What stall to get?

[chadlovelady]

Have a 85 gmc 3/4 ton 4x4. has new gen vi big block,,6" lift and 36" tires,turbo 400...when i put the truck in gear it wants to die. just wondering what size stall converter i should put in this thing to make it work.


thanks

not sure size of cam or gears...i think they are 456 gears but not sure

[VileZambonie]

So you want to change the converter because the engine is stalling?

[Captkaos]

A stall converter won't help your problems.

[malibu795]

A stall converter won't help your problems.

pending what cam yes it can..

had a 1800 and a 2000 stall behind my 383 with a rpm cam.. one of 2 things would happen.. idle as 850-900rpm with 13-15inHG of vaccum 9 when cold and ambinets is les then 50*
1. stall shortly have put in gear with out throttle
2. pull through the brakes with throttle or riase idle to compensate

i put a 2400stall in it and it behaves like stock pulls idle down about 100-150rpm between netraul and gear vs the 250-300 i saw the the other conveters

but then again timing/idle settings/vaccum leaks can do the same thing as well.

[VileZambonie]

Malibu795, sounds like your engine had other tuning issues. Don't take this the wrong way but do you fully understand what stall speed is? If you do you should know that this isn't what makes your engine stall. The transmission put into gear with foot on the brake would require the ignition timing and idle speed to be the two main factors to consider if the engine is stalling when put into gear assuming there are no other tuning issues.

[malibu795]

Malibu795, sounds like your engine had other tuning issues. Don't take this the wrong way but do you fully understand what stall speed is? If you do you should know that this isn't what makes your engine stall. The transmission put into gear with foot on the brake would require the ignition timing and idle speed to be the two main factors to consider if the engine is stalling when put into gear assuming there are no other tuning issues.

yes sir i am quite awear of what stall speed is and how it is adjusted inside the convertor itself.

the camshaft i am runing is a 234/244* @.050". on a 9.7-10:1 383sbc

anything less then a ~2400 stall convetor (with similar camshaft) will cause either then engine to stall when put in gear or the vehicle try to pull through the brakes. i have run this stall behind a 305 with a 214/224*@.050" cam shaft i did have a 1800-2000 stall orginally behind it.. big diference neather converter cuased stalling issue like i discribed with my 234/244* camshaft

i also have have called  comp, crane, TCI, B&M, Hughes on recomend converter for the said 234/244 cameshaft (all said min 2400-2500 ideally 3000) they told me what would happen(and it did because it did run a lower stall) if i ran a lower stall with that camshaft.

a lower stall ratign will lockup sooner then a higher.. usually the fluid coupling starts 50-75% (pending power band) of the stall rating it starts to go into fluid coupling.. if i am idleing at 800-900rpm.. what will happen if i put a stock to 2000 stall convertor in there? go ahead an hummor me.
with the 2400 stall i have about 750-1000rpm before the convertor starts to go into fluid coupling about 1800-2000 and it is fully locked by 2600rpm

[VileZambonie]

Humor you? Again I was simply asking if you understand stall speed. What is a ratign? I don't understand some of the things you are saying.

the camshaft i am runing is a 234/244* @.050". on a 9.7-10:1 383sbc

anything less then a ~2400 stall convetor (with similar camshaft) will cause either then engine to stall when put in gear or the vehicle try to pull through the brakes.

I'm sure anyone here who has put in a monster cam prior to changing their converter would disagree. Are you running a switch pitch converter with lock up? How are you achieving lock up in your converter? Why would your converter be at the coupling phase at 1800RPM?  The stator is locked under stall conditions so I don't see how that is possible unless your stator is broken in which case you'd have no torque multiplication. I am ATRA certified and know torque converters and automatic transmissions very well. If you would like more information on how torque converters work and what stall speed is I'd be happy to elaborate. Again if there is a stalling issue when the transmission is put into gear you have a tuning issue and it's not the converter. Yes you need to choose the correct converter for your application for optimum performance but it's not responsible for the engine stalling issue.

[Sartobuilt]

What if the converter is bad and ballooning? Eating away at the engine main thrust bearing. I had that happen once. I couldn't get it to idle in gear. It had to idle at 1300 to barely idle at 600 in gear. Everyone I asked said I had a carb/timing issue. Found the problem when I lost oil pressure.

[malibu795]

Humor you? Again I was simply asking if you understand stall speed. What is a ratign? I don't understand some of the things you are saying.

the camshaft i am runing is a 234/244* @.050". on a 9.7-10:1 383sbc

anything less then a ~2400 stall convetor (with similar camshaft) will cause either then engine to stall when put in gear or the vehicle try to pull through the brakes.

I'm sure anyone here who has put in a monster cam prior to changing their converter would disagree. Are you running a switch pitch converter with lock up? How are you achieving lock up in your converter? Why would your converter be at the coupling phase at 1800RPM?  The stator is locked under stall conditions so I don't see how that is possible unless your stator is broken in which case you'd have no torque multiplication. I am ATRA certified and know torque converters and automatic transmissions very well. If you would like more information on how torque converters work and what stall speed is I'd be happy to elaborate. Again if there is a stalling issue when the transmission is put into gear you have a tuning issue and it's not the converter. Yes you need to choose the correct converter for your application for optimum performance but it's not responsible for the engine stalling issue.

the current torque convertor in my truck is a off-the-shelf B&M holeshot 2400 in a TH400 ..i have ran a TCI saturday night special (2000stall) and a sizzler(1800 stall) both did excatly what i said earlier i have also ran this engine with 2 difernt manual transmissions as well.

the best vaccum at idle this engine will do is a 15inHG with 22* of base timing @ 850rpm... camshaft is a Edelbrock RPM with 1.6 rockers. with a 112*LS edelbrock them selves even said that a 2400 stall is min for this cam or you will induce stalling issue.

yes i know the functions of a torque convertor.. i have rebuilt mainy med-heavy duty covnertors.

ratings are usually done with a sepecified tq input. it is the rpm inwhich the driving divice cannot spin any faster. in lamint terms (stalls)

[VileZambonie]

What if the converter is bad and ballooning? Eating away at the engine main thrust bearing. I had that happen once. I couldn't get it to idle in gear. It had to idle at 1300 to barely idle at 600 in gear. Everyone I asked said I had a carb/timing issue. Found the problem when I lost oil pressure.

The original poster's thought here was the engine is stalling due to the stall speed of the converter not due to mechanical failure.

[chadlovelady]

i don't know much about stalls,,,all i know is that with my truck in park it idles very nice,,kinda choppy with the cam ( not sure what the specs are )  then when i put it in gear it wants to die,,if i give it just alittle gas it wants to pull thru the brakes....was wanting to know if a 2500 hughes converter would solve this issue

thanks

[VileZambonie]

Do you have a vacuum advance distributor?

[chadlovelady]

yes i do

[VileZambonie]

Is it hooked to manifold vacuum or ported vacuum?

[chadlovelady]

plugged into front of holly carb