How much hp and torque do large trucks have?

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Patman

Patman

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I'm curious as to how much power is produced by most of the 18 wheelers out there?

I once heard that they only make about 300hp, but put out about 2000 ft lbs of torque.
Is this correct?
 
I cannot tell you specific numbers on this but let me descibe the power in one....

take a 53,000 pound load on a trailer, attached to the tractor loaded with 300 gals of fuel.

Put it in low gear, do not touch the gas, ease out the clutch in idle, and that truck will roll pulling that load.You can pull that load all day in idle and never touch that gas.

You do not touch the gas when first pulling, but once moving, then you accellerate. If you do hit the gas, you run the risk of tearing up a rearend or driveshaft.

Hope that gives you some idea on power/torque on one of these big bad boys.

bob

[ September 30, 2002, 07:13 AM: Message edited by: BOBISTHEOILGUY ]
 
Detroit puts out several models. They are not producing the 2stroke anymore and none of those were used in a tractor trailer rig.

As for the 4stroke engines, detroit has a series 60 model that is very popular in a lot of trucks. Most times it is locked down to 1700 rpms at cruise(65mph) but it will pull a hill loaded like no other. Very powerfull but never have seen one open'd up to 2300 rpms so no idea how it would do at real speeds. Seems to be a good engine.
 
Bob,

When discussed the 2-stroke, Were you referring to the electromotive 2-cycle with the silver
bearings?
 
The detroit 2 stroke has a blower on the side with ported cylinders,sort of like a small 2 cycle.When the piston got below the ports the blower purged the exhaust gases(scavenging I believe it was called)When the piston was on the compression stroke it would pass the ports blocking any more air flow until firing,starting the sequence over,the injectors were driven off the cam.if That was one of my favorite engines to work on when I was in vo-tech 20 years ago,I'm pretty sure the injecters aren't mechanical anymore.
 
RB,

Me too, first diesel I ever worked on when in earlier years worked for Illinois Central. It used a uniflow scavenging process with inlet ports in the cylinder liner and four exhaust valves. Bore was 230.2 mm, stroke was 254 mm, and displacement was 10.57 L per cylinder; rpm was 800 rpm.

PAtman,

For a Cummins turbocharged: six-cylinder, total displacement is 10 L, bore 125 mm, Stroke is 136 mm, CR is 16.3:1, and power output was 200 kW. Compression ratios a little bit higher now.
 
So nobody knows the hp/torque that they put out?
frown.gif
 
Engine ID HP Torque at Rated RPM

ISX 500 ST 500 1650/1850 @ 1200

ISX 475 ST 475 1650/1850 @ 1200

These engines have the EGR valves but actually produce an extra
200 lbft of torque.
 
quote:
Originally posted by MolaKule:
Bob,

When discussed the 2-stroke, Were you referring to the electromotive 2-cycle with the silver
bearings?
Click to expand...
GMC/Detroit Diesel used to produce a lot of small and medium sized 2-stroke diesel engines. The 6-71 was probably the best know--inline six and 71 cubic inches per cylinder. They had 8V-71, 12V-71, 4-71, 3-71, 2-71 (used on the reefer machinery on reefer railroad cars). They also had the -53 series engines and -92 series, probably others. I remember getting gas in a truck stop in Nevada years ago, and a guy went by in a pickup truck that sure sounded like it had a 4-53 in it.

Now Detroit Diesel is owned by Daimler-Chysler, includes the fine line of German MTU engines, and also some engines produced in Italy and Brazil. No more two strokers.

The two stroke uniflow power cycle was:
--Power: Piston near top-dead-center, injector sprays in fuel, piston is forced down due to the fuel comustion.
--Exhaust: Piston still moving down, exhaust valve(s) in head opens.
--Scavenge: Piston passes ports in the cylinder side, pressurized air flows in and blows exhaust out the exhaust valve.
--Intake: Exhaust valve closed, blower pressurizes cylinder with fresh air charge. Piston passes bottom-dead-center.
--Compression: Piston closes off intake ports as it moves upward.
Power: ditto above. All this happened on one revolution.

Two-stroke engines must have some sort of an air pump. Jimmies all had a supercharger, and some also had a turbocharger. Large 2-stroke engines have turbochargers and electric blowers to supply the air charge for starting and low load. Very small 2-strokers (outboards, etc.) use the bottom of the piston as an air pump.

Ken
 
Ken,

I was referring to GM Electromotive V12 and V20's which used a Roots Blower. The air inlet ports at the bottom of each cylinder liner are uncovered by the descending piston, and the scavenging air flows upward along the cylinder axis.
 
I had a chance to see those engines at the Electromotive plant a few years back. It was for a 75 year anniversary open house. It's amazing how huge the engines were.

Everything we were shown and was talked about were turbos and not superchargers on the engines. MolaKule, are you aware of Electromotive still using superchargers on those diesels or was that in the past?

Another interesting thing was any open engines in the process of being assembled had a huge fan blowing on them as they sat over the week-end. The fans looked like those 1930s style fans except they were about 6 feet in diameter
shocked.gif


The huge three phase alternators that were about 6 feet in daimeter were something to see too. I don't know if everyone realizes, but the diesel engines spewing their soot as they chug along, aren't driving the wheels but powering that alternator in order to provide the energy for electric motors to drive the wheels.
 
"Everything we were shown and was talked about were turbos and not superchargers on the engines. MolaKule, are you aware of Electromotive still using superchargers on those diesels or was that in the past?"

This was circa 1975.

The Electromotive Railroad "engines" were indirect drives, I.E., diesel engines turned alternators and dc generators, and electric "traction" motors actually provided power to the wheels. A series of relays and resistors reduced power to the traction motors to control torque and speed. The relays, lights , and radio communications were powered by a 64 Volt DC generator. In the earlier days, 500 Volt 500 Amp DC generators powered the traction motors; glad to hear they switched to three-phase AC; that method is more efficient.
 
I drove a 93 Freightliner for a couple years. It had a 60 series Detroit. The engines was refered to as a 350 Detroit because it was rated at 350HP. However, if the cruise was engaged, it would actually push it up to 365HP. You could actually hear the engine 'trying harder' if you were driving up a hill without the cruise, realized you were losing speed, and quickly hit 'set'. I have no idea how much torque it put out, but Bob is right. You could pull a house off its foundation without breaking a sweat. The 60 series was (still is, I'm sure) a very electronicly controlled engine. I actually got 8 MPG in the summer with a 53' trailer (as long as I left the cruise at 55).
 
The Detroit Diesel Series 60 now makes up to 500hp. and I think close to 1500 pounds of torque. The one in my truck makes 430hp. Displacement is 12.7 litres. It can pull mountains almost as well loaded as empty. They have come a long way with diesels over the years. Mine averages a little over 6 mpg., which is pretty good, considering how much weight you're pulling.
 
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