Gale Hawkins
Murray, KY
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Joined: 07/22/2007
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Torque vs. Horsepower Charts for different engines.
Now I understand while pushing past the RPM red line may not physically harm an engine but it is just plain stupid cause it ain't going to do no more cause it has already given all it had to offer. 
The reason we push to the red line is so when we shift the RPM's do not drop so far below the power curve reducing our HP output any more then necessary. Gear Vendor does a good job of giving examples of this fact.
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Flyfisherman128
Broadalbin, NY
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Joined: 08/09/2005
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An engine with hydraulic lifters will not run much more than 5,000 rpm. The lifters can't pump the oil fast enough which makes the lifters calapse and the valves wont open all the way which limits the rpm of the motor. So the max rpm of a stock internal combustion engine is bewteen 4,500 and 4,800. Putting the redline at about 4,200. If you had solid lifters the engine would revup to ten thousand rpm or until the engine came apart. Thats what was explained to me 40 years ago when I was racing.
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Ryles
Woodstock, GA
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Joined: 11/03/2006
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My Miata has hydraulic lifters and redlines at 7500rpm. Pushing it to 7000 is not uncommon and it has 210,000 miles on it.
Now I'm not saying you should push a 454 truck engine to that level. I think 4k is a good number.
Ryles
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LittleBill
Scranton , PA USA
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Joined: 08/29/2003
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push the vehicle to the floor and watch it shift from first to 2nd to 3rd without taking your foot off the floor, watch where it shifts and add 200 rpm to that for the redline, pretty much doesn't matter after that since the tranny is gonna shift anyway
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SCOMP225
Brownsburg,Indiana
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Joined: 12/08/2002
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Gale,
I know there is a lot of good? advise on here with what you trying to accomplish by winding that older big block will lead to # 1 Rod bearing failure # 2 Crankshaft bearing failure Ect. Ect. and sitting in the side of the road with the Rods hanging through your oil pan won't be a pleasant experience.
If your concerned about shift points- Change the Modulator on the Tranny, there is even an adjustable design the raise the RPMs for shift points.
Twisting a stock Big Block beyond 3600 RPM will be fatal in the short term !
Don't listen to all these Bench Racers with the High RPM suggestions !
Chuck
1992 American Eagle
Security: Sam- Black Lab/Glock When He's asleep on the couch.
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Gale Hawkins
Murray, KY
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Joined: 07/22/2007
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Torque vs. Horsepower Charts for different engines.
Clearly from the chart above if not shifting but just pulling a long grade there is really no reason to turn over 3500 RPM in the 454 TBI while when you look at the torque/HP curves of the Ford V-10 6.8L (smaller pistons) you see it can turn up to near 4500 RPM before it starts to drop off in HP output.
I see why the TBI 454 rating at 1600 RPM (385 foot pound of torque) and 3600 RPM (230 HP) were chosen. At any other RPM’s they are less. Assuming the Gear Vendor graph for the TBI 454 (L19) is correct one can see a steep drop off of torque once hitting 3200 RPM so until I see something different I am convinced if one could gear pulling a mountain to keep the engine at 3200 RPM that would be as sweet as it would ever get because you are in theory with a new engine producing about 350 FP of the max torque and only 5 HP short of making max HP. I would think this RPM would burn the least fuel to climb the grade and permit the engine to run as cool as possible. We know if we could force it to 4000 RPM we are not only burning more gas/making heat but have reduced our output of HP some and torque by over 20%.
This is my main reason for wanting a tachometer and then learning how to use that information to get the most of the machine while stressing it the least.
Armed with the tach info and the torque and HP power curves I now see when not to use OD and why it hurts mileage vs. running in 3rd. At 60 MPH I now know in OD (4th) I am turning 2000 RPM (making 160 HP) and in 3rd I am turning 2800 RPM (making 210 HP) and in both cases the torque converter (TC) is locked up greatly reducing transmission temps.
Taking even short rolling grades with the extra 50 HP engine AND the keeping the TC locked or at least locked longer reduces my time to make the grade and with less wear and tear on the machine (both engine and transmission).
A lead foot with a lead damaged brain is not a good combo. I wish I would have started understanding the torque and HP power curves long ago but with a car or pick up tooling around town these are not critical issues unlike towing or carrying you home around like a turtle.
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bill h
el segundo
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Joined: 08/02/2001
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In the above link, the L19 and the L29 charts look pretty similar.
Bill and Susan
84 Barth 30 tag powered by ht502/Thorley, Gear Vendors OD
Siamese Calvin and Airedale Hobbes
4WD Toyota toad
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Bronco4me
Ridgecrest, CA
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I try not to go beyond 3500 RPM on my '92 454. I've twisted it once to 4200 coming downhill on a 6% grade and pulled the tranny into 1st when my brakes got soft.
Bronco
1992 Holiday Rambler Aluma-Lite 33CSXS
2005 Yukon Denali
1990 Bronco XLT Fishin' wagon
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Gale Hawkins
Murray, KY
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Bill I had that thought as well. While they could have been cooking the books I have noticed in my recent research that the GM HP increases were computed at a higher RPM than the 87-95 TBI version of the 454.
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bigfootford
Fair Oaks, California
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Joined: 12/03/2002
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SCOMP255 has my vote!!!!
I've had 2 f250 460's. I run them on the torque curve which peaks around 1800rpm. They would rarely see over 3000rpm. Pulling a hill I see the rpm drop to around 2000 and then it will stay around that rpm fairly easily.
The E4OD tranny torque converter is hard to get locked at times when pulling a hill and it's difficult to determine if it is locked. You have to back off the throttle and then get back on it while watching the tach. If it ain't locked the rpm will vary. The E4OD's gear ratio's really suck.
Jim
94 F-250 ex cab,460, E40D tranny,airbags w/pump,bilstein shocks, 2000 Bigfoot 9.6 2500 camper, Xantrex XADC 60 converter, 1 Universal group 30 AGM and an eu2000i honda genny.
Wife and Molly- Ausie,Queensland healer
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