cam and converter

Can i use a 3000 stall with a stock engine. I plan on beefing up the engine but i already have the trans out, so i might as well put the converter in now. Will it run ok with a 3000 stall in a stock engine?

 

John,

Since stall speed is determined on more than just the converter, it may actually stall at a lower speed than advertised when used with a stock engine. The actual stall speed may only be in the 2500 range or so. It depends on the torque of the engine, the weight of the vehicle, etc...

You could use it with that engine, but it may not play nice with your gearing. If you're running 2.56 or 2.73 gears, then your car may cruise at an rpm lower than the stall speed.

For example, if you cruise at 60 mph around 2000 rpm, and it stalls around 3000 rpm, there will be a constant condition of "slip" in the converter. When you go up hills, the motor will spool way up in order to pull the hill, then drop back down on the other side.

This slippage builds heat and is no good for the trans. It also will likely decrease any gas mileage you're currently getting. Plus, if your current motor is all done by 5000 rpm, then you've really only got about 2000 rpm of power band between stall speed and your high rpm point.

However, if you're running gears that put you around 3000 rpm at cruising speed, it may not be that big of a deal.

So in a nutshell, you can do it, but it may not be the most efficient thing to do.

 

Steve,
I was just seeing if it would work for a short period of time. We have the trans out to the shop for a rebuild with all new TCI componets. I was thinking of just puting in a 3000 stall while the tranny was out. I plan on doing other upgrades to the engine as far as cam, intake, heads, and didnt want to pull the tranny again after those upgrades where done just to install the verter. And for gears, the car came with a gm 12 bolt with 4.11's in it. I plan on makeing it my track car. Just wanted to see your input on this. thanks.
John

 

John,

If it's got 4.11's, then you should be fine. With those gears and a 26" tall tire, you'll be turning over 3000 rpm at 60 anyhow. And like I said, you may only stall in the 2500 range +/- until you do the modifications.

 

Thanks for the help, should save lots of time.