Redline for stock 401??

[CJ-7-401]

I've got a "stock" 401 out of a 1978 Jeep. What is a safe redline RPM??

A) 5000
B) 5500
C) 5800
D) 6000
E) None of the above. It's ______ .

[jeep_man_401]

I have a basically stock 360 that I've turned 6000 all the time. Stock valve train, cast pistons and a bigger cam. I would think a 401 can handle 6000. Maybe more until the valve's float.(Forged rods & crank are standard on 401's)

But why? A stock 401 will make the power down low...there is no real reason to turn it that high, unless you modify it to make the power up there. Better intake, clean up the ports, headers. etc.

Funny, this summer the guy's at the college put a brick on the gas peddle of a 3.1PFI V6 and it ran until it got hot enough to start the car on fire. 111!!! Melted the rear bumper from the heat under the car even!

[jeepsr4ever]

I would base your stock redline on valve float :?: In all seriousness you dont want to push much past 5500rpm in a stock application.

[CJ-7-401]

It might be a dumb question... but how do you know if your valves are floating??? What does it sound and feel like?? What are the beginning signs of this as your rpms get over 5K??

And yes I agree the power / torque is down low from 2000 - 4200 rpms, But curious about the "redline" though.

[Goose]

The engine will start to miss and pop through the carb.. this is also a great way to test the valve springs and keepers.. if a keeper lets go or a spring breaks it will suck that valve and turn the rest of the engine into scrap..