I am beginning to wish I had not started this thread
After seeing the intake in the catalog, I was curious if anyone had tried it.
If I owned a 235 or a 261, and could find one of the intakes, I would try it; but I have a wider selection of carburetors to play with than most who will read this thread.
JW - you guessed correctly on better distribution.
Now as to a size GUESTIMATE:
I will bow to Jerry's expertise on a maximum RPM (and Jerry, as I previously posted, I think three 500 Holleys are way too much), and thus use 5000 for the calculations.
For a 235, I would TRY 2-barrel carbs of approximately 225 CFM; for a 261, those of about 250 CFM. Should be able to find various size Stromberg WW's to try.
And where do these numbers come from??? Well, did you ever hear of an ouija board?
I would have used my crystal ball, but I dropped it!
Actually, most are familiar with the CFM "equation" that CFM = (CID x RPM) / 3456.
But the above is not the complete "equation".
The above is more or less accurate for 4-cycle multiple cylinder engines WITH A LEAST 4 CYLINDERS. As most folks are concerned with either a 6 or an 8 this equation generally applies.
For engines with less than 4 cylinders, the equation is modified as: CFM = [(4/N) x (CID x RPM) ] / 3456 where N is the number of cylinders.
When dealing with the IR design, while one is still dealing with a 6 cylinder; for the purposes of calculating carburetor size, one is dealing with three 2-cylinder engines.
Thus the 235 may be thought of as three 78 CID 2-cylinders, whereas the 261 as three 87 CID 2-cylinders.
Plugging in the numbers (again, using Jerry's 5000 RPM)
For the 235 we have CFM = (4/2) x (78 x 5000) / 3456 is equal to 225 for each carb
For the 261 we have CFM = (4/2) x (87 x 5000) / 3456 is equal to 252 for each carb
PS: Clifford also makes single 4-barrel intakes.
Jon
