[dukemd66]

Someone explain to me what torque and or stall converters are.
I just broke down a 327 I built in high school 20+ yrs ago and the cam I put in for no specific reason except back then the bigger the better, was a "CC 280h." I am assuming that this is a competition cam. Reading the specs on the cam and info they rec a stall converter.
Please remember that 20 yrs ago I did not know jack about building a motor and I barely know jack now.
It is/was a 327 .030, Holley street performer manifold, 461 camel hump heads, TH350, Holley 600 carb, with the above mentioned cam. I am just trying to decide what to do with my motor/trany unit. Get a crate motor, keep my block and change cam/heads, keep cam change heads etc....

[Oldani Motorsports]

A torque converter consists of three main items; the pump, the turbine, and the stator. The converter pump is the shell of the converter and spins at engine speed. The turbine is splined to the input shaft. The stator sits between them, with a sprag whose inner race is splined to the support tube that sticks out of the front pump around the input shaft. As you take off, the pump speed increases and fluid that is fed to the converter via the valve body begins to move around and around, from the primary pump through the turbine via the stator which multiplies torque with its combination of fin number, shape, and angle. As turbine speed catches up to pump speed the sprag allows the stator to freewheel when fluid flows against the opposite side of the stator. Thus, when you hear of a broken sprag that is why it feels like taking off in high gear, as the stator freewheels all the time and is not able to multiply torque. The fin angle of the primary pump can be changed to control stall speed characteristics along with the stator. Generally the smaller the converter the higher the stall speed can be made with it. A good converter will use furnace brazed fins and a quality sprag. Some may have anti-ballooning plates on the front and rear halves too, while some even use an investment cast steel front on them for superior strength. Using the combinations of physical converter size, fin angle, and stator, you can build just about any combo needed for a particular situation. That is a basic quick story on converters, but there is much more to them than that if you want to get in depth on the hows and whys of various sizes, stators, and fin angles, etc. Your combo should work pretty well with a converter that stalls in the area of 2500, or a little more. If you need more info you are welcome to email me! [img]smile.gif[/img]

[dnult]

A torque convert is like a fan blowing on another fan. The powered fan will force the driven fan to turn by the movement of air between the two. A torque converter is very much the same except it moves oil instead of air. Also, the fan blades are built so they maximize the energy transfer between the drive and driven element.

A phenominon of torque converts are that once they reach a certain speed with the driven element is held stationary (via the wheels), the driven element can't be turned any faster. This speed is known as the stall speed. In a stock unit, the stall speed is about 1200RPM.

A stall converter is really the same thing as what is called a torque converter. When people talk about stall converters they are just referring to a converter that stalls at a higher speed that a stock unit.

To maximize performance, (or overcome a boggy bottom end due to the camshaft choice) a higher stall will be chosen to get the engine higher up in the power band. I've got a SBC350 with the Edelbrock Performer RPM kit in it. The motor just doesn't run well below 1500 RPMs or so. With a stock converter it's difficult to keep the engine running, particularly when it is cold. I'll be installing a converter that stalls closer to 2250 or 2500 RPM to prevent a bog problem I have with my engine setup. I will also see a performance improvement since this new stall speed will help me take advantage of the new power band from the Edelbrock equipment.