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Re: Holley 4 corner idle questions? [Re: HotRodDave] #534590
11/27/09 11:14 PM
11/27/09 11:14 PM
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Indiana
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YO7_A66 Offline
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""It ran fine with the 770 street avenger and I swapped the carbs back for a minute just to make sure something didn't happen in the swap and it was OK again. ""

Can someone confirm what the stock jetting is on a 770 SA?
86 square jets seem very rich for a 9.0:1 360 with a XE268 cam.

""OK so now it idles fine but it runs like crap every where else in the RPM range.""
""The problem is holding at a steady RPM it breaks up real bad and smells rich""

It appears that you have the idle circuit dialed in now but the jetting is way too fat causing it to run that bad. Even though it is an 830cfm, I would suggest trying much smaller primary jets and give it another test drive. Maybe 72-74 primary jets (since you have a power valve on the primary side) and stay out of the secondaries until you get a feel for the new jets.


Last edited by YO7_A66; 11/27/09 11:29 PM.
Re: Holley 4 corner idle questions? [Re: YO7_A66] #534591
11/28/09 12:17 AM
11/28/09 12:17 AM
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Kalispell Mt.
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HotRodDave Offline OP
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72 and 75 in the street avenger.

Can I just use those jet sizes in the 830 and get it close? I would think it would need more jet to go with more air flow


I am not causing global warming, I am just trying to hold off a impending Ice Age!



Re: Holley 4 corner idle questions? [Re: HotRodDave] #534592
11/28/09 12:36 AM
11/28/09 12:36 AM
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Romeo MI
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Quote:

72 and 75 in the street avenger.

Can I just use those jet sizes in the 830 and get it close? I would think it would need more jet to go with more air flow




Try them.... see how it acts then start to dial it in...
dont stand on it for long if you do stand on it till
you check the plugs

Re: Holley 4 corner idle questions? [Re: HotRodDave] #534593
11/28/09 02:08 AM
11/28/09 02:08 AM
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Today? Who Knows?
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Jet sizes can be effected by air bleed size as well as venturi design... Along with the sizing of PVCR's...

Re: Holley 4 corner idle questions? [Re: HotRodDave] #534594
11/28/09 09:30 AM
11/28/09 09:30 AM
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""72 and 75 in the street avenger.""

When you run this carb the motor acts better and it is setup much leaner than the 830. Try the 72's in the primary side of the 830 and test it but don't run it hard until you know it is not too lean. If it pings any, then try the 75's in the primary side. If either one work, then try jets in the secondary side 8-10 sizes bigger and then continue testing.
Note: The 86's in the secondary side are large jets, so that is why you don't want to jump on the carb too much becuase the large secondaries might cover up a lean condition on the primary side while you are testing and give you a false test.


1970 YO7 A66 [Canadian Export] F8 Challenger
340 (Currently in shop for stroker assy.)
Re: Holley 4 corner idle questions? [Re: YO7_A66] #534595
11/28/09 01:01 PM
11/28/09 01:01 PM
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HotRodDave Offline OP
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Can I just pull the link between the two sides of the carb and tune the primaries first then add the secondaries back in? It seems to work good for me when I run t-quads

I think if I can not get it runing decent today I might just build one of my core 850 t-quads


I am not causing global warming, I am just trying to hold off a impending Ice Age!



Re: Holley 4 corner idle questions? [Re: HotRodDave] #534596
11/28/09 05:22 PM
11/28/09 05:22 PM
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Yes, pull the linkage and do your cruise tuning to see how it reacts. That would also be a good time to tune the primary squirter too.
Just wait to do the performance tuning until you know what the secondary jets should be.


1970 YO7 A66 [Canadian Export] F8 Challenger
340 (Currently in shop for stroker assy.)
Re: Holley 4 corner idle questions? [Re: YO7_A66] #534597
11/28/09 07:11 PM
11/28/09 07:11 PM
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Kalispell Mt.
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HotRodDave Offline OP
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OK I ran it with the secondaries unhooked, no differance.

Plugs were looking pretty dark with black running most of the way up the electrode, sandblasted them clean and re installed with 74 jets and it felt the same but the plugs were looking better after running a couple miles steady then shutting it down, I think it may be too lean now as the black was barely on the electrode and the plugs were ghost white.


I am not causing global warming, I am just trying to hold off a impending Ice Age!



Re: Holley 4 corner idle questions? [Re: HotRodDave] #534598
11/28/09 07:38 PM
11/28/09 07:38 PM
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ELYRIA,OH
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keepup the good work.if you had to go to the track to tune that it would take forever.

Re: Holley 4 corner idle questions? [Re: HotRodDave] #534599
11/28/09 07:59 PM
11/28/09 07:59 PM
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http://www.empirenet.com/pkelley2/sparkplugreading.html

I think you are moving in the right direction. There should not be allot of dark color on your porcelain. Look at the base ring of the plug for jetting.
EDIT: Two things besides rich jets that will make your plugs look rich are a weak ignition and too large of squirters. You want the smallest squirter/pump cam as long as the engine does not sputter from a light take off.
What cam? Pink?
I would now suggest that you work on the primary squirter to see if that helps. Try one change at a time and try and drive for 20 minutes or so before checking your plugs.

Last edited by YO7_A66; 11/28/09 08:31 PM.
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