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Converting a 3 circuit dominator 4500 to 2 circuit.

PostPosted: Tue Jul 05, 2022 5:11 pm
by bigblockmark
What is the next best way to convert a 4500 1050-1250 gas Holley Dominator carburetor from 3 circuit to 2 circuit? I know the metering blocks can be changed to do it, but is there a way of still using the original 3 circuit metering blocks? Can the intermediate curcuit be blocked some way? How? Is it as good as replacing metering blocks to do it? Pictures.

Re: Converting a 3 circuit dominator 4500 to 2 circuit.

PostPosted: Wed Jul 06, 2022 2:29 pm
by rgalajda
Are these the ones with the idle tube in the main well and the intermediate circuit in the main venturi ?

Re: Converting a 3 circuit dominator 4500 to 2 circuit.

PostPosted: Wed Jul 06, 2022 5:59 pm
by bigblockmark
I was asking in general. No specific metering blocks, just stock Holley for 8896, 9375, 80532 ETC. They have the solid plugs on top, not cups. Cover all options if you want to.

Re: Converting a 3 circuit dominator 4500 to 2 circuit.

PostPosted: Thu Jul 14, 2022 2:49 pm
by bigblockmark
Bump for more input.

Re: Converting a 3 circuit dominator 4500 to 2 circuit.

PostPosted: Sat Aug 13, 2022 3:18 am
by jmarkaudio
You can do it with the stock 3 circuit blocks but will be limited to the amount of HP worth of fuel you can get thru them without modifying them. Larger mainwells, angle channels. The other issue is how the idle feed works, and where the restriction has to be located. The original blocks had the bottom of the tubes pinched, better, but no way to change the restriction size.

Re: Converting a 3 circuit dominator 4500 to 2 circuit.

PostPosted: Sat Aug 13, 2022 2:02 pm
by bigblockmark
I have heard of racers simply removing the intermediate air bleeds and just leaning out the circuit. Is this reasonable?

Re: Converting a 3 circuit dominator 4500 to 2 circuit.

PostPosted: Wed Aug 24, 2022 12:38 am
by jmarkaudio
Sure, but depending on how much HP the engine makes will depend on what you can get away with. Anything at or over 900 HP you have to be careful how much intermediate fuel you remove with stock blocks as you will at some point run out of passage to get enough fuel thru. Oxygenated fuels make it worse.