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Carb opinions 540's 700 hp...

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Carb opinions 540's 700 hp...

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Old 03-19-2015, 05:25 AM
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Originally Posted by Full Force View Post
define plenty, almost every person has told me more power with dominators.... I look at it this way too, if I must BUY new ones, would it not be smart to buy carbs that will also support future?

I only have HP500 800's now, that wont be nearly enough..
4150 upto 850hp no problem. If it's under 800hp I wouldn't even bother with a Dominator run a 4150. I sold an OSO friend my old Baker Outlaw Carb (4150) for his 540. Dyno'd @ 750hp 6300rpm. sister engine with a Dominator made the same power. some of the World of Outlaw guys are making 900 on a finely tuned 4150.

I would call Steve @Baker Outlaw Fuel Systems. and tell him what you have as far as carbs now. He has a CNC and does work to the main bodies.
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Old 03-19-2015, 06:30 AM
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Originally Posted by Full Force View Post
Thats an E-85 carb. But, they do make a 4150 gas 1050 carb thats very nice.

I've worked on some "custom" carbs built for the customers applications. What I've found with those kind of carbs, is while they ran 'ok' , once the wideband was hooked up, it was easy to see how far out in left field they actually were. Air fuel ratios dipping into the 10's at 75% throttle, cruise speeds so lean the pistons are starting to glow, etc. So, now its time to tune them right in the boat. Oh, wait, look here, they drilled the PCVRs out to .097, so when the power valve opens, its like a flood of fuel being shot into the engine. So you tune your primary jet for a nice efficient cruise. Then, at PV opening, the AFR shoots pig rich. Ok, well, without drilling and tapping the orifices to install a smaller pcvr jet, its easier to shrink down secondary jet, to get an acceptable WOT AFR. Looks great on the wideband, but problem now is, you have a chit ton of fuel coming from the primary circuit, and not much from the secondary circuit. Oh, now the rear cylinders are lean, and fronts are pig rich.

Tune the idle circuit time? Sweet, its got screw in air bleeds right? Oh wait, look here, they drilled out the idle feed restrictors. PFFT. Now, your getting a ton of fuel at idle. No biggie, just turn the mixture screws in to lean it out a bit right? DOH, now you do that, and the engine falls on its face when you shift it into gear because its starving for air too, since you cut that off by turning the mixture screws in. Ok, well, let me open the throttle plates up more. Oh, now it idles at 1200RPM in nuetral so it doesnt stall out.

With a billet metering block like a QFT, all that stuff is easily changeable, and you can easily tailor the carb to the engine, not just at wide open throttle, but from idle to wot.
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Old 03-19-2015, 06:44 AM
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Just because a "custom" carb builder fouled up a carb doesn't mean there is no virtue in having an application specific carb done properly.

Also, while the base offerings have come along way, that doesn't mean you can just toss on a "shelf" carb and everything is going to fall right in line.

Tuning whatever carb you end up with to your application is a reality you won't circumvent.
Id rather have a relationship with a local carburetor expert than be calling a summit racing tech line or asking online when you need help.

I wouldn't paint all boutique carburetor builders with the same brush either. Some guys build more than just WOT bracket racing stuff.
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Old 03-19-2015, 06:50 AM
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Originally Posted by vintage chromoly View Post
Just because a "custom" carb builder fouled up a carb doesn't mean there is no virtue in having an application specific carb done properly.

Also, while the base offerings have come along way, that doesn't mean you can just toss on a "shelf" carb and everything is going to fall right in line.

Tuning whatever carb you end up with to your application is a reality you won't circumvent.
Id rather have a relationship with a local carburetor expert than be calling a summit racing tech line or asking online when you need help.

I wouldn't paint all boutique carburetor builders with the same brush either. Some guys build more than just WOT bracket racing stuff.
I've tuned many carbs in boats both NA and blown with and without widebands. Dean nickerson was supposed to be the guy for custom marine carbs. On the water with a wideband. Waaay off....on several occasions.

There are entirely too many variables for a guy to set a carb up to have an efi like fuel curve , on a bench. Every single boat is different. Nothing worse then spending a bunch of money for "custom" carbs, and having to go retune them anyway. Most of these guys would have been better with an off the shelf carb that allows fine tuning

I don't know dale at cfm. Have you tuned any of his carbs on the water using a wideband ?

Last edited by MILD THUNDER; 03-19-2015 at 06:57 AM.
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Old 03-19-2015, 07:44 AM
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Originally Posted by MILD THUNDER View Post
I've tuned many carbs in boats both NA and blown with and without widebands. Dean nickerson was supposed to be the guy for custom marine carbs. On the water with a wideband. Waaay off....on several occasions.

There are entirely too many variables for a guy to set a carb up to have an efi like fuel curve , on a bench. Every single boat is different. Nothing worse then spending a bunch of money for "custom" carbs, and having to go retune them anyway. Most of these guys would have been better with an off the shelf carb that allows fine tuning

I don't know dale at cfm. Have you tuned any of his carbs on the water using a wideband ?
Not yet.
He set it up with a base setup from the info I provided.
It will be furthur tuned on the dyno and then final tuned in the water with a wide band. (Having O2 bungs welded in the exhaust for a permanent A/F gauge)
This is the second carb I've had done there. the first was little 600 for my small block 306 I had in a little puddle jumper and I didn't have a wide band on the boat nor did I dyno the engine. That said, it was pretty close and only required some fine tuning once in the boat.

I'm not expecting to put the carb on and not have to fine tune it on the water, but I wouldn't expect to be able to just bolt on any carb and be done.

All I was really trying to say is that for a guy like me that knows enough to be dangerous, it's nice to have a relationship with a well respected, local to me, guy that I can dial up and speak to whenever I have a question. Let's face it, and to your point of seeing so many fouled up carbs by "experts", most of us know enough to be dangerous. Any carb in the wrong hands can be goofed up no matter if it starts as a shelf carb or a custom setup.

Last edited by vintage chromoly; 03-19-2015 at 08:04 AM.
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Old 03-19-2015, 08:14 AM
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Originally Posted by Full Force View Post
I am doing 540's afr 325 cc heads bob m cams nearly every person said to see 700 hp I need Dominators and that is my plan but what might be easier option if height is issue? I cannot go higher then my 4150's are now...

Just wanted to see combos and if using Dominators what kinda jetting to start with ...
My advice would be to learn every thing you can about how to tune a Holley and do it your self. Trust me I have traveled down this road ! I have a custom carb from a well known carb guy the last time I sent it back to get FIXED it came back with a new set of $400.00 gaskets!
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Old 03-19-2015, 08:17 AM
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Originally Posted by MILD THUNDER View Post
snip....
With a billet metering block like a QFT, all that stuff is easily changeable, and you can easily tailor the carb to the engine, not just at wide open throttle, but from idle to wot.
Joe, you make an excellent EFI salesman!
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Old 03-19-2015, 08:19 AM
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I know Dale is a go to guy for cars not sure about boats, none of my past engines needed crazy tuning or a big carb, my 600's ran sweet with hp500 carbs with doing wot runs **** off then pull plugs... But in this case I wanna make sure I don't starve engines for air or fuel, I can run my 800's to get by if needed I built engines around using dominator or equivalent ... I don't wanna spend lots of money and be close to max, rather have room for later ...

Guys say 900 is enough, others say 1050+ very respected people told me Dominators.... It's not really the carb being issue I wanna know if I am keeping my intakes or not...
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Old 03-19-2015, 08:33 AM
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Also, there really is no "jetting " baseline for a dominator that is unknown and not purchased yet.

Let's say you buy a pair of stock Holley's used. I'd look up the list numbers in the master catalog and put the carb to stock, and go from there. If its a modified holley, that's been drilled like a cheerleader on prom night, good luck with that trying to get a baseline for it!
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Old 03-19-2015, 08:34 AM
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If you have the room run a dominator. You also can get a 1050 in a 4150.

Last edited by fbc25el; 03-19-2015 at 08:37 AM. Reason: added stuf
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