MrRusty

As the title says... What is the redline for the 4.9L I6? Is there a fuel cut?

blue924.9

well factory tachs went to 6k, but all the tachs did this some people say 5000-4500 but most people say real world 3500-4000 rpm. motor wasnt meant to rev it was meant to work

rancherlee

Factory valve springs don't like anything above 4500rpm but it doesn't make power past 4000 stock anyhow. The short block will handle 6000 with ease

87f-150

On a 87 red line starts at 5600 rpms.

Motorman

With stock valve springs in good shape and stock lifters, you will start to float valves at 4500 - 4800 RPM. The power will start to drop sharply at 3900 RPM.

RLXXI

Start the engine with the vehicle in park/neutral and the parking brake set, hold the accelerator pedal all the way to the floorboard and look at the tach when the engine starts cutting out, the rev limiter will kick in and the tach will tell you what your redline is.

mrgooden

Rev limiter or not, I don't see the use of doing that to an engine.

Just my 2 cents.

Richard

RLXXI

There is no other reason for doing that. It does not harm the engine at all but I must admit the first time I did it, it kind of spooked me. The rpm's climb fast and just when you think it's going to fly apart it levels out and starts surging up and down, limiter kicking in.

Motorman

There is no rev limiter on the inline 300. The only 300 they made with a rev limiter is in the last year of production with the OBD 2 computer and the mas air flow sensor. Either that other poster dose not know that or he thinks it's funny to trick people into blowing their engines.

RLXXI

I figured all Fords have the limiter, every Ford I have ever owned from the early 90's up had it. All that had fuel injection anyway. Even my 90 model Mercury Topaz I4 OBD1 had the limiter, I wonder why Ford would leave that off the I6?