Sedanman
67-9 Valiant specialist
What stall would be good for a cam power range of 1800-5500 rpm? This will be a daily driver car. It is a balanced 340 motor in a 2800 lb 67 Plymouth Valiant. Thanks for any input
Choosing stall speed for daily driver
- Thread starter Sedanman
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Sedanman
67-9 Valiant specialist
Sedanman
67-9 Valiant specialist
Also a recommended rear gear size since I can't locate any info on what they consider a higher gear on their site. I'm also using 255/60/15 tires
nqkjw
Well-Known Member
Std stall will be OK with that cam or one of the basic 2500 convertors will liven it a bit more.
Good all rounder ratio with those tyres is 3.7
Good all rounder ratio with those tyres is 3.7
Call whatever converter manufacturer you plan on using, give the your specs and tell them what you plan on doing with the car. They will have some suggestions for you.
Cam card lists 1800 to 5500 rpm operation range, stock 2000 converter rpm, and 9:1 compression. Gearing has to be calculated based on your tire diameter, and average speeds you will be driving the car most of the time.
I wouldn’t set the car to drag race if you are going to drive a lot on the interstate where engine will be developing high rpm at normal highway speeds.
I wouldn’t put a tall highway gear (2.7 or taller) in it if all driving is in town below 45 mph. It will be a turd on takeoff, and running at or below 1800 rpm is out of cam’s range. That means no torque, crappy fuel economy, and carburetor tuning problems due to low vacuum below 1800 rpm.
I can tell you that listening to an engine cranked up to 3000 rpm or more at 60 mph for anything but a short trip is annoying and not particularly fuel efficient. Figure out where your torque curve is and design cruise rpm based on that curve.
As for a converter, you want that thing stalled as soon as possible to reduce transmission heat, and boost fuel economy.
As someone advised above, call a converter company with the cam specks, and anticipated driving conditions, proposed rear gear, and see what they say.
I wouldn’t set the car to drag race if you are going to drive a lot on the interstate where engine will be developing high rpm at normal highway speeds.
I wouldn’t put a tall highway gear (2.7 or taller) in it if all driving is in town below 45 mph. It will be a turd on takeoff, and running at or below 1800 rpm is out of cam’s range. That means no torque, crappy fuel economy, and carburetor tuning problems due to low vacuum below 1800 rpm.
I can tell you that listening to an engine cranked up to 3000 rpm or more at 60 mph for anything but a short trip is annoying and not particularly fuel efficient. Figure out where your torque curve is and design cruise rpm based on that curve.
As for a converter, you want that thing stalled as soon as possible to reduce transmission heat, and boost fuel economy.
As someone advised above, call a converter company with the cam specks, and anticipated driving conditions, proposed rear gear, and see what they say.
C130 Chief
Mechanical Genius
A stock "high stall" Mopar converter should do you fine if you're primarily street driving. Your cam is pretty darn close to the OEM 340 cam, so a converter close to the 340 piece would make sense. Gears wise, 3.23 - 3.91 depending on how important 80 MPH freeway cruising is. 3.55's are a good compromise.
Sedanman
67-9 Valiant specialist
Thank for the info. I did notice a few converter companies can't give an exact stall range & it seems to vary depending on your engine. This is also a cast crank 340 that had the lower end balanced & cam degreed. Do I get the converter for the cast crank 340 or for a neutral balanced 340? What was the factory stall?
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