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 Holley 9380 running on the Ford V-6 
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Joined: Mon Jul 04, 2016 11:37 pm
Posts: 48
https://m.youtube.com/watch?v=KMxRSd8bG8E I got the 9380 Holley running on the V-6,I had one run on it last weekend but I didn't know that I had a 82 jet in the front primary and my racpac O2 did not record O2 but I think it was really rich.But this is how it sounds at home.


Tue Mar 14, 2017 7:32 pm
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Joined: Thu May 08, 2014 7:47 pm
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sounds healthy!


Thu Mar 16, 2017 5:27 pm
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Joined: Fri Feb 08, 2013 2:37 pm
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1972HO wrote:
https://m.youtube.com/watch?v=KMxRSd8bG8E I got the 9380 Holley running on the V-6,I had one run on it last weekend but I didn't know that I had a 82 jet in the front primary and my racpac O2 did not record O2 but I think it was really rich.But this is how it sounds at home.

That 82 jet is too rich with the annular boosters. You can hear it get just a little blubbery as you gradually opened the throttle, I think because it is too rich. It is a snappy thing, isn't it. Light crankshaft. I have been down as small as 74 PMJ to get clean part-throttle with those, but the PVCR must be correct for WOT.

For road racing and circle track, you might try jet extensions in the secondary. This can help prevent over-fueling when you are hard on the brakes. If you get the speed low enough to pull near 1g coming off a corner it can suck air with a secondary PV, so perhaps plug that. Data logging A/F will show you these things.


Fri Mar 17, 2017 10:53 am
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Joined: Mon Jul 04, 2016 11:37 pm
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Tuner" I have this motor in my 72 mustang drag race car,and it has jet extensions.So what would the right pace be with a 74 jet,I've been trying to get a O2 on the thing on the jack stands with the engine turning up to 5000 rpm in gear and it appears lean 14 plus until it the power valve opens then it goes rich to 11 O2 then climbs back to 14 O2 now this is with no load just on the jack stands and that is with a 78 jet in the front and 87 in the rear.


Fri Mar 17, 2017 2:30 pm
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It sounds like you have open headers? You can't trust the O2 when the sensor is near the open end of the exhaust system. At WOT going down the track it is more accurate, but take it with a gain of salt. With a short exhaust system and no load, and particularly with a radical cam engine like yours, O2 is not to be taken as gospel. The fresh air getting back up the pipe will make it read leaner than it actually is. A rich misfire will cause a lean reading because of the unburned Oxygen.

The 78 jet is OK, try it on the track. I didn't mean you should use a 74, I am saying I have used a jet that small in an annular booster 850 carb, in fact also in the "1000 HP" body casting.

The non-HP casting with the choke horn, even if the horn is cut off down to the gasket ring, the primary side acts like a smaller venturi than the secondary, and so will use smaller metering area than the secondary. This is because the vertical wall of the choke horn encroaches on the venturi minor diameter at the left and right sides. This isn't a bad thing, it is just how it is.


Fri Mar 17, 2017 6:33 pm
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Joined: Thu May 08, 2014 7:47 pm
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i agree. only time you are going to have accurate o2 readings is under load on the throttle. The idle circuits sounds like they are pretty close, and you are a little rich when it comes up on the booster. why did you decide to run a power valve and not a block off?


Fri Mar 17, 2017 8:13 pm
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Joined: Mon Jul 04, 2016 11:37 pm
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Jetfast" I had a similar carb on this engine some years back but it was converted to a down leg booster and on the dyno it was running really lean up in the 14 and high 13 on the O2 and that carburetor had block off in pv and it made best power with 88 to 89 squared.Now that was a carburetor that was modified by the carbshop and they told me that with the annular booster that it would run rich,So now i have another 9380 so decided to try and run this carburetor with a front power valve and see how it works I know at one point last week at the track it seemed like it loaded up on the twostep on the starting line.I might just pull the power valve after the next trip to the track,I thought I had the 78 in the primary's but it had 82's and I only got 3 runs that day so next month is a TNT day at Fontana so I may be able to make some changes at the track.


Fri Mar 17, 2017 9:21 pm
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Joined: Mon Jul 04, 2016 11:37 pm
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Well I'm at the Strip in Las Vegas running the 9380 and so far it is running really rich from the hit on the two step first pass O2 was in 10.0 to 10.6 with 88 jetting and no power valve second pass I leaned it down to 84 squared O2 now at about 11.12 first pass et was a 11.64 114.04 second pass 11.47 115.72 and this was with worst air over 1000ft worst.So tomorrow im going to run QF SSR-780-VS with 80 jetting squared and see how that works out.


Fri Apr 21, 2017 10:28 pm
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I would leave the annular carb on it and drop the jet to 81.


Sat Apr 22, 2017 2:51 am
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Joined: Mon Jul 04, 2016 11:37 pm
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8 jet sizes from normal is that something that's done the conditions are not that bad I normally don't even change the netting from Cali tuning to run here.Plus we only will get 2 more passes and I need to see if this QF carb is going to net anything.


Sat Apr 22, 2017 9:35 am
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