Stall speed

[dammstrate]

Is there any way to tell or estimate the stall speed of a converter without taking the trans out and looking at a part number?

 

[Aron Gleason]

What i was told, is to have the car in 3rd gear at about 5 mph then stab the throttle and where the tach stops is what stall you have.

 

[PRHeads]

Does it have a manual valve body?

If so, get it high gear rolling along steady at about 15-1700rpm.
Stab the throttle, the tac will jump right up to a certain rpm and then pause there. That’s the effective flash stall speed.
It only takes a few seconds.

If it has a std valve body, you need to remove the kick down linkage from the carb before doing the test.

Do it somewhere that has decent traction.

 

[Fran Blacker]

Don't drive around with Kickdown disconnected, put it back on.

 

[RJRENTON]

Is there any way to tell or estimate the stall speed of a converter without taking the trans out and looking at a part number?

WHY not define EXACTLY what torque converter stall speed is....... All the preceding tell how to check and or measure the stall speed. I thought STALL SPEED or stall rpm means the RPM of the converter is at maximum pump rpm and zero turbine rpm with stator or one one way clutch just starting to move, thereby MAXIMIZING the converters torque multiplication factor. The higher this number allows the engine too operate at a higher in its torque curve band, depending on cam and rear gear ratio. PLEASE....ENLIGHTEN ME as to the how's and why's this occurs......and why this is good to know......
BOB RENTON

 

[j-c-c-62]

WHY not define EXACTLY what torque converter stall speed is....... All the preceding tell how to check and or measure the stall speed. I thought STALL SPEED or stall rpm means the RPM of the converter is at maximum pump rpm and zero turbine rpm with stator or one one way clutch just starting to move, thereby MAXIMIZING the converters torque multiplication factor. The higher this number allows the engine too operate at a higher in its torque curve band, depending on cam and rear gear ratio. PLEASE....ENLIGHTEN ME as to the how's and why's this occurs......and why this is good to know......
BOB RENTON

Because the real stall speed is based on the engine's performance, and every car/engine combo is different. Advertised stall speeds are likely just an estimate mean for a typical combo. Testing one's combo tells an owner what they need to know. How can you not know that?

 

[RJRENTON]

Because the real stall speed is based on the engine's performance, and every car/engine combo is different. Advertised stall speeds are likely just an estimate mean for a typical combo. Testing one's combo tells an owner what they need to know. How can you not know that?

I was under the assumption that the stall speed of the converter is selected for the use the car will see, then the engine's cam, etc rear gear are selected to maximize the vehicle's acceleration capabilities not the other way........higher stall rpm generates a lot of heat and requires an external oil cooler.......just my thoughts and interpretation......
BOB RENTON

 

[Geoff 2]

B&M state in their catalog:
Stall speed is based on an engine producing 230 ft/lbs of tq @ 2500 rpm. Similar to average small block. More tq will provide higher stall #s.

 

[dammstrate]

Bunch of good information, thanks!

 

[beanhead]

Post #3 is how it's done...