Converter Stall Speeds

[67 B-body]

OK,
My car runs like a Raped Ape, but I'm wondering how everyone else determins the Correct stall speed for there car?
When I foot brake mine, it doesn't seem to get anywhere neer the supposed stall speed of the convertor before it just starts pushing the car beyond its breaking ability. I let off the brakes at this point and get into the throttle hard, but it's obvious I'm not into the real power yet! After a reletively short roll out the engine REALLY comes to life and pulls you back into the seat even harder.. Launches are strong, but I know it has a LOT more to give if it were in a higher RPM range before letting off the brakes.
The converter I have is a Coan brand, and rated at 3800 rpm, but doesnt seem to be getting their... I thought about sending it in and having it re-worked for a 4800 stall speed, but I might just look for a used one and sell what I have. This convertor would be good for a car that needs something around 2700 - 3000 rpm, not my car!
I'm certain the Ol' Plymouth will carry the front wheels with a new "higher stall" converter, and seems to be coming close to doing so now, so I'll have to be doing some real sweet talking to the wife! She's ready for me to stop spending money now!

 

[Cranky]

What you are experiencing is called 'brake stall' and is not the 'true' stall of the converter. Here's a good read....
http://www.carcraft.com/techarticles/selecting_right_torque_converter/index.html

 

[Stumper]

Good article Cranky!

 

[shag766]

What you are experiencing is called 'brake stall' and is not the 'true' stall of the converter. Here's a good read....
http://www.carcraft.com/techarticles/selecting_right_torque_converter/index.html

good article cranky. when i pulled the 318 out it had an art carr tranny on it.

 

[Cranky]

Stalls will usually go up when you put more torque in front of it too so one that's advertised at 3800 may not see that unless the engine can produce enough torque and still hold the car in place with the brakes. That may be the case here but a lot of times, the the engine will over power the brakes before the engine can make the converter come up to it's full stall. Hey 67, how bout listing what your engine has in it? And thanks for the cudos! Chevy Craft and Shot Rod sometimes have really good articles in them Btw, are your brakes standard or power? If they are power, that may be your problem...

 

[Budnicks]

If it's a strip/track only car, I would pick your converter stall speed, by were your making the peak or near peak torque within a couple of hundred RPM's or as high as possible near freeway speed RPM's for street use, it will launch much harder... Also with higher altitudes, lighter cars, smaller engines & lower gears like 4.10:1, 4.30:1, 4.56:1 or steeper {for example}, the stall speed is effectively less, because of the effects of torque multiplication factors {moving the car easier}, unless you have a trans brake of coarse... Higher gears like a 3.23:1, 3.55:1 or higher {for example}, will give an effectively higher effective stall speed than advertised, especially off a foot brake or heavy cars... That has been my experiences anyway...

 

[67 B-body]

Stalls will usually go up when you put more torque in front of it too so one that's advertised at 3800 may not see that unless the engine can produce enough torque and still hold the car in place with the brakes. That may be the case here but a lot of times, the the engine will over power the brakes before the engine can make the converter come up to it's full stall. Hey 67, how bout listing what your engine has in it? And thanks for the cudos! Chevy Craft and Shot Rod sometimes have really good articles in them Btw, are your brakes standard or power? If they are power, that may be your problem...

Manual brakes Cranky...
It has loads of torque and Horsepower, Just wants to pull the car beyond the brakes when bringing it up in RPM.... Like it's too tight.
I can't remember wht thread I showed my build in, so I'll give the basics to ya.

440 bored .030"

Standard stroke steel crankshaft

Studded mains with Girdle

Scatt H-Beam Rods

Forged .140" Domed pistons with trough type valve relief "-14cc volume if memory serves"

.040" compressed Fel-Pro head Gaskets

Victor 440 type heart shape chamber heads "75cc", With Light porting work.

MP .590" Solid camshaft

1.6 to 1 ratio Rocker Arms

Victor 440 intake

Holley 850 DP

10 gal fuel cell with 1/2" aluminum fuel line, -10AN braided at each end.

140gph electric Fuel Pump.

TTI 2" primary headers 3 1/2" collector size.

Stainless exh to the axle into flowmasters.

727 trans with Cheeta Reverse pattern Valve Body

Coan Convertor previously mentioned

 

[67 B-body]

If it's a strip/track only car, I would pick your converter stall speed, by were your making the peak or near peak torque within a couple of hundred RPM's or as high as possible near freeway speed RPM's for street use, it will launch much harder... Also with higher altitudes, lighter cars, smaller engines & lower gears like 4.10:1, 4.30:1, 4.56:1 or steeper {for example}, the stall speed is effectively less, because of the effects of torque multiplication factors {moving the car easier}, unless you have a trans brake of coarse... Higher gears like a 3.23:1, 3.55:1 or higher {for example}, will give an effectively higher effective stall speed than advertised, especially off a foot brake or heavy cars... That has been my experiences anyway...

4:10 ratio 8.75" Rear end

 

[67 B-body]

This is what the computer says

1st Run


SHORT BLOCK


Block: Chrysler 440 Bore: 4.350 in Stroke: 3.750 in
Cylinders: 8 Cyl Vol: 913.27 cc Total Vol: 445.9 ci


CYLINDER HEADS


Cylinder Heads: Victor no mods
Airflow File: no mods.flw
Intake Valves: 1 Exhaust Valves: 1
Intake Valve: 2.200 in Exhaust Valve: 1.810 in

COMPRESSION


Compression Ratio: 13.00 Combustion Space: 76.11 cc


INDUCTION


Induction Flow: 850.0 cfm @ 1.50 inHg Fuel: Gasoline
Manifold Type: Single-Plane Manifold N20: 0.0 lbs/min

Blower: None : *** %

Flow: *** cfm Pressure Ratio: *** Boost Limit: *** psi
Speed: *** rpm Belt Gear Ratio: *** Surge Flow: *** cfm
Eff: *** % Internal Gear Ratio: ***

EXHAUST


Exhaust System: Large-Tube Headers Open Exhaust


CAMSHAFT
Camshaft Type:MP .590" @ 1.6 ratio: ***
Lifter: Solid Lobe Center: 108.0
Cam Specs @: 0.050-Lift Valve Overlap: 55.0
Int Lift@Valve: 0.600 in Int Duration: 271.0
Exh Lift@Valve: 0.600 in Exh Duration: 271.0
Nominal Timing Timing@ Adv(+)/Ret(-): 2.0

IVO (BTDC): 27.5 IVC (ABDC): 63.5 IVO: 29.5 IVC: 61.5
EVO (BBDC): 63.5 EVC (ATDC): 27.5 EVO: 65.5 EVC: 25.5
ICA (ATDC): 108.0 ECA (BTDC): 108.0 ICA: 106.0 ECA: 110.0




CYLINDER HEAD AIRFLOW DATA
Description: Victor no mods

Intake Valve Exhaust Valve
Test Diameter: 2.200 in Test Diameter: 1.870 in
Pressure Drop: 1.0 inH2O Pressure Drop: 1.0 inH2O
Lift: in Flow: cfm Lift: in Flow: cfm
0.100 71.1 0.100 54.1
0.200 146.2 0.200 103.0
0.300 207.9 0.300 150.0
0.400 251.1 0.400 187.0
0.500 273.6 0.500 213.2
0.600 287.2 0.600 229.8
0.700 296.0 0.700 239.4
0.800 296.0 0.800 246.4
*** *** *** ***
*** *** *** ***




CALCULATED POWER AND ENGINE PRESSURES




Engine Power Torque Int Man Vol IMEP FMEP BMEP
RPM (Fly) (Fly) Pressure Eff % Pressure Pressure Pressure

2000 227 477 14.64 78.8 202.6 19.3 163.6
2500 254 445 14.60 75.1 188.1 21.0 152.7
3000 301 452 14.58 77.9 188.6 22.8 155.0
3500 368 483 14.53 83.7 200.3 24.7 165.7
4000 446 521 14.45 89.5 216.0 26.7 178.6
4500 522 548 14.35 94.2 228.1 28.9 187.9
5000 585 559 14.23 97.0 234.3 31.2 191.6
5500 639 559 14.11 98.4 237.0 33.6 191.9
6000 683 551 13.99 99.1 236.6 36.2 189.1
6500 699 524 13.86 97.4 229.4 38.8 179.8
7000 719 503 13.77 95.8 224.7 41.6 172.7
7500 722 474 13.68 94.6 216.9 44.6 162.6

 

[Cranky]

What do you have on it for brakes? Is it sliding the front tires or are they rolling. Had a car with 11" drums all the way around and a 4500 converter and even with the skinny front runners, it stayed put. Sounds like your engine is producing enough torque to overcome your brakes and not allowing the converter to come up all the way but imo, you don't have enough converter anyways...and it may too tight. About the only way to truly test it is to lock the car down and nail it. Does it have a manual valve body in the trans? If so, you can run about 15-20 mph in high gear and nail it for a couple of seconds and watch the tach. That should give you an idea what the converter is doing.

 

[67 B-body]

What do you have on it for brakes? Is it sliding the front tires or are they rolling. Had a car with 11" drums all the way around and a 4500 converter and even with the skinny front runners, it stayed put. Sounds like your engine is producing enough torque to overcome your brakes and not allowing the converter to come up all the way but imo, you don't have enough converter anyways...and it may too tight. About the only way to truly test it is to lock the car down and nail it. Does it have a manual valve body in the trans? If so, you can run about 15-20 mph in high gear and nail it for a couple of seconds and watch the tach. That should give you an idea what the converter is doing.

Good idea.... Maybe today when I'm out driving I'll do that. Never the less.... I'm certain I can use higher than what I have. I dont like it when everything is so torqued, twisted up and hard up on brakes, just to try getting a few more RPM before launching.
I am impressed with how well the new Hoosiers are working with the new SS springs! little to no tire spin,,, just forward motion and a lot of sitting you back against the seat, then you better be ready to hit second gear! Shifting comes up a LOT quicker than my 69 RR ever did, and it ran mid 12's.
Like I said, it launches pretty hard and seems to have the feel of taking off all over again when the RPM power band hits just after a very short roll out!
I have only put it to the floor a couple times from the start, because I still haven't got the warm and fuzzy that everything will hold up to the engine... LOL!

 

[67 B-body]

BTW,,, I haven't shoved the front tires Cranky. I think the brakes front and rear are holding pretty equally,,, untill they give up!

 

[67 B-body]

Well,
I went out for a quick run out of town with the car. I thought I would lay into it and see what it would rev to on launch..... I pumped up the brakes and eased into it up to about 2700 RPM and less than half throttle. The rear tires were now on the verge of spinning! I let off the brakes and hit the gas and tires started spinning! I shifted into second and the tires were still breaking loose and the car started to go sideways.... I then let off for a moment and shifted into third and slowed things back down a bit.....
I hope heating the tires up will allow me to launch better than that!!!!! Boy what a differance between in town half throttle jabs and launching hard out on a country road!!!
Even though it didn't hook well, things started to go by VERY quickly and second gear came up faster than ever!!! I'm still smiling!!!!!

 

[SUPERSTOCKRACER]

What do you shift your car at?
I like a converter to stall around 700-800rpm below that rpm.

 

[67 B-body]

What do you shift your car at?
I like a converter to stall around 700-800rpm below that rpm.

I plan on shifting at 6500 - 7000 on the strip, but also use it on the street well below that.... I'm guessing at 55mph I'll be reving around 3700rpm.

 

[67 B-body]

I'm just hoping to launch hard enough to let the engine work,,, and run mid 10's!
Maybe I'm not going to hit those numbers,,, then again maybe it will? I also realy want to say my car can lift the front tires... LOL! My 69 RR never mustard up enough power to do that,,, But it wasn't anything close to what I have in this engine!

 

[383man]

67-b-body your build is close to mine in my 63 Sport Fury but I have a 4.15 crank for 493 cubes. I use Indy EZ heads and have a dished piston for 10.6 comp. My cam is a custom grind thats close to the .590 as with 1.5 rockers it has .585 and .592 lift and its 264 and 270 at .050. But I am using 1.6 rockers. I run the Indy dual plane intake and use an 850 DP. 2" TTI headers and 3" pipes out to bumber. My converter is a 9.5 Dynamic unit that will flash about 4200 but on the line I foot brake it to 2200 to 2400. Much more and it will skid thru the lites. I have the stock power drum brakes on my car. But it launches nice as this weekend was only the second time I have run this combo and it pulled a 1.50 sixty ft leaving like I said with a 10.76 pass.
Also dont worry about not hooking on the street as my car dont hook on the street at all either. But at the track I always try to line up in the tread marks where everyone is launching and it hooks good enough to get about 6 inches of air like that. Ron

 

[67 B-body]

67-b-body your build is close to mine in my 63 Sport Fury but I have a 4.15 crank for 493 cubes. I use Indy EZ heads and have a dished piston for 10.6 comp. My cam is a custom grind thats close to the .590 as with 1.5 rockers it has .585 and .592 lift and its 264 and 270 at .050. But I am using 1.6 rockers. I run the Indy dual plane intake and use an 850 DP. 2" TTI headers and 3" pipes out to bumber. My converter is a 9.5 Dynamic unit that will flash about 4200 but on the line I foot brake it to 2200 to 2400. Much more and it will skid thru the lites. I have the stock power drum brakes on my car. But it launches nice as this weekend was only the second time I have run this combo and it pulled a 1.50 sixty ft leaving like I said with a 10.76 pass.
Also dont worry about not hooking on the street as my car dont hook on the street at all either. But at the track I always try to line up in the tread marks where everyone is launching and it hooks good enough to get about 6 inches of air like that. Ron

Very cool!
I use the MP 590 cam, but also have 1.6 rockers That makes it a .629" lift, but when you subtract the valve lash, your back down to around .600" just a bit over that, but close enough to say 600 when asked.
I here a lot of folks comparing camshafts, but never take into account the lash when calculating things....
I like the thought of 6" between the tire and track!!!! Hows your suspension setup? Do you realy feel the power band come in when your car rolls out, or is it strong down low with the stroker setup?
Thanks!!!!

 

[shag766]

holl poop, you alredy have all the big guys in. X2

 

[67 B-body]

holl poop, you alredy have all the big guys in. X2

LOL,,,, sorry, you've lost me on that one.... I'm sure it's something cool,,,, I just dont get it...LOL :edgy: