More carb questions

[bb71challenger]

Stroker, you put the guard under your carb incase the bottom falls out?  They used to drop parts into the intake. They make a screen for that

Intersting thread but this actually made me lol. Do you mean to tell me that a Dominator will let go and drop parts into the engine? That is just wrong. 

[Chryco Psycho]

there is a bolt for the secondary linkage exposed under the dominator , you run a gasket or spacer to prevent this happening

[Roppa440]

You just need to learn to tune better,, drilling holes in the throttle plates is just a band aid IMO.... accidentally go to big and you cant go back.....

....8, 9, 10...deep breaths. Put your mind in a happy place Roppa....

Right Mr StRoKer. If you look at any normal Holley intended for use on a performance car you will see that they come with holes already drilled in the throttle blades. Even the little six pack carbs have holes pre-drilled in the throttle blades. Why do you think they are there?

And yes. If you go too big you can go back. Obviously if you are an idiot you would just throw the carb away and buy another one.
But why would you drill too big? For every 0.5mm bigger you go you only increase idle speed by around 50rpm or so. Although this changes as you go bigger because the area of the hole increases more. I don't like going bigger than 2mm on any blade. Usually if 1.5mm is not quite big enough I start on the secondary blades.

On carbs without a secondary throttle adjustment you have no other choice.

As for all big cam engines being rich at idle. Well in my experience if you dial in plenty of initial advance, and have the primary throttle blades closed far enough, you can clean the idle quality up quite well. I actually use a wideband O2 sensor to get the idle mixture down to around 14.5:1 to 15:1. This helps to keep the plugs clean and improves idle speed mileage by about 15%.

There was also a comment about getting a big carb to run on a small engine. Well that just shows the amount of ignorance around this subject. Can you imaging how weak the signal strength will be with airflow that weak? So yes it can be done. But it will never work as well as a carb the sight size. Why do you think carbs come in different sizes?

[BB73Challenger]

WOW has this topic become a hot button!

Right off the bat - I do know NOW the rep these carbs have, and even experienced it myself firsthand when something as simple as the fuel needle won't seat because the tang from the float won't match up to it and causes constant flooding. And that's just 1 example I had with my new out of the box carb.

This carb does not have an air bleed -

The cam specs and vacuum it's pulling I will have to check again, the cam specs are in the garage by my car is not, and I would have to put a tester on it again to remember where it is.

[Chryco Psycho]

Roppa is dead on 
 I too have cleaned up idle quality with long duration cams using lots of advance & drilling holes in the throttl plates to keep the p[lates closed & allowing the idle transfer slots to do the work they are meant to do
 It is also very possible to over carb an engine , I tried to tune a 351 Ford engine last year with an 850 DP carb on it , I spent the better part of a day tuning it & made it much better as the owner Really wanted to use that carb , probably 5 hrs into this exercise & installed a 750 to show him the difference between the best I could do with the 850 & the smaller 750 .... the car instantly ran better than at any point with the 850 , we left the 750 on the engine . on the other hand with my 440 / big cam ported factory iron heads & headers I started with an 850 it ran well , I came across a 950 & tried that , it ran faster in the 1/4 & didn`t lose low end response , I then found a 1050 Dominator for $200 & changed intakes & tried that , the car ran .2 second faster in the 1/4 mile  , this will not work with a mildly cammed stock engine but it proves an engine can use a lot of air of the carb is tuned well & responds well to a given combination , the 6 pack is the perfect example along with the TQ using either on a 340 would seem to be crazy with the TQ at 800cfm & the 6 pack even bigger , but both were limited by vacuum draw to open the carbs up & with smaller primary venturis responded well

[71chally416]

You can't beat a TQ for a clean idle and plenty of air when you open it up. The TQ's were made for Chrysler motors and that's why they work so well stock. Ditto with the 6-paks. The only store bought Holleys I ever owned that worked right from the get-go were Pro Systems carbs. The average Joe just doesn't have the wet flow test equipment they have or the thorough understanding of how everything works. Give them your engine combo on the build sheet and they'll send you a carb that works right the first time. That isn't the place to skimp with a budget fit-all universal part if you're serious about performance.