safe rpm range?
Freshman User
Joined: Sep 2004
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I have had my modified 300 up to 5000 a few times but there is not really any point since the power falls off around 4500. If I'm giving her wide open I like shift so I catch the next gear around 3000-3200rpm, that seems to really set you back in the seat and usually grabs for a bit of rubber in second.
Postmaster
Joined: May 2004
Posts: 2,854
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Gee, I've gone 170K and never had a problem shifting at 1500 or so, except passing gas pumps more often than most. Idle is at 600. This is a high torque at low rpm engine. 1500 is over twice the speed of idle. It doesn't need to be shifted at higher rpms. I know the feel of lugging and it aint doin' it at 1500.
Senior User
Joined: Sep 2004
Posts: 177
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Yeah, and peak power is around 2000! 
"Not acceptable, Sir!". That stock cam signs off early even under the best of circumstances. I can still putt along at one grand in 4th gear, 3.08 rear and 31" tires (well it is a stripped-down 2WD F150) without lugging it, even with a big single plane intake and a tiny bit of overcarburetion. The deep bass note out the back doesn't break up at all! These things make great rock-crawlers! You can still double the horsepower and have all the low-end torque you need (this is to say the stock figures can stand much improvement more than anything else...).
"Not acceptable, Sir!". That stock cam signs off early even under the best of circumstances. I can still putt along at one grand in 4th gear, 3.08 rear and 31" tires (well it is a stripped-down 2WD F150) without lugging it, even with a big single plane intake and a tiny bit of overcarburetion. The deep bass note out the back doesn't break up at all! These things make great rock-crawlers! You can still double the horsepower and have all the low-end torque you need (this is to say the stock figures can stand much improvement more than anything else...).
Postmaster
Joined: Mar 2002
Posts: 3,545
Likes: 4
From: Coal Region
factory shifting is set at 3800 under WOT. how can ur auto tranny normally shift at 1500? that means ur barley move...come on people, these engines arent made of gold...rev em up a little higher.
Postmaster
Joined: May 2004
Posts: 2,854
Likes: 0
Sorry, I'll keep my revs down low. This puppy's been with me 21 years that way. Think I'll stick with my method.
High revs = More Wear.
Steve
High revs = More Wear.
Steve
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Freshman User
Joined: Sep 2002
Posts: 38
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From: Reno usa
Yes, low RPM seems to be the rule with this engine. I read an article at an inline-6 performance web site (I forget which now) that said that Ford designed and built this engine for industrial use i.e. towing, generators, water pumps etc, sold a bunch for on trailer use. The article said that the engine was designed for a "sustained 3500 RPM for indefinate periods of time".
That said, 5K sounds like risky business for a stock bottom end. I have a mildly built engine, Crane "power truck" cam
a little port matching, EFI exhaust to 3" cat and catback system 
. I haven't ventured into the carb swap yet so it is all limited by intake. I run 4:10 finals and would like a bit more RPM but from the sounds of it I won't get that much for the bucks I would have to spend. I shift at about 2500 most of the time, it will run out to 3k easily but not much past that. 3000rpm at 70 in 4th. I think I will stop messing around and leave it looking sorta stock for the smog guys. What they can't see won't hurt them.
That said, 5K sounds like risky business for a stock bottom end. I have a mildly built engine, Crane "power truck" cam
a little port matching, EFI exhaust to 3" cat and catback system . I haven't ventured into the carb swap yet so it is all limited by intake. I run 4:10 finals and would like a bit more RPM but from the sounds of it I won't get that much for the bucks I would have to spend. I shift at about 2500 most of the time, it will run out to 3k easily but not much past that. 3000rpm at 70 in 4th. I think I will stop messing around and leave it looking sorta stock for the smog guys. What they can't see won't hurt them.
Freshman User
Joined: Sep 2004
Posts: 31
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Well really if you were to take a good look at the bottom end of a 300 and compare to a small block chev or ford V-8 it wouldn't take much to see which one was the most stout. The rods in the 300 are quite a bit heavier and the crank has 7 mains holding it in place. Before I got into these sixes I had a buddy in college who had an '85 4x4 with a stock 4.9 that tried endlessly to punish and blow up in the mud holes even to the point that I remember him actually holding it to the floor in neutral for several seconds a time or two just goofing off while we sat there trying to figure how fast it might be turning. (He didn't have a tach) I would have to guess it was well past five maybe even six, we were probably more lucky that the flywheel didn't come apart!. But despite the abuse, that thing always ran like a clock and never used oil. I think that always stuck in my mind til one day I decided to build one up for my own truck. I certainly don't baby mine now either although I do have a tach and keep a close eye on it. I'm over 100,000 now with no signs of things wearing out.
