We are currently running on the new domain and server: www.Speed-Talk.com

IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/
(Right-click the URL and select "Bookmark this link")

750 holley dominator

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Little Mouse
Expert
Expert
Posts: 506
Joined: Mon Oct 21, 2013 8:48 pm
Location:

750 holley dominator

Post by Little Mouse » Thu Feb 06, 2020 10:50 am

So carb masters how do they make the still 2 inch dia. Throttle blades work down at the bottom with the smaller venturie. I noticed the smaller versions of the king demon RS that they no longer sell they used a bit smaller 1.80 throttle blades, holley dominators have 2.00 throttle blades from the 750 to the 1150 size and 2.14 on the really big ones. I'd like to run a dominator on the street with a to small sbc. Don't see how with 2 inch throttle blades even with a small venturie could work well. If I could find a good used king demon RS with the smaller throttle blades, king demons are supposed to be 3 circuit another supposed to not do thing on a street engine.

pdq67
Guru
Guru
Posts: 8924
Joined: Thu Mar 04, 2010 8:05 pm
Location:

Re: 750 holley dominator

Post by pdq67 » Thu Feb 06, 2020 11:26 am

As, "Honest Charley", said years ago, "The 3310 carb. is the runninest carb. made!"..

I don't think you can go wrong with a newer 3310-2 or even a correct Q-Jet!

But neither one will have that, "LOOK!!"...

pdq67

PRH
Expert
Expert
Posts: 776
Joined: Fri Sep 08, 2017 4:16 pm
Location: S. Burlington, Vt.

Re: 750 holley dominator

Post by PRH » Thu Feb 06, 2020 11:40 am

I’ve only messed with one of those carbs.
The one I had here was dimensionally the same as a 1050, but it had skirted annular boosters instead of the normal ones used in a 1050.
When it was brought to me someone had already trimmed away most of the flange at the bottom of the booster....... and not very uniformly either.

I swapped out the boosters for some normal annular pieces and resized the main wells & angle channels in the metering blocks.

Then it was pretty much just an annular booster 2 circuit 1050.
Somewhat handy with a die grinder.

Little Mouse
Expert
Expert
Posts: 506
Joined: Mon Oct 21, 2013 8:48 pm
Location:

Re: 750 holley dominator

Post by Little Mouse » Thu Feb 06, 2020 4:32 pm

What are skirted annular boosters in the 750 supposed to do for the carb, never had anything but either strait or down leg boosters in holleys. Had several 3310 vacuum carbs had no real problems with them, not exactly a real adjustable holley but then all of the early 4150/4160 carbs were like that. Never did anything but rebuild Q-jets back to there stock setups on pickups lol.

Walter R. Malik
Guru
Guru
Posts: 4680
Joined: Tue Jul 24, 2012 11:15 am
Location: Roseville, Michigan (just north of Detroit)
Contact:

Re: 750 holley dominator

Post by Walter R. Malik » Thu Feb 06, 2020 5:37 pm

Closing down the venturi cross-section will flow less air. So, will making the throttle bore smaller.
There are lots of different ways to get where they want to be.
http://www.rmcompetition.com
Specialty engine building at its finest.

shoedoos
Expert
Expert
Posts: 561
Joined: Wed Aug 09, 2006 3:14 am
Location: New Zealand

Re: 750 holley dominator

Post by shoedoos » Thu Feb 06, 2020 5:41 pm

^^^^^^^^ and? Those different ways are?

PRH
Expert
Expert
Posts: 776
Joined: Fri Sep 08, 2017 4:16 pm
Location: S. Burlington, Vt.

Re: 750 holley dominator

Post by PRH » Thu Feb 06, 2020 5:47 pm

It’s been many years since I worked on that 750/4500 carb, but my recollection is that the boosters for those carbs had a flange at the bottom even bigger than the ones in the pic.

They would have been a very big impediment to the flow.
798C4D05-6F8F-48DD-80D9-150291BEA0E0.png
Actually....... it looks like those are probably the 750/4500 boosters.
67C3790F-5BA3-4478-BA8A-701FB2561588.png
You do not have the required permissions to view the files attached to this post.
Last edited by PRH on Thu Feb 06, 2020 5:52 pm, edited 2 times in total.
Somewhat handy with a die grinder.

turbo camino
Pro
Pro
Posts: 208
Joined: Sun Aug 10, 2008 11:51 am
Location:

Re: 750 holley dominator

Post by turbo camino » Thu Feb 06, 2020 5:47 pm

Considering a 1050 works just fine on a very mild ~400hp hydraulic-cammed SBC, I've always had a hard time figuring out what the 'proper' application is for the 750 Dominators. Maybe if you just had to have dual Dominators on the stock Goodwrench crate motor in your show car?
DON'T PANIC

steve316
Expert
Expert
Posts: 605
Joined: Fri Apr 13, 2007 10:06 pm
Location: St.Joseph,mo.

Re: 750 holley dominator

Post by steve316 » Thu Feb 06, 2020 8:44 pm

Also if you want to change it to a 1050; all you have to change is the boosters. Something to think about.

Little Mouse
Expert
Expert
Posts: 506
Joined: Mon Oct 21, 2013 8:48 pm
Location:

Re: 750 holley dominator

Post by Little Mouse » Thu Feb 06, 2020 9:52 pm

The king demon rs from what I'm reading had changable venturie sleeves 1.80 butterfly on the 795 or 895 sleeve. Then 2.00 butterfly for 995, 1095, 1295 sleeves and all were 3 circuit. The 750 dominator has the same 2.00 butterfly as all the dominator's up to the 1150 size but the 750 has I think it's a 1.62 venturi size. Ya that big bell shaped bottom annular booster would certainly hurt the airflow. As far as buying a new carb you can buy a sportsman 1050 dominator cheaper then you can buy the 750 dominator or I will call it only the look of a dominator not the real thing. I do know this from just my hot rodder type old age exprience putting a really big oversized carb on a dual plane you can get away with it on a single plane harder to do. Now I have never built an engine other then for my pickup truck that was not cammed to do anything less then 7600 rpm or higher I'm not a low rpm person and in a street driven engine you do not have to use all the rpm all the time your choice when to use it.

User avatar
jmarkaudio
Vendor
Posts: 4162
Joined: Wed Sep 26, 2007 11:26 am
Location: Florida
Contact:

Re: 750 holley dominator

Post by jmarkaudio » Fri Feb 07, 2020 11:06 am

The Holley 750 and 1050 carbs share the same body, both with a 1.6875" venturi and 2" throttle bore. The difference is in the skirted banjos, and calibration. An 1150 has a 1.82" venturi and 2" throttle bore. The 1250 has a 1.88" venturi and 2.125" throttle bore. As a side note Holley has what they call a Gen 3 1050, it's actually an 1150 body with skirted banjos... A full skirt is around 1.140", skirts can be cut to any size down to about .925". A straight annular banjo is .900" OD.
Mark Whitener
http://racingfuelsystems.myfunforum.org
____

Good work isn't cheap and cheap work can't be good.

Little Mouse
Expert
Expert
Posts: 506
Joined: Mon Oct 21, 2013 8:48 pm
Location:

Re: 750 holley dominator

Post by Little Mouse » Fri Feb 07, 2020 12:20 pm

jmarkaudio wrote:
Fri Feb 07, 2020 11:06 am
The Holley 750 and 1050 carbs share the same body, both with a 1.6875" venturi and 2" throttle bore. The difference is in the skirted banjos, and calibration. An 1150 has a 1.82" venturi and 2" throttle bore. The 1250 has a 1.88" venturi and 2.125" throttle bore. As a side note Holley has what they call a Gen 3 1050, it's actually an 1150 body with skirted banjos... A full skirt is around 1.140", skirts can be cut to any size down to about .925". A straight annular banjo is .900" OD.
Thanks for all that info. I noticed the sportsman 1050 it said it had the new gen 3 body. I think if I'm going to try this I'll buy the 1050 sportsman. Even with a big cam I'm betting the very least I will have to do is make the idle feed smaller and the idle air bleeds larger. If it has no power valve in the primary I'll put one in it and reduce the primary main jetting.

Little Mouse
Expert
Expert
Posts: 506
Joined: Mon Oct 21, 2013 8:48 pm
Location:

Re: 750 holley dominator

Post by Little Mouse » Fri Feb 07, 2020 2:30 pm

Carb probably has a power valve already in it.

User avatar
jmarkaudio
Vendor
Posts: 4162
Joined: Wed Sep 26, 2007 11:26 am
Location: Florida
Contact:

Re: 750 holley dominator

Post by jmarkaudio » Sat Feb 08, 2020 9:27 am

Get the 950, calibration is a little better and it has small skirts.
Mark Whitener
http://racingfuelsystems.myfunforum.org
____

Good work isn't cheap and cheap work can't be good.

Little Mouse
Expert
Expert
Posts: 506
Joined: Mon Oct 21, 2013 8:48 pm
Location:

Re: 750 holley dominator

Post by Little Mouse » Sat Feb 08, 2020 11:45 am

It's a 4150. If I use the 1050 it will not have good throttle response no matter what I do like smaller carbs would and those 2.00 throttle blades changing position quickly will be a problem and of course the real truth the engine will never pull enough air to really use the carb even at highest rpm. The king demon with the 1.8 throttle blades may be some help that's barely any different then the holley 850 1.75. The 3 circuit may cause me extra grieve. For just a high rpm small 337 what I think should really use is one of the new very adjustible 850s. I do happen to have two of the old 4980, 800cfm carbs laying around have had them for so many years I cant even remember how I came by them and I never used one of them.
Last edited by Little Mouse on Sat Feb 08, 2020 12:24 pm, edited 2 times in total.

Post Reply