Torque Converter Advice

[james]

Running a 427 fe stroked to 482 (Barry's kit) in a 1964 Ford Falcon. This is strictly a street car and not for drag racing. The comp cam is 260 @.50 with solid lifters, c6 with manual valve body and I plan on using 350 gears. Any advice would be helpful and I'm also open to suggestions. Thank You!

[plovett]

Considering the weight of the car, the cam and engine displacement, the gearing, and the street usage, I'd say about 3500 rpm stall.

JMO,

paulie

[plovett]

Come on guys.  This is an interesting combination.  Big cam (high stall), large displacement (lower stall), light car (lower stall), numerically low rear gear (could go lower or higher stall), street use (lower stall).

What do you do?  I think around 3500 rpm stall would work good.  I'd recommend an auxiliary trans cooler.

The answers are easy when it's full-race or pure-street, but what about a combination like this?  This is an interesting question?

JMO,

paulie

[FirstEliminator]

    He could try a stock convertor, but all the neutral drops would be hell on the trans.   

  That much cam would need more stall than 3500. But, considering the rest of the application 3500 is probably the best bet. 

   

[jayb]

Its really not that big of a cam for a 482" engine.  If you call the converter companies, they will want to see dyno data if possible before making a recommendation.  Since it is street use only though, a 3000-3500 stall converter, probably a 10", is going to be the best option.

[james]

To be honest I am not that knowlegable about how stalls, gears, cams and rpm's work mathamatically speaking. I did see a formula that you times the rpm's (lest's say I shift at 6500) by the 25" tire size diameter and then divide that by 336 etc. So what if I went with (on one hand) 373 gears? And on the other hand went with 325 gears, what stall would I use in each case? My aim is not so much of a drag racing car but more of a freeway car. Thanks again for the advice. 

[e philpott]

I'm with Jay , that's a small solid flat tappet for a 482

[chilly460]

When I've worked with convertor companies, basically they want the torque peak RPM as a reference along with all the other vehicle info.  For a race application, more or less they'll try to put the stall at the torque peak.  For street/strip type duty, they'll knock that 500rpm below torque peak.  There are a LOT more variables in place here, but just working ballpark numbers. 

I have no idea what your combo peaked at, but just guessing, I'd say 4200rpm or so?   So, I agree with others, 3500rpm would seem to fit will with your combo. 

[57 lima bean]

"This is strictly a street car and not for drag racing"..........This is all you would need      https://www.summitracing.com/parts/hup-35-25/overview/

 edit note..Measure your crankshaft first.After market cranks may be machined differently.It could be you would need the 1.375 snout on the converter.

[Falcon67]

I would not go 12", 11" minimum 2400+, 10" tight 3000 better.  Your gear/tire size will impact stall on a street car more than anything else - because if you are crusing below stall, that's heat.  A lot of heat.  Put a temp gauge and a deep pan on the trans.  Heat that makes you stop once in a while a let it bleed off.  I know, I use a 4000 in a street car with 4.56 gears and 28" tire.  I can go about 15 miles in mild weather at 3200+ RPM before I need to give the trans a rest.  Thats from dead cold to near 190F.  Slow cruise night, I can last a few miles and maybe 30~40 minutes before parking.  The cooler is large and has a big fan behind it running constantly.  2400 stall, no problems with a decent cooler.  3000 - probably still OK, watch the gauge.  Over that - watch the gauge and the weather.  If you had not said "street", I'd have said 3600~4200, and more gear. 

[jayb]

That's interesting, I've always thought the torque converter adds heat argument was overblown.  I run 6000 stall converters on a variety of cars, including my Mach 1, my Galaxie, and my Shelby clone, and take them on Drag Week where you are driving 200-300 miles per day, in all kinds of traffic conditions.  I never saw a significant rise in trans fluid temperature, 175 to 180 was typical.  My temp sender is in the transmission pan, which of course is not the hottest area, but nevertheless if there was extreme heat somewhere I think I'd have seen it on the gauge.  I always run #6 lines to a good, plate style transmission cooler (like an Earl's), positioned in front of the radiator.

For my part, I would not be afraid to run any stall speed on the street.

[plovett]

To be honest I am not that knowlegable about how stalls, gears, cams and rpm's work mathamatically speaking. I did see a formula that you times the rpm's (lest's say I shift at 6500) by the 25" tire size diameter and then divide that by 336 etc. So what if I went with (on one hand) 373 gears? And on the other hand went with 325 gears, what stall would I use in each case? My aim is not so much of a drag racing car but more of a freeway car. Thanks again for the advice.

In general, a numerically higher rear gear would suggest a higher rpm stall converter.    Not always though.  it depends on your whole combination and the intended use. 

Freeway driving would suggest a lower stall speed, especially with the numerically low rear gear.  A high rpm stall convertor combined with a numerically low rear gear can lead to lots of slippage on the freeway.

Are your rear tires really only 25" tall?  That is pretty short.  The rear tire is essentially the last gear in your driveline.   

If you're serious about freeway driving then I'd go down to a stall convertor in the 2800-3000 rpm range with 3.50 rear gears.  Still want to know your rear tire diameter though.

JMO,

paulie

[e philpott]

I'm with Jay again on trans heat / converter stall  , I never noticed anymore heat in the trans pan when I went to 5000 stall while street driving ....

[james]

To be honest I am not that knowlegable about how stalls, gears, cams and rpm's work mathamatically speaking. I did see a formula that you times the rpm's (lest's say I shift at 6500) by the 25" tire size diameter and then divide that by 336 etc. So what if I went with (on one hand) 373 gears? And on the other hand went with 325 gears, what stall would I use in each case? My aim is not so much of a drag racing car but more of a freeway car. Thanks again for the advice.

In general, a numerically higher rear gear would suggest a higher rpm stall converter.    Not always though.  it depends on your whole combination and the intended use. 

Freeway driving would suggest a lower stall speed, especially with the numerically rear gear.  A high rpm stall convertor combined with a numerically low rear gear can lead to lots of slippage on the freeway.

Are your rear tires really only 25" tall?  That is pretty short.  The rear tire is essentially the last gear in your driveline.   

If you're serious about freeway driving then I'd go down to a stall convertor in the 2800-3000 rpm range with 3.50 rear gears.  Still want to know your rear tire diameter though.

JMO,

paulie

Yes sir, the rear tires are 25" in diameter and I have MT E-streets on her. The following are pictures of the car and the guy who built the engine that is presently in her. 408 stroker. My plan is to put the 408 stroker in a 1966 mercury comet cyclone and put the 427 in the falcon. http://www.badasscars.com/index.cfm/page/ptype=product/product_id=390/category_id=23/mode=prod/prd390.htm  If you read the tech tips on the site there is a question about which gears and converters to use. Thanks!

[plovett]

A 25" tall tire with a 3.50 rear gear is a fairly low (numerically high) overall ratio.  Not ideal for freeway use, in my opinion.    You'll be turning around 2900 rpm at 60 mph, over 3400 rpm at 70 mph, and over 3900 rpm at 80 mph, depending on the torque converter slippage.  That would drive me crazy. 

My Cougar has 4.11 gears with a 27" tire and 3600 stall.  It's not fun on the highway.  If I had 25" tires, I'd need about 3.80 rear gears to keep my overall gear ratio the same.   So your combo is geared higher (numerically lower) than mine, but not by a huge amount. 

paulie