increase the IFRs to .035", No more burning the eye balls, I had the mix screws out around 3 turns each, ran great.
I forgot about that Magnum, Yeah he had issues wiuth the pump arm being sloppy (some come through like this  ), shimmed it up & blammmm. & wouldn't you know it, ran great on the factory squirter/cam
Last edited by joedust451; 05/11/11 01:05 AM.
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Re: Holley 670 SA tuning
[Re: Jeremiah]
#989632
05/11/11 05:34 PM
05/11/11 05:34 PM
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Joined: Feb 2008
Posts: 992
Simi Valley, CA
MoparJ
OP
super stock
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OP
super stock
Joined: Feb 2008
Posts: 992
Simi Valley, CA
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To further clarify, if i ease into it, there is no bog. Only when I mash it real quick and only briefly. Just falls on its face for a brief second before the power really comes back on. Not bad at all, just fine tuning.
2016 Ram 1500 Crew Cab: 5.7, 65RFE, 4.56 gears with locker, Hemifever tuned, AFE intake, 87mm throttle body, JBA headers, 3" Flowmaster exhaust, split to dual 2.5" exits. 13.57 best ET so far.
Searching for new A or B Body Project!
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Re: Holley 670 SA tuning
[Re: joedust451]
#989633
05/12/11 02:09 PM
05/12/11 02:09 PM
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Joined: Jan 2003
Posts: 5,791
Hamilton, Ontario Canada
Magnum
master
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master
Joined: Jan 2003
Posts: 5,791
Hamilton, Ontario Canada
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Quote:
I forgot about that Magnum, Yeah he had issues wiuth the pump arm being sloppy (some come through like this ), shimmed it up & blammmm. & wouldn't you know it, ran great on the factory squirter/cam
My fix is not to solve a sloppy pump arm. If it's sloppy, it's either bent or out of adjustment.
The fix is to effectively make the spring stronger. Resisting the pressure when you try to force the fuel out of the accelerator pump quickly.
69 Super Bee, 93 Mustang LX, 04 Allure Super
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Re: Holley 670 SA tuning
[Re: 71TA]
#989635
05/12/11 07:50 PM
05/12/11 07:50 PM
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Joined: Mar 2003
Posts: 9,100
Rogue River, OR
Jeremiah
master
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master
Joined: Mar 2003
Posts: 9,100
Rogue River, OR
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I didn't take the time to weld a bung on my '70 PW to check the a/f. That is a fact. I did fix my problem even if I did it the wrong way. That said it's on my list to try what you suggested on the carb in my truck. If it helps I'll decrease the pump shot and report back. If need be I'll tap the main body for 10-32 screw in air bleeds. Does that sound better to you?  edit: With the other hp style carbs I have they generally need to have the idle circuit leaned out a ton due the altitude here in K Falls (~4200 ft).
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Re: Holley 670 SA tuning
[Re: MoparJ]
#989636
05/14/11 09:03 AM
05/14/11 09:03 AM
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Joined: Jul 2007
Posts: 531
Virginia
JimG
mopar
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mopar
Joined: Jul 2007
Posts: 531
Virginia
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Based on what I've read here, you don't yet know if the bog is primary or secondary related.
A lighter spring would increase the likelihood of a bog when the secondaries open (as previously mentioned). That part is confusing.
I'd like to see you go back to a stiff secondary spring and confirm that the bog gets worse. I cant see from your post that you changed more than one thing at a time, but I'm really suspicious that a lighter spring improved a bog. Coincidence perhaps?
Last edited by JimG; 05/14/11 09:07 AM.
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