Cam / Torque converter question • The Dodge Challenger Message Board

by **Dale1035** » 15 Sep 2007 14:03

I have a 1973 Challenger with a 340 cid engine. The only modifications to the engine are an Alum. intake, headers and a Mopar Performance 284/484 cam. My question: Will a stock converter work with this cam or will I have to have a stall converter for street operation. I will not be racing the car so I do not want any more stall than I would need for daily driving.
Thanks :?:

by **dave-r** » 15 Sep 2007 16:35

I am thinking that with that cam you would need a 2800 to 3000rpm rated stall speed just to make it drive normal.

However I don't think a 2800 will quite cut it in a small block.
I had the same sized cam in my 440 and the 2800 rated converter was just right. A small block will stall at a lower speed which is why I suspect you might need a looser converter than that.

The cam duration @ .050 is about 241 degrees with that cam so it is on the lumpy side.

You will need 3.55 rear gears for the axle.

Maybe someone that has used the same cam in a small block can comment?

Another thing you can do is call a convertor company and ask them. They advise on these things as it is in their best interest to supply you with the right converter first time.

Also try contacting Graham aka "Transman" on here. I bought one of the converters he uses. I have not tried it yet but I was impressed by the company website. And the service of course. :wink:

by **Dale1035** » 15 Sep 2007 18:18

Thanks Dave
I will talk to some converter specialists before I get a new converter.
The car had what was suppsed to be a 3500 stall in it when I bought it. It was really a pain to get the car off the launching pad. I had the tranny rebuilt and there were no signs of excessive heat in the transmission. However the torque converter had gotten so hot it had turned blue. Therefore I do not know if the converter was bad or if it just had way too much stall. There was no transmission cooler when I got the car, however the previous owner that had traded the car to the person I got it from, said that he had put a cooler on it. If that was the case then the car had been driven very little without a cooler. I would like for the transmission to act as close to original as possible, which is with the least amount of stall and still have the engine idle at stop lights.

by **Jon** » 15 Sep 2007 20:02

Dale, I have the same cam in my 4-speed car. It's not really that rough. Idle is pretty mild IMO. Don't know anything about auto's, so all I can say is it takes a bit of clutching when starting off uphill. (with 323's)

Jon

by **Dale1035** » 16 Sep 2007 2:53

Thanks John
The few times I did get to drive the car I did not think that the idle was very rough and I do have 355 gears in the rear end.

by **dave-r** » 16 Sep 2007 10:35

The more I think about it the more I am sure a 2800-3000rpm stall speed is what you need.
A good cooler is always needed with a higher stall converter. But if you have high gears and never drive over 30mph it is going to be slipping all the time and getting hot.
So the lower the rear gears the better. I would have thought 3.55s would be fine though.

Don't let the trans get any hotter than the engine. 200 degrees max for the trans. 180 degrees all round is ideal.