Torque Convertor Issue/Question

[camaro1969]

I have a rebuilt 350 engine, all new parts, probably will be pushing around 325hp. I put my stock convertor in that comes with the th350, was told a stock convertor is around 900-1200 stall.. so what im scared is, will this convertor be good for me, or should i be buying a torque convertor with a higher stall? 3000-3500?

what im scared is something will break down when i hit the pedal...

what should i do? or should i not be worried?

[GregWeld]

Vic --

Good question -- which needs to have more information before anyone could respond properly.

Cam - Rear gearing - tire size all play an important role in converter stall speed. So can you provide this info?

On the surface - and 325 hp 350 isn't very radical - in fact is almost dead stock... so unless there is more to the story - the stock converter would be fine... but let's see what else you've done - or are planning on doing before you commit.

[camaro1969]

Originally Posted by GregWeld

Vic --

Good question -- which needs to have more information before anyone could respond properly.

Cam - Rear gearing - tire size all play an important role in converter stall speed. So can you provide this info?

On the surface - and 325 hp 350 isn't very radical - in fact is almost dead stock... so unless there is more to the story - the stock converter would be fine... but let's see what else you've done - or are planning on doing before you commit.

242 compcam, 12 bolt rear 3.07 gears, 15 inch bfgoodrich t/a radials...

every engine spec.

1479H keith black pistons .30
139 piston rings
CLE-CB663P rod bearings
CLE-MS909P main bearings
CCA-817-16 compcam lifters
SLP-260-1000 gasket kit
CCA-981-16 compcam valve springs
CCA-1412-16 compcam roller rocker
ARP-134-6003 arp connecting rod bolt

let me know what else you need to know

[Autokraft]

What about Intake, Cylinder heads, carb, headers?

[camaro1969]

Originally Posted by Autokraft

What about Intake, Cylinder heads, carb, headers?

edelbrock intake, steel factory gm heads, 670 CFM holley carb, 2451 non ceramic hooker headers

[Autokraft]

Vic, you can try your stock converter and see how you like it but my guess would be sooner or later you are going to want to step it up performance wise. A little more stall can turn it into a tire fryer

[GregWeld]

Vic --

The more torque you make the higher the stall speed of any converter... the RPM "reference" is just that... it's a value used to rate one stall speed against another. What the higher stall converter will do is to allow the engine to 'rev' freer / higher - before the converter starts to make the power transfer... doing this also creates higher heat in the fluid (transmission)... and it causes "slip" at cruising speeds... That's why modern overdrives use a "LOCK UP" converter. They have a clutch like system which 'locks up' and makes the automatic transmission more like a stick - direct drive so to speak. But you're running a TH350 so that doesn't count.

Higher stall speeds - lets say a 2500 stall rated converter would allow a motor to idle easier (it's not fighting the torque converter) so is handy if you're motor is struggling to idle... it would "feel" a little sportier as you'd have to give it a bit more throttle to get things moving...

Your motor is not that 'radical' - so I wouldn't go beyond a 2400 stall - and I'd probably be more inclined to go with a 2200 stall.

Perhaps others will chime in here and have additional information for you.

[thedude327]

Originally Posted by camaro1969

242 compcam

Just curious , but is that 242 duration @ .050 lift or is it advertised(total)duration? Could you also give the lift specs? If your running , comp cams XR294HR, which has 242 duration @ .050 and .540/.562 lift then not only will you need a higher stall converter, minimum 2400 , but you also are going to need to change your rear axle ratio over to 3.73:1 or it will have no low end on the street.


Paul

[6D9]

Originally Posted by thedude327

Just curious , but is that 242 duration @ .050 lift or is it advertised(total)duration? Could you also give the lift specs? If your running , comp cams XR294HR, which has 242 duration @ .050 and .540/.562 lift then not only will you need a higher stall converter, minimum 2400 , but you also are going to need to change your rear axle ratio over to 3.73:1 or it will have no low end on the street.


Paul

X2

Even with a 2400 converter the car is gonna be a dog with a XR294HR. What is the part # or grind number on the cam??

[GregWeld]

Think that is a Comp Cam GRIND number XR 294 HR -- From their Extreme Energy line - 294 Hydraulic Rollers... PART NUMBER 12-443-8


THAT is one big ass cam... probably starts to make some power at 2800 rpms...

You guys are right - in a small block - that will suck on the street....

I'm running the XR288HR in my 427 ci small block - with 8 stack efi... the cubic inches can "eat more cam" and the lack of reversion in the 8 stack efi intake also helps tame the cam as well.... and I'm running a 2800 stall converter with 3:73's