Carb sizing calculator?
 

Is there a good calculator or matrix somewhere available as an online resource that matches up carburetor sizes (bore, jet size, etc.) with engine displacement size (e.g. 2.2, 2.7, 3.0, 3.2, etc. . .)?

I am considering a carb conversion for my 2.7, but it'd be nice if someone has put together a table showing appropriate matchups. If not, maybe I'll start one.

I don't have it handy, but the Weber formula is in Bruce Anderson's original High Performance Handbook...

There are formulas but since the only choices are 40 and 46 for the carbs there is not much need for one. The venturi sizes are also known for each type engine. If you have a race engine up to 3.2, you should use 46mm carbs. If you have a street engine 3.0 or smaller you should use 40mm carbs. Bigger than a 3.2 race engine should probably use PMO 50mm carbs.

-Andy

Thanks for the info, but that's kind of a non-answer. The venturi sizes might be "known" to some, but not to all, certainly not to me. As such, I'd appreciate actual numbers rather than generalized statements about how ignorant I apparently am. Yes, I looked and yes, I searched. Excuse me for asking an honest question. I certainly didn't think it warranted a condescending put-down.

Maybe this will help. This comes from Pat Braden's book on Weber Carburetors.... I'm working on the same issue. I'm carbing a 2.7 in mild configuration, so the chart says about 34mm venturi. Hope this helps!
http://forums.pelicanparts.com/uploa...1202134831.jpg

That's exactly the sort of thing I was looking for. Thanks so much!

Like you, I'm considering a carb conversion to a 2.7, but I need to study up.

Rule-of-thumb Venturi size =20*SQRT(Cylinder Volume in cc's/1000*RPM of peak HP/1000)

(From the Bradon's Weber book)

Sorry you took it as a put down. I just didn't feel like opening up my books right then. I thought you were asking for a formula and I was just saying the numbers are available in books like Bruce Anderson's so you don't need to use a formula.

-Andy

My 2.7 with factory Heat Exchangers and sport muffler was happy with the following:

40IDA3C
34 vents
60 idles
140 mains
F26 emulsion
180 air correction
All the screws were a little different but all around 1.5 turns out.