Carb advice II

[Zandoz]

I don't want to derail the other thread, so I started this thread.

My issue is with the Holley 390 cfm carbs...namely the price and driveability. I have a little GM 2.8 V6 and an Edelbrock Torker II manifold with a 4bbl top for it. The Holley 390 is the recommended carb for it.

From the very beginning I've been suspect of that recommendation. Every cfm calculator I've tried comes up somewhere in the 250-270 cfm range. Additionally, over on the bay I regularly see used 4bbl tops for the manifold...and I've yet to see a 2bbl top. That leads me to think folks are having problems with the 390s. Then over on the original Carb advice thread, Dave wrote:

....The 390's are positivley "piggy" compared to he 450's... don't waste the money......
dave

The other half of my reluctance to go with a Holley 390 is that they are absurdly expensive compared to what I see with other 4bbl carbs...new, rebuilt, core, or carcase.

I've not found any other small 4bbl alternatives, and I keep getting gas mileage horror stories about going with the Holley 350 2bbl. The only other 2bbl I've found with TV cable linkage available for my 700R4 is the old Rochester 2Gs

At this point I'm between biting the bullet and going with a Holley 390, going rogue with a 2G, or pretending the problem doesn't exist, and maybe it will go away by the time to put the engine together (the philosophy I've been following the last few months).

 

[Mike]

I always question people on how one, particular carb can be any less fuel efficient than another carb.

At X RPM, an engine can only pump Y cubic feet of air. And Y cubic feet of air can only carry Z pounds of fuel.

It's as if we somehow give carburetors some form of artificial intelligence, which allows them to know what kind of engine they are being bolted to, and subsequently allows then to vary their metering accordingly. Or maybe we have intelligent engines, that know what carburetor is bolted to it, which allows the engines to vary their bore and stroke to pump larger quantities of air?

You can safely put the 350 2 bbl myth to rest. Seriously, read the very first word of the Colin Chapman quote in your signature file. It's as if you appreciate the Chapman's wisdom, yet you somehow choose to ignore it. Don't go making things harder than they have to be.

 

[RPM]

But @Mike ,I took my 650 double pumper and put bigger jets in it, so now it is like and 850. Bet you never heard that before. LOL

 

[Mike]

Heh, you've spent your own time in the trenches, you know I've heard them all. One of my personal, all-time favorites were the customers (<--- yes, that is plural, as in it happened a lot more than just once) who would want to drop off a cylinder block, to get it balanced.