2 Circuit Dominator Conversion

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2 Circuit Dominator Conversion

Post  supervel45 on May 11th 2016, 12:41 am


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Re: 2 Circuit Dominator Conversion

Post  rmcomprandy on May 11th 2016, 10:19 am

This is for people who don't know what they are doing and need to take the cheap way out.

Holley and a lot of other places sell separately and new, the correct blocks for 2 circuit Dominators; regular and adjustable billet.

Other blocks will work when modified correctly but, if you don't know what you are doing then going through that hassle is not smart.

EDIT: I accidently erased the original maessage but it is quoted in the next post.


Last edited by rmcomprandy on May 12th 2016, 9:44 am; edited 6 times in total (Reason for editing : Trying to recover a mistake just didn't work.)

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Re: 2 Circuit Dominator Conversion

Post  supervel45 on May 12th 2016, 6:24 am

rmcomprandy wrote:

That is for people who don't really know what they are doing and need to take the easy way out.
Even then, they go through a lot of extra trouble when all you actually need to do is change blocks and air bleeds; IF you want to go the 2 circuit route.

I don't know. If you are going to install removable jets in the metering block to play with tuning it does not seem like such a bad idea, especially if you don't have the correct blocks for the conversion? I have never fooled with Dominators and know very little about them but, I am willing to learn. I am all in for getting the correct blocks for the job if you can though.

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Re: 2 Circuit Dominator Conversion

Post  BigBlockRanger on May 12th 2016, 10:59 am

I did it to my 1050 because I street drive the car. I wanted it to behave like a big 4150.

Motorsportsvillage is pretty much defunct since the owner went beserko and locked everyone out.

The guys from there that really know how to make a carb work are now over at http://racingfuelsystems.myfunforum.org/index.php

LOTS of good info in there.

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Re: 2 Circuit Dominator Conversion

Post  supervel45 on May 12th 2016, 1:36 pm

BigBlockRanger wrote:I did it to my 1050 because I street drive the car.   I wanted it to behave like a big 4150.  

Motorsportsvillage is pretty much defunct since the owner went beserko and locked everyone out.

The guys from there that really know how to make a carb work are now over at http://racingfuelsystems.myfunforum.org/index.php

LOTS of good info in there.


I was searching for something else and stumbled across the page and website and thought it had some interesting tips and pictures and though I'd share. I'll have to check out that website you linked also. The old wire down the air bleeds that Randy likes sometimes is a cool Old School Trick, and I've even seen people put wire inside the metering block and leave a 1/4" pigtail and let the metering block gasket hold it in place. Try different diameter wire until you get it where you want it to be fuel wise. The screw in bleeds up top are much nicer though.

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Re: 2 Circuit Dominator Conversion

Post  BBFTorino on May 12th 2016, 2:24 pm

Converting my 3 circuit Dommy to a 2 circuit setup was the best thing I did to that carb!!

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Re: 2 Circuit Dominator Conversion

Post  rmcomprandy on May 12th 2016, 6:35 pm

Three circuit carbs are just not good at part throttle positions but, wide open throttle is a different story.  Even with a 4150.
So, it depends upon what you want it to do.

I have built many carbs with a 2 circuit primary side and a 3 circuit secondary side.

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Re: 2 Circuit Dominator Conversion

Post  FalconEh on May 12th 2016, 8:23 pm

rmcomprandy wrote:Three circuit carbs are just not good at part throttle positions but, wide open throttle is a different story.  Even with a 4150.
So, it depends upon what you want it to do.

I have built many carbs with a 2 circuit primary side and a 3 circuit secondary side.

Interesting Idea
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Re: 2 Circuit Dominator Conversion

Post  hienergy557 on May 12th 2016, 10:28 pm

rmcomprandy wrote:Three circuit carbs are just not good at part throttle positions but, wide open throttle is a different story.  Even with a 4150.
So, it depends upon what you want it to do.

I have built many carbs with a 2 circuit primary side and a 3 circuit secondary side.

The main jet should be the same in a 2 circuit and a 3 circuit, unless it's up near the #100 range where a Holley 3 circuit block has a restriction in the main well ( idle tube)
So why would you want one that is rich at idle and part throttle and has trouble getting up on the brake.
Best thing I done was convert mine to 2 circuit. It drives nice, doesn't foul plugs and uses half the amount of fuel the 3 circuit did.
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Re: 2 Circuit Dominator Conversion

Post  FalconEh on May 12th 2016, 10:42 pm

I was thinking street/strip Dommi
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Re: 2 Circuit Dominator Conversion

Post  DaveMcLain on May 13th 2016, 8:04 am

f your 3 circuit carburetor runs rich at part throttle it is because the intermediate circuit is NOT calibrated correctly. The reason that the Dominator was developed with a 3rd metering circuit was to allow it to have better part throttle drivability in circle track applications. Without the intermediate circuit the main would have to be slightly over jetted to allow it to start feeding fuel early enough in the throttle opening to not create a metering "hole". If used correctly the intermediate works sort of like a mechanical power valve and it enriches the mixture about 1.5 ratios until the main starts to feed. That's all it does and after the throttle is opened far enough to get fully on the main its influence over the mixture becomes less and less but just like the idle circuit it is really always feeding some fuel.

In modern Dominators with annular boosters the intermediate is probably less important especially in a drag application if power valves are not used because the carburetor is always feeding a power mixture from the main. If the carburetor is built to use a power valve a correctly calibrated intermediate circuit is essential and can give part throttle drivability that will rival the very best 4150.


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