904 Converter? Stock stall with 350lbft torque?

[Kicker92]

I have a A904 converter that is black with the numbers 762 painted in orange on the front.
Looks to be about 11" diameter.

I would believe that this is a factory unit since I don't think the tranny had been out of the car before I bought it.

Question:
When feeding that converter with around 350lbft of torque behind a built 360, what stall speed could be expected?

I think the old 318 used to stall around 1,800 rpm, but this with be a lot more torque...


Thanks,

Ryan

 

[318willrun]

318's had 340 ft lbs (gross) of torque. Anyways, it will be more..... and I hope you have a balanced flexplate

 

[Kicker92]

Thanks, I will weld on the balance weights if I use it. Trying to figure out if it'll be 2200+, or still lower?

To clarify, the 350lbft should be around 2000 rpm, it'll peak at about 425lbft into the powerband.
I understand that the stall rpm will increase with more torque / resistance applied, but was hoping someone might know what the upper range of these stock converters are?

Did they ever do a 904 with this converter behind a HP 440?

 

[318willrun]

Thanks, I will weld on the balance weights if I use it. Trying to figure out if it'll be 2200+, or still lower?

To clarify, the 350lbft should be around 2000 rpm, it'll peak at about 425lbft into the powerband.
I understand that the stall rpm will increase with more torque / resistance applied, but was hoping someone might know what the upper range of these stock converters are?

Did they ever do a 904 with this converter behind a HP 440?

no 440 came with a 904 behind it.
I've had 318 2bbls stall up to 2100 with stock 904 converter. You should have no problem pushing 2200 "brake stall" with a 360. I think you could balance a flex plate much cheaper than a converter, but thats up to you.

• And to clarify, 318 2bbl's had 340 ft lbs of torque at 2400 rpm's, not that far off from what you are talking.

 

[Kicker92]

Thanks for the info, I didn't realize how low rpm the torque curve is on the 318's!

I dug through a bunch of old paperwork, and it turns out that the original owner had the tranny rebuilt in the 80's, and they installed a refurb TC. That explains why it's black and has the 762 numbers.

Found this on another site for the "762":

762 - A904 TORQUE CONVERTER

A904 TF6
11" DIAMETER (10" BOLT CIRCLE)
1.810" PILOT, 27 SPLINES
4 OFFSET PADS, NON LOCK-UP
1700-2100 STALL, 122T GEAR
NO WEIGHTS

CODES:
LOW STALL STICKER
1968-76

 

[RustyRatRod]

I would "guess" probably around 2200-2500 "or so".

 

[transman]

Nice looking Demon you've got. On the converter, I would, like RRR guess somewhere in that 2200+ range.
On that note, why trust something built 30+ years ago. It was probably built by the converter division of Man Mac transmissions who are no longer around.
You've invested a lot of time and money into the engine, so don't cheap out on the converter.
Call Paul at T.C.S., 604-533-8675, give him all the specs you've got, tell him what your plans for the car are and he'll get you the right converter.

 

[Kicker92]

Hi transman, it's funny you should say that! I literally just got off the phone with Paul @ TCS.

I have their 904-10-SPS converter from the old car as a second option to the stock one, but looking for a lower stall to use with autocross & track days.

Need to get that car together with the TCS converter, and see how it works out first.
Will probably just get rid of this stock one.

 

[transman]

Hi transman, it's funny you should say that! I literally just got off the phone with Paul @ TCS.

I have their 904-10-SPS converter from the old car as a second option to the stock one, but looking for a lower stall to use with autocross & track days.

Need to get that car together with the TCS converter, and see how it works out first.
Will probably just get rid of this stock one.

Just get a stock converter from T.C.S. for your 360.

 

[dibbons]

From 1972 Plymouth FSM:

Does †his mean a 318 can have a higher/equal stall speed than/as a larger motor, if the larger motor had a torque peak at a higher rpm than the 318 (assuming the same/equal torque convertor)? For example, according to the above chart, the 318 and 340 with 10 3/4" convertor have about the same stall speeds listed.

 

[RustyRatRod]

Nice looking Demon you've got. On the converter, I would, like RRR guess somewhere in that 2200+ range.
On that note, why trust something built 30+ years ago. It was probably built by the converter division of Man Mac transmissions who are no longer around.
You've invested a lot of time and money into the engine, so don't cheap out on the converter.
Call Paul at T.C.S., 604-533-8675, give him all the specs you've got, tell him what your plans for the car are and he'll get you the right converter.

Great advice.

Quick story on that. I have a regular customer whose a Chevy guy. He's a good dude, but this guy is the corner cuttinest **** you'll ever meet. He was askin me about converters. I told him if it was me, I would call a major converter maker and get a custom one made, because the converter was the number 1 thing in an auto car to get right.

He says "I ain't buildin a race car, I found one at Summit for 150 dollars". I said, Ok, that's good then!

LOL

 

[dibbons]

Interesting quote from allpar.com:
"In lay terms, a vehicle is geared to allow the cruising speed (65-70mph) to be about 200 RPM above the torque peak of the engine (at that time around 2,000-2,500rpm). This allows the engine to reach rated torque on grades of 6%, without losing speed."