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Target Air Fuel ration N/A engines.?

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Old 11-07-2016, 09:24 PM
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Originally Posted by BenPerfected
We shut the port engine down and idled the last short distance to the dock. Per the engine builders request, we pulled the #3 & #6 plug and sent him a picture of each plug. His comment was they were perfect. Also we have zero soot on the transom. Much of the credit goes to the 1150 CFM Holley Marine Dominators. We quit bothering with the AFR meter as these carbs are spot on out of the box. We now also just touch the key to fire the engines and we can now idle at less that 500 RPM in gear. Docking is easy without stalling and not touching the throttles. Not bad for 500 ci 9.5 to motors making 780 HP. Only took us 20 yrs to find the right high HP combination that works in a pleasure boat.
Good job. I'm jealous. It would take most a lifetime or more including myself. I gotta ask though what rpm at 780 hp.
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Old 11-07-2016, 09:34 PM
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I thought you where using the newer Ultra Dominators Gen 3's ?

Are they the 2 circuit 0-80905HB ?

https://www.holley.com/products/fuel...arts/0-80905HB


Last edited by SB; 11-07-2016 at 09:42 PM.
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Old 11-07-2016, 09:59 PM
  #133  
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Here are the carbs we are using and they were purchased at Jeg's in 2013. These carbs were not officially "Marine USCG" but we did buy and install the Holley J-tubes. I kind of lost the end of the string on some the newer Holley nomenclature and offerings.

Gen 3 Ultra Dominator 4500 Series Carburetor
1150CFM
2-Circuit
1 x 4 Carb Set-Ups
1.830" Venturii
2.00" Throttle Bore
Black

http://www.jegs.com/i/Holley/510/0-80905BK/10002/-1

Last edited by BenPerfected; 11-08-2016 at 05:40 AM.
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Old 11-07-2016, 10:26 PM
  #134  
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Originally Posted by getrdunn
good job. I'm jealous. It would take most a lifetime or more including myself. I gotta ask though what rpm at 780 hp.
6800 rpm, 500 ci w/3.75" stroke. Similar to the APBA Super Cat engines. The bore/stroke ratios are the same as the SBC. The HP is limited by the 9.5 to CR but they run great on premium pump gas.

Last edited by BenPerfected; 11-08-2016 at 05:43 AM.
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Old 11-10-2016, 08:28 AM
  #135  
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Originally Posted by BenPerfected
What do you think about the color of these plugs after a long hard run at 6000+ RPM....sorry about the triple attachment��
Hard to tell from the pic. There should be a heat mark on the grounding strap which I cant see. Would need to see how far back the heat mark is from the tip.
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Old 11-10-2016, 08:32 AM
  #136  
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For me cruise RPM is anywhere between 3300-3800. 3300 is low 50's and 3800 is 62-64mph depending on fuel load.

I don't cruise at 4K+ because I start seeing boost right around there. 3800 is around zero and the boat is running a good number. Above that and into boost (1-3 psi), it starts sucking down fuel and for me it's not worth cruising at 4K+.
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Old 11-11-2016, 02:41 PM
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Originally Posted by Panther
Hard to tell from the pic. There should be a heat mark on the grounding strap which I cant see. Would need to see how far back the heat mark is from the tip.
I've always tried to be just up from the bend. I was looking for as well to see how timing was but looks like new plugs and probably 32 deg of timing or less if I had to guess but is difficult to see from angle of pic.
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Old 11-11-2016, 02:49 PM
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Originally Posted by Panther
For me cruise RPM is anywhere between 3300-3800. 3300 is low 50's and 3800 is 62-64mph depending on fuel load.

I don't cruise at 4K+ because I start seeing boost right around there. 3800 is around zero and the boat is running a good number. Above that and into boost (1-3 psi), it starts sucking down fuel and for me it's not worth cruising at 4K+.
That's pretty good speeds though to stay out of boost. Fuel consumption still prolly not the greatest but who cares as long as there's a port within sight right! When my partner and I had identacle boats we'd run neck and neck. Only difference was he had 525sc's and I did the 454/330 on roids deal and if I had to guess he'd use at least 1/3rd more fuel than I. At least. They sure sound awesome though.
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Old 11-14-2016, 01:43 PM
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Any educated guesses on how to richen up the 3500-4500 zone and lean the wot a smidge on the QF850m? Currently have the stock two port 6.5PVs.
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Old 05-16-2017, 11:02 AM
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Are the Holley and QF power valves interchangable? I don't want the high flow units that QF makes. Or would you all recommend using the 4 door units and leaning the secondary jets down?

Last edited by Baja Rooster; 05-16-2017 at 11:09 AM.
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