Carb selection needed soon.

[170-3tree]

Hey all,

I have been working hard at getting my engine ready for the aluminium head and almost there. I figure I should start deciding on which carb to get. I wish I could afford a six hundred dollar pony carb, but it just isn't going to happen that way. Regardless I do plan on using an Autolite 2100 from another source.
I got into researching, calculating cfm needs, etc. and according to all of this was set on either a 1.14 or 1.21 carb because they are both right around what I need for CFM with the new head. But I stumbled across the "day at pony carbs" page and started second guessing myself.

http://classicinlines.com/PCdyno.aspLink to the page

We all know that he did better with the 1.02 than the larger 1.08 2bbl carb.

My question is probably a matter of opinion until someone puts the effort into scientific testing, BUT!!, Would someone say that this is more factored by the head and intake, or the engine in all entirety? It just goes to prove to me again, that bigger is not always better and throwing random parts at a car probably won't get you anywhere near what you expect.

Thank you all,
Gerald.

P.S. I did search and this is such a bland topic that i got way too many results searching the forum for this answer.

 

[MPGmustang]

IIRC, I made the same HP with a 1.02 as with a holley 350 on my 2-1bbl adaptor on the dyno... the holley 350 said it made more but going through it the 1.02 made more most often and the holley only had 50rprm range of a 'hic-up' that made it peak higher...

the 1.02 made more torque and HP all the time, BECAUSE of the higher velecity through the ventrui,

now with the direct mount 2bbl, IDK what would be better, but I suspect the smaller will get a better off the line response as compared to the larger carb that I'm using right now.

so in short terms, it depends on how fast the velocity is, peak velocity through the carb = max power. but because of max velocity the max CFM is reached faster and the peak top end is a little 'hindered' or 'held back' until u put a larger CFM carb. so for tuning, I suggest sticking with the 1.02 or the 1.08,

side note, IIRC the AF/R for the 1.08 was off and they coudn't jet it.

 

[170-3tree]

I figured it was more in the carb or intake on THIS example, but its still causing me concern, either way, I'm glad that I did this bit of research before getting the larger carb, since it would probably be even worse for me than this example.