Converter stall speed on a 727 trans

[coyote42]

Looking for info on stock converter stall speed on a 66 727torqueflite VS 67 and up 727. I know the 66 input shaft and converter are not interchangeable with 67 up. I have a 66 trans to use and may have the converter rebuilt. Its going into a 340 67 cuda.

 

[Garys1969RR]

All I know is that Torque Converter stall speed is partly determined by 3 (or more) factors. 1-The amount of torque that the engine is making. 2-The diameter of the torque converter. 3-The way the blades inside the torque converter are positioned. And there are 3 sets of those I believe. Impeller, stator, and the driven set that are connected to the engine. My 451 has an 11" diameter converter, and has been opened up and modified for a higher stall speed. But it will stall at a higher RPM on my 451 than it would behind a low torque 361 for example. And it seems to have a max stall speed of 2200 to 2500 RPM. So if you want a higher stall, go smaller diameter, and have it modified. Or buy one thats designed to stall at higher speeds. Hope this helps. C Ya

 

[68 Sport Satellite]

I am building a street driven 451. I was going to stay under 2600 on stall speed but am just figuring all this out. I didn't want to go too high and have drivability issues with the car rolling backward on a hill etc. is your 11" converter performing as you would like?

 

[Garys1969RR]

I am building a street driven 451. I was going to stay under 2600 on stall speed but am just figuring all this out. I didn't want to go too high and have drivability issues with the car rolling backward on a hill etc. is your 11" converter performing as you would like?

Hi 68, yea it is working great! And I have another 11" that also worked fine in my 440. It leaves the starting line fast at the track, and also works good on the street. No rolling back unless a real steep hill. I'm using the 11" one that they used to call the Street Hemi converter. Because stock 383/440 Magnums had the larger 12" converter. In a stock 440, the 12" stall about 1200 RPM. While the stock 11" stalls around 1800 or 2000 RPM. Re worked closer to 2400 RPM.

 

[RustyRatRod]

I think they will be about the same on either side of the split. Usually, the stock Mopar converters stalled at "around" 1500-1700 RPM. That's high in comparison with other automakers, but Mopar knew what they were doing. The factory high stalls were generally right at 1000 RPM more.

 

[68 Sport Satellite]

Hi 68, yea it is working great! And I have another 11" that also worked fine in my 440. It leaves the starting line fast at the track, and also works good on the street. No rolling back unless a real steep hill. I'm using the 11" one that they used to call the Street Hemi converter. Because stock 383/440 Magnums had the larger 12" converter. In a stock 440, the 12" stall about 1200 RPM. While the stock 11" stalls around 1800 or 2000 RPM. Re worked closer to 2400 RPM.

So why not just go with a smaller converter like 10" to already be at 2400 without reworking?

 

[RustyRatRod]

So why not just go with a smaller converter like 10" to already be at 2400 without reworking?

You sorta have to be careful with that. The diameter of a converter doesn't necessarily have a thing to do with stall speed. ....at least not anymore. It used to, but now with modern converters, you can have almost any size or stall you want. For example, we run a 12" in our Buick nostalgia front engine dragster so as not to shock hell outta the tires. It stalls at around 5500, but we wanted the extra weight to act as a cushion.

 

[68 Sport Satellite]

You sorta have to be careful with that. The diameter of a converter doesn't necessarily have a thing to do with stall speed. ....at least not anymore. It used to, but now with modern converters, you can have almost any size or stall you want. For example, we run a 12" in our Buick nostalgia front engine dragster so as not to shock hell outta the tires. It stalls at around 5500, but we wanted the extra weight to act as a cushion.

so what's a good modern convertor brand, size, and stall speed that would work well for my primarily street driven 451 motor? I'm thinking 2400-2600 rpm stall? Not sure about the rest. I'm looking for a good brand too that will be long lasting and good performance.

 

[RustyRatRod]

Call these folks.

http://gopnh.com/

They are who we deal with for everything except the race only converters. Rodney even has one of theirs in his 5300 pound Fury wagon that runs 8.40s in the 1/8. Other than them, we use PTC, but Precision can handle exactly what you need and probably be very reasonable.

so what's a good modern convertor brand, size, and stall speed that would work well for my primarily street driven 451 motor? I'm thinking 2400-2600 rpm stall? Not sure about the rest. I'm looking for a good brand too that will be long lasting and good performance.

 

[383man]

I hear good things about PTC converters and they are priced nicely. Myself I run a 9.5 Luppo Dynamic street/strip converter that they built me. It drives great on the street like a normal converter and flashes about 4200 at the track. Usually the smaller converters like the 8" are in mainly race cars with alot of stall but you have to watch the converter efficiency on the top end so you dont loose to much mph. The bigger 9 and 10" will have better mph many times but not as good of a stall as the smaller but it depends on the combo. Thats why its always good to call a good converter company and tell them your full combo. Is this going to be a street/strip car or just a driver ? Ron