What's the redline?
 

What's the redline of an 84 300 L6?

I've wound them up to 5000, but 4200 seems to the the point where they stop making power.

I've had the pedal all the way down in first and the tach only went to 4200, sometimes only 3900 in other gears

i've taken mine (82 f150) up to 4500 in 2nd (i have a granny low, i only use it for towing) 4000 in third and fourth only goes to about 3700. thats where i can get about the best accelleration

ive heard they fall flat at about 3500 or so depending on gears, engine mods. mine stops around 35-3800...depends on how much lead is in my foot.

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the motor will take 5,000 rpm easily with its 7 main bottem end but the power stops around 3500 and sharply drops off after 3800.

I was angry once because my altenator voltage regulator died and i had to get a jump start cause the battery was dead. when i got'er started i reved it to 5400 RPMs and i didnt go any higher. Its not recomended to do that though.

dadgum 5400? im suprised you didnt sling a rod. ive heard many people talk about the 300's slingin rods at overrevving...

I can't put direct links in yet, because I don't have enough posts. However, using google, typing "building up a six cylinder engine" into the search box and let it search. The 3rd or 4th response should pretty well match the description, and it should be an article from Mustang & Ford magazine. It's a very good read.

It goes into good detail on the Ford inlines, and talks of revving the engines to 7000 RPM.

Awesome article!

"Ultimately, you can achieve 600 hp and 7,000 rpm with a 300ci Ford six."

geez! 600 hp in a 300? ive gotta see that. maybe a future build for mine

i once had my 75 f-100 up to 6,000 once, don't plan to do that again usally the power runs out at 4200 so theres no use having it rev any higher than that unless you have a cam etc.

Thanks guys. Too bad I got rid of that ol truck and replcaed it with an 02 F-150 with a 4.2 6

yeah, I'm not sure the engine is an interference, so there isn't a "hard" red line where the valves hit the pistons and blow the motor. But the 4.9 inline is about the closest thing to a diesel that a gas motor will ever get to so think of it like that with the red lines and power numbers. I have the red line on my tach pointing at 4 grand, and taking it up that far is generally unnecessary. I think that the power is dropping off or already has by then.