Community Forums

donandmax · 09-08-2011, 02:41 PM

I have a 1996 Ford F 53 chassis with a 460 V-8. When climbing long grades in co. at high altitudes Iam using 2 nd gear at 3500 rpm. I read on this forum that people with the V-10 use 2nd gear @ 4000 rpm. Should I up it to 4000 ?

Mekanic · 09-08-2011, 03:08 PM

unless you REALLY need to climb faster I see no need to crank it up higher.
Are you wanting to use more fuel per mile? the v 10 is a smaller engine than your and it is tuned for the higher RPM

Always-RVing · 09-08-2011, 03:12 PM

Check out the Thread: What RPM do you climb with on V10?

http://www.irv2.com/forums/f23/what-...tml#post952794

donandmax · 09-08-2011, 03:15 PM

Quote:

Originally Posted by Mekanic

unless you REALLY need to climb faster I see no need to crank it up higher.
Are you wanting to use more fuel per mile? the v 10 is a smaller engine than your and it is tuned for the higher RPM

Do you know what rpm the 460 is redlined at. ?
Thanks
Don

Mike Canter · 09-08-2011, 03:57 PM

Being a Ford type of racing guy I believe you will find out that motor made max torque of 400 ft lbs at 2200 rpm and max hp of 245 at 4000 rpm. Climbing steep grades requires HP and not torque. So if you are at 3500 rpm you are below the peak HP and you should come up on the rpm to 3900-4000 if you feel comfortable with that. If you are too low in rpm and something or another car gets in front and you slow down then you will have a hard time recovering speed. There is really no such thing as great gas milage if climbing a steep grade. Also if you drop the rpm down too low and lug it will want to overheat. The best thing is to select a gear for a mph that you feel comfortable with the engine at 3900-4000. With my 46,000 lb MH with the big diesel that makes max power at 1800 rpm on a 6% grade I usually climb it at 1800 rpm at 48 mph which is 4th gear. If it is over 100* outside or high altitude or a 7% grade I sometimes have to drop to third gear at 1800 rpm which is around 35 mph. Boy does that feel slow. My coolant temp gauge is a real good indicator if all is correct.

Gary RVRoamer · 09-09-2011, 09:19 AM

I had a 96 Southwind 460 with a Banks package. It would run at 3500 RPMs comfortable (if noisily) and I could push it to 4000 if I wanted a bit more power (Mike Canter is right-on on the RPM values). I seldom ran it that high because of the noise and it only made a couple mph difference anyway.

donandmax · 09-09-2011, 09:44 AM

Gary and Mike... I think you answered my question.. Thanks and
Happy Motoring
Don

Always-RVing · 09-09-2011, 09:45 AM

Yep,,,, You'll know what she'll do by running at the max output at the optimum RPM and watch the water temp as mentioned.

donandmax · 09-09-2011, 09:49 AM

One more question... Is there any difference between the 1996 460 that they put in a p/u truck and one they put in a moho ? seems I read "HD" for the moho someplace. If that is so what makes it HD..

Mike Canter · 09-09-2011, 01:47 PM

A guess would be stronger connecting rods and maybe forged pistons or a forged crank vice a cast crank or all the above.

You might try asking on this forum
460 Ford Forum

Clay L · 09-09-2011, 03:58 PM

Quote:

Originally Posted by Mike Canter

Climbing steep grades requires HP and not torque..

Then why can a 300 hp DP pass me with ease going up a grade when I have 340 hp?

Mike Canter · 09-09-2011, 04:16 PM

Clay, providing your motor is running correctly and you are at the correct RPM then what makes the difference is horsepower to weight ratio which includes what you are towing. Do you climb steep grades at or close to the RPM your engine produces max HP. Do you know what that RPM is?

Also, the rated HP of an engine is a little misleading especially when comparing two different engines. The RPM at which HP occures and torque dictate the engines performance.

Clay L · 09-10-2011, 11:38 AM

This is a graph of the torque and HP for my engine. I usually let the Allison and engine computers decide the uphill gear choice for me.

What I see out there in the real world is that I can get from zero to 60 mph faster than a lot of diesel pushers with 300/330 HP but with their higher torque they can hold their speed (or even increase it) on grades where I will lose speed.