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Holley 4500 Dominator 1050 CFM

62K views 40 replies 17 participants last post by  BillyGman 
#1 ·
I have this carb installed on my 496 BB and at Idle all I can smell is fuel (running rich) so I was tuning the air/fuel mixture screws and it never cleared up. So whats next, Jetting? Does anyone know what size the jets are that came in the Carb. I am running a Pro billet distributor from MSD along with their 6AL ignition box and blaster coil so I know I am getting enough spark. Please help me this is driving me crazy.
 
#3 ·
Larry,

It depends on which version of the carb you have. HP version? 2 or 3 circuit?

To fix a rich idle you are going to have to restrict (REDUCE) the idle feed restrictor (fuel) in the metering block or INCREASE the air bleed in the main body or both.

If you aren't running a primary power valve, I would highly recommend it if you intend to cruise with the carb.
 
#5 ·
Larry,

It depends on which version of the carb you have. HP version? 2 or 3 circuit?

To fix a rich idle you are going to have to restrict (REDUCE) the idle feed restrictor (fuel) in the metering block or INCREASE the air bleed in the main body or both.

If you aren't running a primary power valve, I would highly recommend it if you intend to cruise with the carb.
I think that Jason is on the right track here^... but in case you don't already know this, Dominators are known for being some of the worst carbs for street cruising, or for any part throttle operation for that matter. They're intended mostly for full throttle operation, and above 3,000 RPM, and that's where they shine.

Some aftermarket companies have come out with their own versions of Dominator carbs which have the circuits extensively re-worked in order to tame the typical Dominator trade mark of being overly rich during any part throttle inputs. AED is one of those companies, offering their "Pro Street" Dominator carb. Good luck with yours.
 
#6 ·
If it is an older 8896 it was jetted 88 square when new.( mine was anyway)

I say older meaning before the HP version, which is 8896-1. Don't know what they have.

Dominators are not intended for a street car. They are for racing so I think getting it to idle clean will take some "know how."
]
Anyhow, I don't know if it is true for a dominator but on a 4150 if the idle mixture screws do nothing when you turn them, that usually means you have the throtle speed screw adjusted in far enough to uncover the transfer slot in the base plate,which causes you to pull fuel from the main circuit rather than the idle circuit.
 
#7 ·
Billy and Todd,

A well tuned dominator can work just fine on the street. Good starting, good idle, good off idle, and obviously at WOT.

They don't just get there by themselves though out of the box ;)
 
#9 ·
Billy and Todd,

A well tuned dominator can work just fine on the street. Good starting, good idle, good off idle, and obviously at WOT.

They don't just get there by themselves though out of the box ;)
Can you point me in the right direction to getting my carb a little more streetability?

Well at least not smelling like Fuel at idle?
 
#15 ·
This^ is a very good point. How high are you reving this 496 engine? And what cam and combustion chamber size is in it? I have a 1050 CFM Dominator carb on my 632 CID engine with a camshaft that has a 268/271 duration @.050 and a power peak of 5,900 RPM. If you're not winding this 496 engine past 7,000 RPM, then you might not need such a big carb. In that case, even if you jet it down, the venturi cross sections might be too big, and might provide a weak signal due to lack of adequate air velocity.
 
#16 ·
My rev limit is 7000. I have AFR 335CC heads, Lunati Voodoo solid roller cam, Brodix single plane intake. Heres the cam specs:
* Advertised Duration (Int/Exh): 285/293
* Duration @ .050 (Int/Exh): 255/263
* Gross Valve Lift (Int/Exh): .680/.680
* LSA/ICL: 110/106
* Valve Lash (Int/Exh): .018/.018
* RPM Range: 3000-7200
* Includes: Cam Only
 
#18 ·
Billy,

My 445 SBC ran a modified 8896 - 1050HP that flows 1100 cfm. I can reach in the window and hit the key and it lights off and will idle at 800 RPM if I choose to. Idle Air/Fuel ratio is ~14-15:1. Thats an SBC with .765" intake lift.

Peak power on my combo is 6600 RPM. ~730 HP.

There is no reason Larry shouldn't make similar power. A 1050 Dominator can be made to work on his combo, it just might take a little patience and work. Would it be easier with an 4150 - 850 cfm carb, probably. That is no reason to just give up and sell a good carb and intake for half price (used) just because it is easier though.
 
#21 ·
OK Jason, thanks for sharing that. Here's a sincere question for you, and it isn't meant to provoke debate. Just a question..... As good as your 445 small block ran with that Dominator carb, do you think that it would've even had an even fatter powerband or run even quicker ET's with a properly tuned 4150 carb, and all else being equal? Just curious what your veiwpoint is on that.

And do you think that the slower air velocity across the wider Dominator venturi creates an extra tuning challenge? I'm thinking that's what you meant in your last post, but I don't want to assume that.
 
#19 ·
Larry,

Raise that rev limiter bud and let that dude eat! (provided the shortblock is built for it).

I wouldn't be surprised if peak power is ~7000 RPM with those heads/cam on a 496. I would definitely raise the limiter to 7800 RPM and try shifting at 7000, 7200, 7400, 7500 and see what happens at the strip.

How much compression?

What rear gear?

What size headers/exhaust?

How much timing are you running? Timing at idle? How quick does it come in? If compression is pretty low, I would lock the timing out starting at 36 degrees.
 
#26 ·
Larry,

Raise that rev limiter bud and let that dude eat! (provided the shortblock is built for it).

I wouldn't be surprised if peak power is ~7000 RPM with those heads/cam on a 496. I would definitely raise the limiter to 7800 RPM and try shifting at 7000, 7200, 7400, 7500 and see what happens at the strip.

How much compression?

What rear gear?

What size headers/exhaust?

How much timing are you running? Timing at idle? How quick does it come in? If compression is pretty low, I would lock the timing out starting at 36 degrees.
My Compression is somewhere between 12.3 - 12.5:1 and I have not gotten to the rearend just yet. But I am building a 12 bolt with either 4.10 or 4.56 gears haven't decided just yet but I'm leaning towards 4.56 cuz of the 6 speed manual tranny. I am running Hooker comp headers 2" primaries to 3.5" collector with a 3.5" exhaust (pypes X pipe and dynomax race bullets to turn downs right before the rear axle). Timing at idle is right around 21 and total comes in around 3000 for a total of 38 degrees.
 
#20 ·
Thats right on the money,now that we have some engine specs,this motor should pull enough air to run the 4500.Is the carb new?Or did you get it used,off sombodys shelf.These are senitive carbs,what with air bleeds,adjustable secondaries,ect.Ive seen plenty of screwed up carbs that were done by "tuners".We are not going to fix it here,if you have a good dyno shop in your area,talk to them,if they cant fix it,theyll know sombody who can.Mark.:cool:
 
#24 ·
I'll try to help out guys. I have a Prosystems HP1000 on my 496, 10.5:1 with AFR 315. I have to change out high speed air bleeds to hopefully get rid of a lean pop around 7000. One of several things Patrick suggested--great service BTW. Seams like I have been lean on this motor at higher RPM's. I have 92/99 jets in now. Runs and idles fine and deadly consistent just top end pop. Taking additional jets and plugs next week to TNT. Also, a friend has a similar weight, motor size and power (although a Ford) but he's going to let me try his 1050 dominator (custom builder but forget who). I will not switch it over until I quit tuning on the current 4150 HP1000 then run it right after and see some real work results. BTW, with the new gear and convertor this year, i have been going through around 74-7500. During burnout, accidently hit 7900--no bog there though:). Do not be afraid to spin that motor if it likes it.
 
#28 ·
Larry, I'm sorry to say that 8896 has crappy out of the box metering, however getting it to idle should not be hard. First thing I would do is start running the timing up to see if you can get a better idle quality. A cam that big will usually like a lot of initial timing and in some cases locked out. If you find it runs better you will need to limit the mechanical advance to keep your max timing to 38 if that is where it runs best. After you get the timing fixed and readjust idle speed and mixture, pull the carb and make sure the transition slots have only about .020 exposed. Once you get the idle straight be ready for more fixes. WHEN, not if, you see that it seems rich in the midrange but not at WOT you will have to work on the intermediate circuit. But thats another conversation and another day....
 
#30 ·
DRAGRACER wrote:"There is no reason Larry shouldn't make similar power. A 1050 Dominator can be made to work on his combo, it just might take a little patience and work. Would it be easier with an 4150 - 850 cfm carb, probably. That is no reason to just give up and sell a good carb and intake for half price (used) just because it is easier though."
*********************************************

I agree with Jason on this one. I have my Dominator on a BB 427 with a tiny 224/.050 hyd flat tappet cam. I put it on there while the 540 is out because I didn't want to buy another manifold and carb. After spending several hours tuning it, thanks to info here and on the Innovate "tuner" forum, I have a Dominator that drives like a 2bbl. It started out as a 3 circuit, but is now a 2 circuit with power valve, and adjustable IAB's, etc.

Like Jason said, it can be done, but it does take some time, and might get more involved than some guys would like. It's not magic, and I learned A LOT while doing it. Mine idles at 13-1, WOT is about 12.5-12.8 and cruise is 16-17/1 in the 3000rpm range. Original test it was idling at 11-1 and crusing at 10-1.

As for my 427 needing a carb that big...no doubt it would do fine with 750, but it does fine with the Dominator, and they can be tuned to be tame for the street while still delivering max power at WOT when you need it, ie, at every stoplight!!

The advice you have gotten here so far is better than I could give. Start from the baseline and change ONE THING at a time. You'll get there.

Bob
ps. I mentioned the Innovate website; it is down for an overhaul right now, but there is a "library" of tuning info there if you want to learn once it's back online. All kinds of Dominator threads.
 
#31 ·
Thanks Bob, I'll definitly have to check it out when it comes back online. My biggest problem is the unburnt fuel smell when at idle. When the motor is cold i can pump the carb twice and she fires right up.
 
#32 ·
I got the pop out of my 4150 with .026 air bleeds and 87/93 jets. A little more normal on jetting than before. It still ran about the same. Then 3 weeks ago tried and out of the box 1050 dominator. It would idle fine but around 1-3000 cut out but I did not really care since I was just trying out for the quarter. First pass slowed .08 then another .10 on the second pass, then another .10 after that. I think I fouled the plugs. I did not change any jetting since the carb is about 5 years old. I did not want to mess up the fuel bowl gaskets at the track since I did not bring any spares. I figured I was close enough with my Pro-Systems 4150 that I did not need to spend another $1000 for a dominator. The good news is though, after tinkering with my 4150 is that I beat my best 1/8 mph by 4 mph. Old 109 and new is 113 mph and that was on foot brake vs. trans brake. Finally got some nice weather, high 70's and 40% humidity.
 
#36 ·
Its all in the metering of the carb. Google the 8896 and you will find answers. Most Holley carbs are not good out of the box.
 
#37 ·
I need help bad,i bought a new 1050 dom 8082-1 2 circuit,put it on motor runs lean as hell no matter how you adjust it,no vacuum leaks, and I put in new plugs its a 427 030 13 to 1 comp,600/620 lift cam, canfield heads, you mean to tell me you buy a new carb and you have to work on it out of the box.If you have been through this can you help me? I am new at this can you send response to my email troxaat@gmail.com thanks Alfred.
 
#41 ·
..... you mean to tell me you buy a new carb and you have to work on it out of the box.
Al, aftermarket carbs are generic. They aren't for any specific engine vehicle combination. Therefore, there's going to be tuning involved for the end user. That's what removable main jets, power valves, fuel squirters, throttle linkage cams, and adjustable air bleeds are all for. These carbs don't come in the box set up and adjusted perfectly for your specific engine combination. That would be impossible. If that's what you want, then you should give places like AED Performance a call. AED Performance | Racing Carburetors | Holley Carburetors They'll require all your engine/vehicle specs before they build your carb for you, (ie. engine size, cylinder head port volume, static comp ratio, engine redline RPM, HP, TQ, rear gear ratio, rear tire height, camshaft specs, stall speed RPM, and vehicle weight).
 
#38 ·
You mean lean at idle...cruise or WOT? That's a pretty good basic carb to start with for a street version. We used one a buddy's 427 BBC and it did OK.

JIM
 
#40 ·
Old thread new question.
 
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