330jetstar

I'm switching to a 4 barrel intake and carb do I need this?

Fun71

What year end engine? It may be the transmission electric kickdown switch.

330jetstar

1964

mrolds69

What Kenneth said, it IS definitely a trans kick down switch. If your car is automatic + stock, you need it.

330jetstar

How do I mate this to the 4 barrel properly

oldcutlass

Mount it so it engages at full throttle.

joe_padavano

THIS is why you need a factory Chassis Service Manual.

Note that the 1964 330 has TWO switches to control the trans. This switch operates at wide open throttle and activates both the kickdown and the switch pitch torque converter. There is a second switch built into the dashpot in front of the carb throttle arm that also controls the switch pitch converter at idle and low speeds. The yellow and black wires running from the kickdown switch towards the front of the motor in your photo are connected to this second switch.

MDchanic

Still sure you want to install that 4-barrel?



- Eric

330jetstar

Yes a 4 barrel is going on. Worst part is I want to switch to a 2004r trans in the future not sure if i would need this kickdown or a different one for the 2004r.

330jetstar

Im currently rebuilding the engine and getting near finished. The shortblock is coming together and starting to thing about getting it running again. Looks as though I will be running into some delays.

MDchanic

Then do both at the same time. The 200R4 uses a TV cable, which is a completely different type of kick-down.

- Eric

330jetstar

I can't. I'm having a hard time finding one. Once I do find one I will want to rebuild it and get all proper parts to hook it up. Hopefully this winter. Probably next year. For now sticking with the stock trans.

oldcutlass

If you mount the switch so it is fully activated at wot, I think the switch pitch portion will fall into place.

MDchanic

A 200R4? Really? They are not uncommon by any means.



If I may make one recommendation, it would be to keep the perfectly acceptable 2-barrel for now, and not change it until you change the transmission as well, so that you only have to deal with creating non-stock automatic transmission linkage one time.

Also, bear in mind that, according to the standard calculations, your 330, revving to its maximum power at about 4,500 RPM, with an 83% efficiency rate, will need about 356 CFM.
A large flange 2-Jet (others please correct me if the 330 got a small-flange unit) will pass between 352 to 435 CFM, depending on venturi size, so that fancy four barrel is not likely to improve your performance very much anyway.

Good luck!

- Eric

joe_padavano

The problem with these calculations is that 2bbl and 4bbl CFM ratings are taken at different pressure drops across the carb. The 2bbl rating uses a higher pressure drop, which produces a larger CFM rating than if it were tested at the 4bbl pressure drop.

330jetstar

Was just going with a 450cfm 4 barrel.

joe_padavano

A 330 wants at least a 600 CFM carb. Frankly, I'd go Qjet.

MDchanic

Joe, why such a high number?

Do you do the math differently, use different numbers (RPM?), or do you speak solely from experience, discarding the standard formula as meaningless in the real world?

- Eric

330jetstar

I may get a bit bigger of a new quick fuel carb. Or something used and rebuild it.

joe_padavano

Because the calculations you are using are idealized steady state with no pressure drop across the carb. The reality is that the actual flow rate of a carb (or any orifice) is dependent on pressure drop. As mainfold vacuum level approaches atmospheric (during WOT acceleration, for example), carb flow rate drops. In addition, car engines rarely operate at steady state. It's these transient conditions (like accelerating at WOT) that are usually the sizing cases. Real world tests repeatedly show better performance with a carb that's larger than the ideal calculations would indicate. Also keep in mind that the wet flow of fuel in the airstream knocks down the CFM of the air by about 8%. Finally, carb size obviously depends on carb type (mechanical secondaries, vacuum secondaries, or air valve secondaries like a Qjet or Ebrock). Obviously the latter two are more forgiving as far as "oversizing" is concerned.

MDchanic

Makes sense. I'll keep it in mind.

Thanks, Joe.

- Eric

mrolds69

Right...like Joe said there are TWO switches, one for the switch pitch and one for the detent. The switch pitch one is a pretty precise set up, at least on my Buick. If the car downshifts well now, personally..I wouldn't try to put a 4bbl on it at this point unless you could find the right 4bbl + manifold. If you put a 4bbl on it and lose your passing gear or SP capability, it's not going to be as much fun to drive, and it's going to use more gas. If you can change the trans + 4bbl at the same time, it's going to be easier to do. Don't think the 4bbl is going to turn it into a race car.

joe_padavano

Actually, to be completely correct, the large switch operates BOTH the kickdown and the switch pitch at WOT for passing. The small switch ALSO operates the switch pitch, but at idle and low RPM for added torque multiplication off the line.