I have a 250 with a 194 head, bored .060 over with a mild cam. I am running to Webers right now. They are 24/24mm throats. The car runs pretty good with them but with all the work done to the motor, it seems to me that I should be able to roast the tires. Will the 48 IDAs give me the power I am looking for or am I reaching for something not obtainable with this inline six? Should I go with something like small base Rochesters? Any suggestions would be great. Here is a pic of my intake. Its so unique I don't want to change it. Thats why I am thinking the bigger Webers.
Properly tuned IDAs on a well designed intake will run great. They're pretty spendy though. You may also want to concider some IDFs. Nearly the same porential, much cheaper. Another(and possibly better) option would be the side draft DCOE Webers. side draft would give you a straighter shot into the head for a more efficient intake.
IDFs would be better for a driver...IDAs, from what I remember dont progress very well from idle ..more of a full throttle carb
Without a better breathing intake a pair of 48s won't do much but use more fuel, and kill some of the bottom-end torque you have now. Your intake is truly unique, but how good it is for power production is the question. Of course the hot set-up for a Chevy six is a trio of 45DCOE sidedrafts, but to take advantage of them some pretty decent head work and a cam to match would be in order.
Those 48's flow about 211cfm per barrell, so 2 of them would be about 840cfm and change, I think that may be a bit much for your straight 6...
i think the "new" webers have the third progression hole and mods from the factory to help with transition. not sure though. i had a set on my vw but spent a ton having them reworked to be streetable. i loved them. i might have to find a weber intake for my chevy!!
What kind of cfm am I looking for on a straight six? I want to get the most out of it without overkill.
http://golenengineservice.com/calc/calccarb.htm http://wps.com/LPG/LPG-carb-size.html The first link is an actual calculator for figuring it out. The second shows the formula and explains it a bit.
That's a good question, which venuri are in there? it seems that will make quite the difference. Though I did find a link that talked about the 40DCOE and how it flowed better with the 32mm choke than the 45DCOE did with the same choke. Though I couldn't find any actual figures for the DCOE...
It doesn't frost up but it will sweat on a humid day. I am wondering how it will due when I go with bigger carbs. May have to reengineer. My buddy has a pair of Dellorto DRLA 45s we are going to try. Those things are huge compared to the ones I have on there so I am anxious to see what they will do.
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