oarwhat
Senior Member
Couldn't you just turn up the aneroid setting? Many years ago I had Macks that took forever to get to highway speed. there just wasn't enough boost to trigger the pump to send more fuel. The fix back then was just disable it.
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NTC 400
- Thread starter Rod78
- Start date
Well I just loaded up at my east farm and brought the grain home (12 miles). Very happy with how the stock engine performed. There isn't a nasty headwind today though. I also changed my shift rpm. I used to shift at about 2000. Today I ran to the high idle limit ( 2250ish). That made a huge difference on the next gear's power. Is 2250 too high to run the rpm? And I did some math and indont have 3.55 gears. I have 3.90s. I get to haul 90 miles over the mountain tomorrow. I think it'll do just fine.
Truck Shop
Senior Member
IMO 2250 is a bit high 2150 is a bit more in scope. The only fuel psi gauges that don't bounce are the high dollar liquid filled type. At least that's what I have found. And good on the 3.90 ratio.
Well I got to use the truck. Made 7 loads in the last 3 days. The first 4 loads were without much wind and the truck performed very well. Was able to get up to 58mph and hold it there on the flat stretches quite easily. The hills, well I was down to 35mph making it work but it did what I asked. Those 2 days the truck averaged just over 5mpg. Yesterday there was a 35mph headwind and I couldn't hold 14th gear on the flats. Down in 13th doing 45-50mph. The hills I was only down a couple mph when I created them. The 90 mile trip took me an extra 10 minutes. No big deal. What surprised me though was when I fuelled up after 3 trips yesterday I was still just over 5mpg!! Weird.
Well I got my pyrometer installed sunday and took 2 more loads across the mountain. As hard as I could lug the truck I was showing about 800 on the cool side of the turbo. Flat out hard working with good truck rpm I would only get to 700F. So I'm very happy with that. I'd say there is room to add a bit more fuel safely. Don't you?
Truck Shop
Senior Member
You could add some fuel, get it up around 900 to 950. Proper temp for fast roasting a chicken.
I just spent 8 hrs in my pickup truck driving today thinking about the western star. When I get a couple spare hrs I might just swap the fuel pump out for the 475 pump. I have all the working gauges now to not melt it down. If I pay close attention to the gauges what could it hurt??
Truck Shop
Senior Member
Remember no side stepping it.
mekanik
Senior Member
The 475 injectors will NOT work with the 400 cam!
The 475 injector has .266" stroke the 40 injector has .228" stroke.
Terry
The 475 injector has .266" stroke the 40 injector has .228" stroke.
Terry
Truck Shop
Senior Member
Yes you are totally correct, 475 injectors with .266 stroke were MVT cams only. The CPL 676 BCIV had a higher lift cam but only on the exhaust.
Truck Shop
Senior Member
Now after searching through four boxes of engine notes and odds and ends off and on for the last week I finally found what I was looking for. Below is a data plate I removed from a BCIII
Full Flow Cooled engine that was run out of oil some years back. It's a factory Cummins BCIII rated at 450 HP @ 2100 RPM CPL #1193 Built in 1995. The tag is easy to read, here is your
factory ticket for custom rated HP by Cummins in a BCIII. Although I see photo went sideways. These engines were rare birds.
Full Flow Cooled engine that was run out of oil some years back. It's a factory Cummins BCIII rated at 450 HP @ 2100 RPM CPL #1193 Built in 1995. The tag is easy to read, here is your
factory ticket for custom rated HP by Cummins in a BCIII. Although I see photo went sideways. These engines were rare birds.
mekanik
Senior Member
I was the Cummins guy in a truck dealership from 1980 till 2004.
I only ever saw one and it was in an American grapple yarder.
The 475 and the 450 both used the high efficiency Air Research aftercooler.
I only ever saw one and it was in an American grapple yarder.
The 475 and the 450 both used the high efficiency Air Research aftercooler.
Truck Shop
Senior Member
And he has the 475 after cooler in his 475 parts pile. And this one the tag belongs to was used in a tub grinder.
Getting back to the 475TT. Could I build this with fixed time camshaft instead of the mvt and not smoke too much. Having trouble sourcing mvt parts. So everthing with cpl matching except the mvt. If so, what would I time the injectors at?
Truck Shop
Senior Member
if you go to Cummins they can look up the timing code GU on that data plate that corresponds with the CPL of 1193. I saw that 450 run cold and hot and it never really smoked as bad cold as some other big cams.
Truck Shop
Senior Member
If you look on the Cummins data plate above it says {T.S. Zero Lash=Top Stop injectors} No it's not STC. It's a fixed time BCIII