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turnin up the hp.


farmallman77

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I hear a bunch of people saying that they turn the screw on their injection pump and increase hp. Im a gas engine guy. Know a ton about em and can fix em good. Ive never ever been around diesels enough to know much about them. So how does turning the screw increase hp? More fuel dumping in????

Chris

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Yep. Followed by to much heat followed by the pistons melting...... :( Seriously, diesels can often be turned up...but ONLY if you know what you are doing and have the right gauges to make sure your engine doesn't self-destruct. (Boost, EGT, etc.) Some engines have a lot of reserve capability in both the mechanical and cooling capacity, and can easily be turned up to produce more power. Others...not so!

Case in point...I have a JD 7410 that has a 6.8L engine set at 120hp. That same motor could easily make 150 or so. Add a turbo and you may be talking even more. BUT....pulling a 20' disk I'm already running the coolant temp right up near the red. Adding HP would probably cause the motor to overheat. So you gotta think of all the parts to the puzzle.

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I hear a bunch of people saying that they turn the screw on their injection pump and increase hp. Im a gas engine guy. Know a ton about em and can fix em good. Ive never ever been around diesels enough to know much about them. So how does turning the screw increase hp? More fuel dumping in????

Chris

Yep, dumps more fuel. Sure you can tear things up but some guys can tear up a sherman tank with a tooth pick. I ran this tractor set at 220hp all summer. Never had to pull the t/a one time raking hay!

bill

image.jpg13_zpshbj8d1x8.jpg

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Diesel fuels control the speed of the engine . Air is unrestricted. Gasoline engine speed is controlled by air. You can set a diesel engine to 500 horses but until you call for them horses you will only be using what is being called for. Therefore you can run without burning it up because you simply are not giving it more fuel than required to do the job. The screws you set are no more than maximum stop screws on a diesel. You can look at the governor inside the pump when engine is running and see that you are not up against that stop until you call for max output. Move the stop screw and governor can move farther until limits of pump of course. On pumps like Roosa master the stop is the leaf spring. It limits how far out the pumping plungers can move and therefore limits the amount of fuel that can be pushed into the plunger cavity. Electronic fuel systems, totally different but amount of fuel still controls the speed of engine.

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Air is restricted in the sense that only so much can be pulled in by say an engine running at 1800 rpm, diesels like to run lean and you can add more fuel but at some point you will only end up with a very rich fuel air mixture and a lot of black smoke. ( unburned fuel) Little additional horsepower will be obtained. So..... a turbo is a great addition to a diesel, you can force that air into the combustion chamber and burn that additional fuel with

efficiency and make more power. Being able to force that added air into an engine is why a 1066 can be turned way up but a 966 without a turbo or any normally aspirated diesel will not go much beyond its rated power. You can add all the fuel you want but if you can't supply the air you won't get the horsepower.

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Here is a very practical example.

I have a 1988 Ford F-250 with a 7.3L naturally aspirated diesel. It was driven with the factory pump setting for 27 years, the last 3, I have had it. It made enough power to get from A to B, and got about 14mpg. It truly struggled to climb grades, especially with a load. It could get to 70mph, but it was struggle. I turned the pump up just a little about two months ago. I also added a pyrometer and eliminated the muffler. It is as if the engine was given a perfect upgrade. It now has power to spare on long grades and gets 19mpg. It is mind boggling how much power this engine had but was being limited. It is recommended that the exhaust gas temperature not get above 1200. With the adjustment I made, I have only been able to get it to 1100 once, and I had my foot on the floor, going up a grade with a load. The point is that the power is there when I need it, but it is doing no harm otherwise. The only "downside" is that more black smoke is produced. I suppose the environment suffers a bit, but I can live with that.

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I hear a bunch of people saying that they turn the screw on their injection pump and increase hp. Im a gas engine guy. Know a ton about em and can fix em good. Ive never ever been around diesels enough to know much about them. So how does turning the screw increase hp? More fuel dumping in????

Chris

Yep, dumps more fuel. Sure you can tear things up but some guys can tear up a sherman tank with a tooth pick. I ran this tractor set at 220hp all summer. Never had to pull the t/a one time raking hay!

bill

image.jpg13_zpshbj8d1x8.jpg

Amen!

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Yep. Followed by to much heat followed by the pistons melting...... :( Seriously, diesels can often be turned up...but ONLY if you know what you are doing and have the right gauges to make sure your engine doesn't self-destruct. (Boost, EGT, etc.) Some engines have a lot of reserve capability in both the mechanical and cooling capacity, and can easily be turned up to produce more power. Others...not so!

Case in point...I have a JD 7410 that has a 6.8L engine set at 120hp. That same motor could easily make 150 or so. Add a turbo and you may be talking even more. BUT....pulling a 20' disk I'm already running the coolant temp right up near the red. Adding HP would probably cause the motor to overheat. So you gotta think of all the parts to the puzzle.

I thought all JD ran hot when you turn up the fuel screw.

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Yep. Followed by to much heat followed by the pistons melting...... :( Seriously, diesels can often be turned up...but ONLY if you know what you are doing and have the right gauges to make sure your engine doesn't self-destruct. (Boost, EGT, etc.) Some engines have a lot of reserve capability in both the mechanical and cooling capacity, and can easily be turned up to produce more power. Others...not so!

Case in point...I have a JD 7410 that has a 6.8L engine set at 120hp. That same motor could easily make 150 or so. Add a turbo and you may be talking even more. BUT....pulling a 20' disk I'm already running the coolant temp right up near the red. Adding HP would probably cause the motor to overheat. So you gotta think of all the parts to the puzzle.

I thought all JD ran hot when you turn up the fuel screw.

The new Deare's may be different, but the old 404's would pop the head gasket if you tried to get more than 110-115%% of stock HP from them for long. Dad's MONEYPIT 4010 lasted about 50 hours set at 100 HP, half the hours idling around cultivating corn.

The pullers that were making BIG HP with the Deare's had to do all kinds of special things to get head gaskets to last. A coat of aluminum paint did NOT make them seal for long.

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