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Torque converter recommendation?

Started by Jonas_N, September 23, 2019, 07:25:31 AM

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Jonas_N

What would the recommended Torque Converter specs be for a heavy street car with 3.23 gear?

Engine I am building:

Cam: (HR)
Advertised Exhaust Duration      308 deg
Advertised Intake Duration              300 deg
Exhaust Duration at .050 inch Lift   248 deg
Exhaust Valve Lift                      0.363 in
Intake Duration at .050 Inch Lift      240 deg
Intake Valve Lift                              0.360 in
Lobe Separation   112 deg

CR: 10.83:1

Challenger340

Quote from: Jonas_N on September 23, 2019, 07:25:31 AM
What would the recommended Torque Converter specs be for a heavy street car with 3.23 gear?

Engine I am building:

Cam: (HR)
Advertised Exhaust Duration      308 deg
Advertised Intake Duration              300 deg
Exhaust Duration at .050 inch Lift   248 deg
Exhaust Valve Lift                      0.363 in
Intake Duration at .050 Inch Lift      240 deg
Intake Valve Lift                              0.360 in
Lobe Separation   112 deg

CR: 10.83:1

Stroke/Size of the Engine is one of the most important factors in determining adequate Stall Speed ?

just say'in....
you put that Cam in a little 383 Engine with a BIG Intake you may require a 10" 3,500 stall ?

Try again with Stroke/Size of engine ?
440/3.75" ?   
493/4.15" ?
512/4.25" ?
Intake ?
actual Rear Tire Diameter in inches on the 3.23 cogs ?
Only wimps wear Bowties !

Jonas_N

Sure thing! :)

440 (0.30 bored over.)
3.75 stock stroke
Eddy RPM intake
275/60/R15 rear tires = Diameter of 26.77 inches.

Challenger340

11" or 2,800-3,000 should be fine at 10.8:1
I wouldn't go any looser on the 3,23, but it should drive/leave lights under normal loads fine.... highway cruise is good..... and "flash" to 3-3,200 with a bit of brake when mashed.

What's the elevation with 10.8 ?
Only wimps wear Bowties !

Jonas_N

Thanks.

Elevation should be 49ft.
Will run on pump gas. 98 Oct.

How does it work, am I straining the gearbox more if i go lower vs higher?

justcruisin

I think with a 3.23 gear and a cam that size you will be a little soft on the bottom end at light to med throttle, but if you can swing the 10.8 at sea level that will help. A 275/60R15 is around 28" tall. Don't cheap out on the converter, have a quality shop build you one, the gearing will load the converter. An 11" is the way to go, you will most probably still see a 7-10% slip at cruise so I would be fitting up a quality cooler.

Jonas_N

Thanks.
Interesting info.
Well I am not looking for a soft bottom as that is the engine thats in the car now.
New engine is still not in the car so there is s till time to think about the set up,cam etc, I could also change rear gearing (Always wanted to rebuild my rear end.)

Theoretically, what would be the qonsecuences of going down to 2500 stall? (Cam power band is advertised from 1500 to 6500.)

Challenger340

Quote from: Jonas_N on September 25, 2019, 12:43:11 AM
Thanks.
Interesting info.
Well I am not looking for a soft bottom as that is the engine thats in the car now.
New engine is still not in the car so there is s till time to think about the set up,cam etc, I could also change rear gearing (Always wanted to rebuild my rear end.)

Theoretically, what would be the qonsecuences of going down to 2500 stall? (Cam power band is advertised from 1500 to 6500.)

Cam power bands are nothing more than a theoretical guesstimate, and in the case of that Hydraulic Roller Cam ? 6,500 rpm is no more than a "pipe dream" at best !
let me guess here.... a 'Howards' ?
and,
"wheel" Dyno's being the biggest perpetrators of FALSE upper rpm power readings on Auto/Stall equipped Cars as the converter tries to go back into Rotary Flow as the Engine powerbond rolls over at higher rpm's ? and usually with HR Cams because guys erroneously "think" because the Cam card said "6.500" it should go there ? WRONG !
But enough about that... bottom line is never race "Cam Cards", either upper or lower "advertised" numbers are nothing but doo-doo.

The 512 at sea level with the 10.8 C.R. can utilize a tighter 2,500 stall on the 3.23's, and probably better for the highway ?
but again here,
that "2,500" is best "built" by making an 11" Converter body tighter..... as opposed to something bought "off the shelf" and advertised as 2,500 ?
Something "built" tight in an 11" body will also probably have furnace brazed fins, etc., which is just stronger for the 512 Torque curve application anyway.

Only wimps wear Bowties !

Jonas_N

Great info, thanks.  :cheers:

Ok, noted about the doo-doo numbers.
So building a converter is the recommendation, what are some recommended companys to build it.

The engine is not in the car yet, just gathering information on how to match the drive train.
I can laborate with rear gearing, i also have other Heads that would give me a compression of ~9.9:1.

The cam is Eddys hyd Roller. What are some better makers of Hyd Roller cams?

c00nhunterjoe

Hydraulic roller of any brand is not the problem. Hydraulic roller in a 50 year old block that the lifter bores were never designed to have a long body lifter in is the problem. To run a hydraulic roller in a big block mopar CORRECTLY will cost you another 1,000 dollars in machine work to install bushings. Toss the hyd stick and put a solid in it, and dont skimp on the lifters if this is an idled street car.
   As for a converter, i have run quite a few custom converters and select has been my favorite. Call and ask for ed.

BSB67

Quote from: Challenger340 on September 25, 2019, 08:33:21 AM


The 512 at sea level with the 10.8 C.R. can utilize a tighter 2,500 stall on the 3.23's..........

Something "built" tight in an 11" body will also probably have furnace brazed fins, etc., which is just stronger for the 512 Torque curve application anyway.


What 512?  I think its a 0.030 over 440.

500" NA, Eddy head, pump gas, exhaust manifold with 2 1/2 exhaust with tailpipes
4150 lbs with driver, 3.23 gear, stock converter
11.68 @ 120.2 mph

Challenger340

Quote from: BSB67 on September 25, 2019, 07:30:40 PM
Quote from: Challenger340 on September 25, 2019, 08:33:21 AM


The 512 at sea level with the 10.8 C.R. can utilize a tighter 2,500 stall on the 3.23's..........

Something "built" tight in an 11" body will also probably have furnace brazed fins, etc., which is just stronger for the 512 Torque curve application anyway.


What 512?  I think its a 0.030 over 440.

Whoops, :brickwall:  That's what happens when a guy gets too many engine builds on the brain, this is a 440 NOT a 512.

Joe has used select ? so that might be best reference to follow ? and a really good idea to just give them a call, tell them what you are doing(440) and get their recommendation.

It's just that a Converter by "Committee" is sometimes just as bad as an Engine build by "Committee".... you get pulled in too many f-directions ?

If you want to rpm the thing on the Street ?
I'm ditto with Joe on going for a STREET Mechanical(Solid) Roller profile, and buying really good Lifters.
Again here, you need to make the distinction between the Street Solid Rollers being much easier on parts in the Street environment than the RACE Mechanical Rollers which are MUCH harder on Valve Springs over time.

A Street Solid Roller is designed for Street driving, and can be had in Tight Lash variants that once stabilized seldom require re-check and run almost dead nuts quiet.... and deliver far better upper rpm, power & Torque capability than ANY HR Cam ever thought of doing !
Only wimps wear Bowties !

Jonas_N

Quote from: Challenger340 on September 25, 2019, 09:48:51 PM
Joe has used select ? so that might be best reference to follow ? and a really good idea to just give them a call, tell them what you are doing(440) and get their recommendation.

Thanks for the tip, Will give Select a call when its time for the converter.