I have a 94 F150 with the 4.9 inline 6. Any one know what the maximum safe RPM for this engine is? Also, any one have the horsepower rating?
Thanks

 

160hp(at 3400rpm) and 260-265ft-lbs(at 2000rpm). I had my 95 spin at 5500, which is where the fuel shuts off, but i wouldn't take it above 4500 to be safe. It is not a fast spinning engine and makes no power above 3500-3600rpm anyway.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Sunroof, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Then theres:
99' Mustang GT 4.6L
88' F-250 Superduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Top speed is 65mph, Go Baby Go!

 

Yeah, the 4.9 does not like going much above 4500, but i had a friend that had one (HD variety) in his tractor and would run it all day at 5000rpm, it's a tough engine, but it powers best in the low rpm ranges anyways.

-Necro

 

>Yeah, the 4.9 does not like going much above 4500, but i had
>a friend that had one (HD variety) in his tractor and would
>run it all day at 5000rpm, it's a tough engine, but it
>powers best in the low rpm ranges anyways.
>
>-Necro

Now you got me curious. I knew the 300 was put in a few tractors, but nothing specific. What kind of tractor was this? Anybody know of any other tractors that used the 300?

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[font color="green"]1995 F-150 Supercab XLT 4x4 302 M5OD 8' bed [/font]31x10.50's
[font color="green"]1986 F-150 4x4 300 I6 NP435 [/font]Warn hubs, DeeZee bed caps, '96 XLT bench seat, new paint job

 

There are two kinds of 300s. The ones that went in trucks (light duty) and the industrial engine (heavy duty). The HD had forged pistons, crank, and was very strong. Production ended in 2000 while they stopped in trucks in 96, and maybe some 97 F-250s. A few of the HD six's made it into trucks but not many. Theres no outside visual difference. The HD six was used in tractors, chippers, and even cranes. There is a boat crane that lowers boats into the harbor near here that has a 300/6. They were also used in sidewalk plows and things like that.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Sunroof, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Then theres:
99' Mustang GT 4.6L
88' F-250 Superduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Top speed is 65mph, Go Baby Go!

 

My charts show the 300 I6 (1994) has 145 to 150 hp at 3400. I think 145/265 was for the 3.08 and 2.73 rear ends. I believe in the late 60s and the 70s the HD 300 was in a lot of trucks and busses, even UPS trucks. I ran a chipper that had one. Even heard that it was installed in some combine harvesters. Also pretty sure the HD 300 was optional in the pickup truck at one time. I don't rev mine past 4000 and usually not past 3600. I consider redline to be 4000, though I am curious what redline Ford puts, if anybody has an older truck with the 300 and a tach that shows the redline (late model tachs are all 6000 and have no redline). Someone with a 300 and an automatic posted that floored it shifted somewhere around 3600 or 3800. An automatic when floored should shift slightly below redline. Pitt Electric used to sell these 300s for generators and their spec said the max sustained rpm was somewhere around 3400 (I will look up in my files if anybody is interested). This would be for hours of steady operation, whereas a quick shot to 4500 may not be a problem (don't know though, as I haven't done it). As one post said, not much power after the mid to high 3000s, so there is nothing to be gained in reving higher than 3800 to 4000.

INLINE SIX POWER!
300 Cubic Inches of Low RPM Truck Torque! And twin-I-beams too!
"Drive a stick young man! There'll be time for automatics when you're old and unable."

 

Usually the automatic will shift slightly before the redline but not in the six's case, it doesn't have the high-end power so it shifts right after the max in the powerband. My 95 spun 5500 so i'm sure the redline starts at 5 and stopped at 5500. the rev limiter is set at around 5500. I also forgot to mention that, yes the 300s were used in UPS trucks and also fed ex trucks. My uncle worked as a mechanic for fedex.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Sunroof, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Then theres:
99' Mustang GT 4.6L
88' F-250 Superduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Top speed is 65mph, Go Baby Go!

 

 

What about a 351/W?

When i gun the sucker from a Dead stop in about 5 Seconds i can be at 4500 and then they drop to about 1500 or so, Theres not a day when i dont hit 3000-3500 at least 20 Times (Stop & Go) Is this safe for my Engine? I know i love the way people from Miles look because its got to be the loudest Friggin ford on the block (Post '79)

Thanks

 

>What about a 351/W?
>
>When i gun the sucker from a Dead stop in about 5 Seconds i
>can be at 4500 and then they drop to about 1500 or so,
>Theres not a day when i dont hit 3000-3500 at least 20 Times
>(Stop & Go) Is this safe for my Engine? I know i love the
>way people from Miles look because its got to be the loudest
>Friggin ford on the block (Post '79)


If your 1-2 shift drops from 4500 to 1500, you have a super wide ratio tranny. But for real, that kind of drop sounds like a 1-3 shift. Is your second gear blown? Typical basic automatic would be three speed (plus OD). First three gears would be 2.50, 1.50 and 1.00, so the 1-2 shift coming off 1 at 4500 should drop it to about 2700 rpm. Don't know what the factory rated hp peak is on 351 but you should be OK revving to a few hundred past that. 4500 doesn't sound all that high for a V8, though a 351 is a stroker and my 460 V8 motorhome flat out will shift (auto tranny) at 4100.

 

Yeah there has to be something wrong with that, shifting at 4500 is ok if it's punched but it shouldn't drop that low. I think tallpaul is right that it's skipping 2nd gear. Seems like it atleast. Try putting it in first, than getting up to 4500 and shift into second manually and see where the rpms go.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster American Thunder Exhaust, Sunroof, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Then theres:
99' Mustang GT 4.6L
88' F-250 Superduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Top speed is 65mph, Go Baby Go!

 

Thanks,

I didnt know you could shift from 1st To 2nd w/o Stopping... Wont it break something? It is an Auto so you mean Put it in 1st and start driving then Pop it into 2nd?

The Engine has only reved up to 4500rpm 3 Times since ive owned the Truck, I put a Highflow 2 into 1 Cat and a Stright pipe and it rev's alot quicker than w/ The stock setup. I know it drops down from 4500 to 1500-2000 Depending on the incline.

Thanks

 

How are you driving it? Do you floor it to 4500 and then let off the pedal? That will put it from first to third and is properly functioning, because by lifting off from the pedal you have eliminated the demand for acceleration and the tranny responds with the highest suitable gear for the road speed. But if you floor it and hold it floored it will shift into second before third. Yes you can manually shift the auto tranny, but be careful not to pull the lever too far and blow reverse. I manually shifted my motorhome in the mountains quite a bit.

BTW: Depending on the tranny 2 is 2 on some (my E4OD motorhome) and in 2 will start in 2 from a dead stop; but on others you put it in 2 and from a stop it will run a 1-2 shift (Wife's '92 Aerostar). Your owner's manual should tell you which yours does.

 

my 351 does the exact same thing, i had the ford dealership check it out and they said that its just geared to pull and for speed. he also said the pedal is fun to push. mine is loud too i love it. but neways there is nothing to worry about, the engine can handle those high rpms easily

 

Yeah! My pedal is fun to push too