Convertor stall selection

[Heimedw]

Question guys. I'm doing a 512 stroker and running a 727 in a 64 polara. I'm looking at a comp hydrolic roller 252 258 with 571 lift and will be over 600 with 1.6 rockers. I'm going to do a monster trans rebuild kit with shift kit but not sure what stall to get? I have 342 gear and turn about 2500rpm at 60mph but was thinking on going to 3.91 . I have heard a lot about the big cubes eating up cam duration as well....so I was wondering if this is the same with convertor stall. I don't want to run 3500 stall would I be safe with 2500 stall? If you are running a big cam with a auto please share your combo. Ow this is a street car only. Thanks

 

[moes]

If I was you I would contact a reputable converter company like Dynamic or Hughes converters for example. Tell them what your engine build is, how you are going to use the car and have them build one for you setup. It is well worth the money!! Just my 2 cents worth!

 

[66Satellite47]

Be realistic about how the car will be used & call a reputable manufacturer, Dynamic, maybe Coan or Turbo Action. Correct converter selection makes all the difference. Don't "cheap out" on this part.

 

[Lefty71]

Don't "cheap out" on this part.

Agreed, and don't try to pick one off the shelf yourself. Your best bet is get one made for your combo.

 

[Yatzee]

Question guys. I'm doing a 512 stroker and running a 727 in a 64 polara. I'm looking at a comp hydrolic roller 252 258 with 571 lift and will be over 600 with 1.6 rockers. I'm going to do a monster trans rebuild kit with shift kit but not sure what stall to get? I have 342 gear and turn about 2500rpm at 60mph but was thinking on going to 3.91 . I have heard a lot about the big cubes eating up cam duration as well....so I was wondering if this is the same with convertor stall. I don't want to run 3500 stall would I be safe with 2500 stall? If you are running a big cam with a auto please share your combo. Ow this is a street car only. Thanks

I have exactly the same engine with a heavily built transmission and PST recommended 3100 with 2.93 ratio. Couldn't be happier. At 630hp I achieve good hook-up, cool transmission temps and pretty good road mileage.

 

[Heimedw]

So if you have a 3100 stall are you turning 3100rpm on the highway or higher Yatzee?

 

[dvw]

With that cam and cubes it won't need a ton. The trouble is with high rear axle ratio's like you planning the converter is always in slip under heavy load. Get a BIG cooler. PTC makes a nice street/strip converter that is reasonably priced. Call Kenny Ford and ask him. Doug

 

[451Mopar]

Converters have come a long way. I was surprised how tight my 9" Ultimate converter is (good for the street, but does not hit as hard at the track as a loose converter.) Under normal driving does not seem to slip, but it will flash stall to 5,000 rpm. Before I had on older Dynamic 10", 3,200 stall that was good, but not near as tight. Call the converter makers and tell them what you have and want from the converter.

 

[moper]

Get a new convertor. I'd have it custom from Ultimate made up, and keep the stall below your 50mph cruise rpm. Big engines don't need a slippery convertor. Especially if it's a street car.

 

[Heimedw]

Ya that's the thing if I stay with the 342 rear gear and put a 3000 stall in the thing will never lock up on the highway if I put a 2200-2500 stall they say it's not enough for this cam choise. I think I will take the repeated advice and call Dynamic or a big name in convertors.

I was hoping that the big cubes would make up for the low stall because it's still going to make 400lbs at 2500rpm and about 200hp or in that area.

 

[Bighead440]

PTC 9.5" 3000+ stall, that's a healthy hydraulic roller.

 

[68 HEMI GTS]

I run a PTC in my street car. They can build you something for your combo

 

[wyrmrider]

does sound like a big hr which could affect stall speed torque and thus converter solection
what's your compression, heads and head flow, what's the part number or seat timing on your hopefully straw man HR?

 

[Heimedw]

Compression will be just under 10.5, heads will be TF 240 and the cam is a custom grind from 440 sources through comp cams.

 

[wyrmrider]

personally I would not go with 440 source and comp cam unless they spec the lobes from the lobe catalogue for your approval
anyone else out there run 10.5 and TF240 on a 512?
.050 timing is for degreeing cams, not for cam selection

 

[Heimedw]

I have been looking at a lot of 500+ cubic inch wedge engines and the cam sizes. With a cam roughly the size I am looking at (some a little bigger and some smaller) are making max power at around the 5500rpm range. They will carry power over 6000rpm but with this size of cam you wouldn't expect peak numbers at 5500rpm you would think a lot higher. Also these big cube engines are making very impressive numbers at lower rpm. Example a cam rated at 252 258 with 570 lift and a lop of 110 the cam chart would show the power band 3000-6500rpm and the wedge engines are peaking at 5500rpm. So I think the power band ratings should be changed for the big cube engines it should be more like 2500-6000.

 

[moper]

I customer's E body with a B wedge 496 has 3.23s and a 727 with a 2200 convertor. Drives to the track (a little under 2hrs one way), races, and drives home. Runs 118mph, I forget the ET but the 60' sucks with the stock suspension and radials but the potential is there. Engine has 20K miles on it and is driven hard every time he's in it. You don't need a convertor that slips. You will have a lot of torque. So best bet is pay the cash for a very good custom convertor once you decide on the gearing.

 

[wyrmrider]

Dang right Moper run a stock HP converter with that big motor and tall gears and get some data before buying a custom converter- then pay the cash if you need to