1999 International 4700 with a DT466E engine

I know this is a tractor site, but I will use this truck to haul my tractors to tractor events, so it's somewhat related. Here's the issue. I recently bought this truck and I'm currently going over it to make it suit my needs. I discovered that the engine was derated at the factory. The RMP is limited to 2100 to meet the original owners requirements. The engine normally runs at 2300 to 2400 RPM. The issue is that the road speed is limited to 60 MPH. So I'd like to get the engine reset. My local Navistar dealer says they can't do it, the factory doesn't support this engine's electronics anymore. I've found software that indicates it can change the parameters of the engine but I'm hesitant to go that route unless someone can verify the software works. I could put a faster rear in the truck, but then I have speedometer issues that can't be fixed because IH doesn't support this trucks computer. I could also add on some electronics that trick the engine, but would prefer to keep it stock. Not looking for HP, just RPM.

Anyone been down this road? Thanks for your replies.

Around here, there are diesel shops that specialize in performance.

They have all the latest aftermarket accessories and tune kits that will do everything from slight improvement to turning the sky black!

Might look around, just because the dealer won't do it doesn't mean it can't be done.

We work on a lot of the Dt466E Engines, but I have not run into your issue. Some of the generic scanners will allow you to make changes, some won't. It is hard for me to believe that the Dealer can't make these changes. There are still a lot of them on the road today. I'd talk to another dealer. One that has a mechanic that has been around a while.

Is it rpm limited or road speed? What rpm if you stay 1 gear down from high? Road speed can be changed, issue may be password. Generally it was limited on road speed.

Where are you located ?

That is what I was going to tell him , plenty of school buses still running that set up. Nothing but about a 20 minute job he just has the wrong dealer or shop.

Why would you want that engine screaming down the road at 2400 rpm. My 98 Ford truck with N 14 Cummins runs about 1500 at 75 mph. What would it entail to change rear ends or add a over drive back box on the tranny.

I'm in south eastern PA

Tires would also speed it up if you wanted to go that route. Also if that is anything like the Speedometer in my Pete there are dip switches in the back of it. You get the tire revolutions per mile and a chart for settings and it can be rest for different tire sizes. This woulds allow you to go to taller tires and set speedometer for them.

It's running 11r22.5 tires now. No switches on eh speedometer, I've had he dash apart for other reasons.

Go here for some good answers from those that BTDT.
School Bus

If it is an automatic, some had 5th gear turned off and there is a complicated but doable procedure to allow fifth gear.

In school buses anyways.

This post was edited by DoubleO7 on 02/15/2022 at 07:19 am.

I doubt it is set at 2100 to meet the original owners requirements.
2100 RPM is a normal setting for a diesel.
The motor is rated at 2200 RPM so they can say it will produce 300 hp.
Does not mean you would want to run it at that speed all the time.
2300-2400 is max it will stand and stay together.

That motor is made for school buses and city delivery trucks; not for over the road and running down the highway at 70 to 75 mph. What are you expecting to get by turning it up 200 rpm to 2300???? 5 or 6 mph. You could do the same 5 mph by switching to 24 inch high profile tires and save the motor.

I suspect the dealer would not turn it up not because they can not but rather they agree with what I just said.

Well not being around the E the old DT 466 in trucks would run up to like 2750 run out and farm tractors like 2650 . Yes the new BIG truck engines turn slower last one i ran was a 3406 E factory set at 550 and ran out at 1850 then a Pittsburgh power box was added for a few more pony's but we kept the RPM's the same as 92 MPH was a little faster then i cared to run . How do i know it would run 92 out on the flats , well ask my boss he took mine for a couple days while i was off and HE got the HIGH SPEED DRIVING AWARD . 85 was as fast as i wanted to go out west while loaded light . I back years ago had the experience of blowing a left ft steering tire at only 60 MPH on a four lane and was Able to keep it up on all 20 wheels . That happened on Rt 11 in Ohio heading south with a 119000 lbs .

] don't know if they slowed the later ones down but I bought a '84 school bus for the 466 in it and it ran at 2900 rpms.

What was this truck originally? What was it used for? It may just be geared low, as someone else here pointed out. Is the speedo accurate? What tranny does it have? Usually almost any truck engine is geared to run about 1500-1800rpm at 60mph, depending on the size of the engine and application. Most all fleet trucks are built and set up run 65mph due to fuel economy. It takes a LOT more fuel to go 70mph. The way the ECM works, is when programed to top speed limit of 60mph, when it 'knows' it is in top gear, you could have the top rpm set to 3000, but it will limit rpm to only allow the engine to go 60mph. I cannot remember about a DT466E, specifically, but there a lot of variables that can be programed into an ECM. It has been a bunch of years since I worked on these, but I actually thought that a Navistar 4700 had dip switches on the back of the speedo head, or the cluster, but you need a manual to program them. If not, the ECM may have tire revolutions per mile set wrong. Your top road speed can be reset, but sometimes these are password protected, usually by the owner. Cruise control top speed can be set separately of the (foot feed) top speed.
But I would not want to run that engine at a constant rpm above 2000 to achieve higher road speed. Mark.

Tractor vet is correct. The DT466 engines in our fleet of line trucks cruised at about 2750-2800 engine RPM, pulling hills, up to about 3000 RPM. Had a CDL evaluator argue with me about it, (We were going through a company mandatory refresher} I had to call the IH dealership, and have the shop foreman confirm it for me, before he would back down. He told me I was over reving the engine. Our mechanics had to be licensed/certified to operate any equipment on the property.