Delivery Valves - Open Holders
10-21-2009, 05:10 PM
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Delivery Valves - Open Holders
What do you guys know about this modification? Apparantly you can get them as a Mack part and they fit right into the p-pumps, is this correct? If so, does anybody have a part number? Thanks.
10-22-2009, 02:13 PM
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I just ordered a set from Garmon's Diesel, he said with confidence that he wouldn't run them on a daily driver. I'll let you know how they work out!
10-30-2009, 11:09 AM
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How is this going to effect your Opening Pressures? I'd say driveability will be horrible, Laser cuts are so smokey it's all most impossible for a daily driver!
Why not just step up to a bigger injector and tune the pump?
Why not just step up to a bigger injector and tune the pump?
10-30-2009, 01:17 PM
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Not sure on the opening pressure question, but there is only so much fuel you can get out of a little P7100 (160/175hp pumps) So I will try them, if it runs horrible as a daily driver I will only use them when going to have fun!
10-30-2009, 02:51 PM
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If the pump hasnt been benched I seriously doubt your anywhere near the flow that pumps capable of. There's plenty of big power 160/175 Pumps running 191's.
If your not looking into opening pressures with this setup I see problems as soon as you install them!
The key to making power is a properly tuned fuel system, Opening pressures are a key componet in making power!
If your not looking into opening pressures with this setup I see problems as soon as you install them!
The key to making power is a properly tuned fuel system, Opening pressures are a key componet in making power!
10-30-2009, 07:25 PM
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11-03-2009, 07:33 PM
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Okay, Lets start with the fact there's 100's of 160 pumps pushing 600+ RWHP with 191's.
Opening pressures are controlled by the springs & shims in the injector itself for the truck to run correctly, Opening pressures need to be matched to the pump. The injectors stay open for a span that is directly effected by the pop pressures and the pressures the pump is able to provide for a period of time.
Higher Pop pressures require an advance in injection timing due to more pressure required to open the injector which in turn mechanicly retards the timing (sprays fuel later in the combustion cycle), and vice versa with lower opening pressures. Most injector builders opt to stay close to the factory opening pressure, Unless the pumps been modified. Many will disagree but the change in delivery valves changes the dynamics of the fuel system. In most cases not enough to worry about, but in this case with open holders I can see major tuning issues for a daily driver . 181's make ton's of power, 191's are able to flow even more fuel, Most folks actully loose power with Laser Cut's due to way to much fuel! Injector size ,Line size and pump volume,rate of plunger lift, will determine what delivery valve is needed. If the system isnt tuned to drop all fuel pressure out of the line at the end of the cycle, Fuel still enters the cylinder, but at the wrong time.
Guys that are running open holders are using "tuned" fuel systems and have the means to use the fuel and expect fuel system failures!
This is the easiest way I know to explain it in words!
Now, I'll probably come back and edit this so it makes more sense, It's been a long day but Don M (F1 Diesel) Has done the all out best explanation of this exact situation i've seen.
The following was quoted from a Post by Don Morrison
Originally Posted by Soup ****
Good photos. We already know the pump would seize if it was forced to push fuel through that little .025" opening. Not to mention the pressure drop that would occur, even if the thing was able to live long enough to measure it.
Bosch designed the DV holder to operate in two directions. To NOT allow the fuel to return into the delivery valve and plunger area with much force and on the other hand TO allow the fuel to be pushed toward the injector without restriction. This is accomplished by allowing the restriction button to raise up on the outgoing side. It is spring loaded and begins to open around 100 PSI if I remember correctly from 2003.
The area that opens up below the restriction button is plenty large to allow all the fuel a 12mm or a 13mm pump can move with a stock cam pump profile.
The stock DV holder is taller than the open style holder from Bosch because it has to be. This is to allow the spring and button the room it needs to operate.
If you take a small gage screwdriver or similar and a DV holder you can physically push the button up with moderate force. We built an expensive fixture designed to hold the DV holders to flow test them with ISO test fluid 4113 using around 1000 PSI of pressure. This was before we figured out the button was raising up off its seat and the restriction would go away. Turns out the pump and electric motor we used was nowhere near large enough to support 1000 PSI once the button lifted. We were lucky to get 200.
So what happens if the restriction is not there? What if the hole is opened up in the DV holder? It depends on the line size, rack position, RPM, opening pressure of the injector, etc. In many cases on the test bench we found the nozzle would pop open long after the injection event was supposed to have stopped. This would cause fuel to spray directly onto the cylinder wall. Not a good scenerio for a street engine.
Opening pressures are controlled by the springs & shims in the injector itself for the truck to run correctly, Opening pressures need to be matched to the pump. The injectors stay open for a span that is directly effected by the pop pressures and the pressures the pump is able to provide for a period of time.
Higher Pop pressures require an advance in injection timing due to more pressure required to open the injector which in turn mechanicly retards the timing (sprays fuel later in the combustion cycle), and vice versa with lower opening pressures. Most injector builders opt to stay close to the factory opening pressure, Unless the pumps been modified. Many will disagree but the change in delivery valves changes the dynamics of the fuel system. In most cases not enough to worry about, but in this case with open holders I can see major tuning issues for a daily driver . 181's make ton's of power, 191's are able to flow even more fuel, Most folks actully loose power with Laser Cut's due to way to much fuel! Injector size ,Line size and pump volume,rate of plunger lift, will determine what delivery valve is needed. If the system isnt tuned to drop all fuel pressure out of the line at the end of the cycle, Fuel still enters the cylinder, but at the wrong time.
Guys that are running open holders are using "tuned" fuel systems and have the means to use the fuel and expect fuel system failures!
This is the easiest way I know to explain it in words!
Now, I'll probably come back and edit this so it makes more sense, It's been a long day but Don M (F1 Diesel) Has done the all out best explanation of this exact situation i've seen.
The following was quoted from a Post by Don Morrison
Originally Posted by Soup ****
Good photos. We already know the pump would seize if it was forced to push fuel through that little .025" opening. Not to mention the pressure drop that would occur, even if the thing was able to live long enough to measure it.
Bosch designed the DV holder to operate in two directions. To NOT allow the fuel to return into the delivery valve and plunger area with much force and on the other hand TO allow the fuel to be pushed toward the injector without restriction. This is accomplished by allowing the restriction button to raise up on the outgoing side. It is spring loaded and begins to open around 100 PSI if I remember correctly from 2003.
The area that opens up below the restriction button is plenty large to allow all the fuel a 12mm or a 13mm pump can move with a stock cam pump profile.
The stock DV holder is taller than the open style holder from Bosch because it has to be. This is to allow the spring and button the room it needs to operate.
If you take a small gage screwdriver or similar and a DV holder you can physically push the button up with moderate force. We built an expensive fixture designed to hold the DV holders to flow test them with ISO test fluid 4113 using around 1000 PSI of pressure. This was before we figured out the button was raising up off its seat and the restriction would go away. Turns out the pump and electric motor we used was nowhere near large enough to support 1000 PSI once the button lifted. We were lucky to get 200.
So what happens if the restriction is not there? What if the hole is opened up in the DV holder? It depends on the line size, rack position, RPM, opening pressure of the injector, etc. In many cases on the test bench we found the nozzle would pop open long after the injection event was supposed to have stopped. This would cause fuel to spray directly onto the cylinder wall. Not a good scenerio for a street engine.
11-04-2009, 12:57 PM
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There's been alot of discussion on the topic over the past couple of years. My concern for you, is without increased pop pressure, if this mod truly causes the injector to remain open or open after the combustion cycle then ultimatly you'll end up washing cylinder walls and cause scoring.
Are you needing more fuel, or just looking for more? If the heads ringed, I would step up to a slightly bigger set of injectors, and bring in some more timing. I would also look at my current tuning and see if I was missing somthing.
Are you needing more fuel, or just looking for more? If the heads ringed, I would step up to a slightly bigger set of injectors, and bring in some more timing. I would also look at my current tuning and see if I was missing somthing.
11-04-2009, 03:42 PM
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Looking for more fuel, dynamite diesel, pdr and BD have all told me that there is no point in going to a bigger injector because this pump can't flow enough fuel to utilize them. They all claim that 450hp is going to be about the peak I will get from it. Then I saw the article in Diesel Power about jeff Garmon's 160 pump truck putting down 700hp, so I phoned him up and asked how. His explaination was these open holders, 5K GSK, 2095 rack plug and full cut delivery valves. Apparantly that combination will flow 500cc plus, I wanted to try it as an experiment, and not actually run it all for my daily driving. If there is another way to get the 160/175 pumps to flow 450cc plus, I am all ears!! Cheers
11-04-2009, 04:05 PM
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I would send the pump to the pump shop and have it flowed. You could turn the barrels yourself! The mack plug, 181's, 5k GSK kit, Bigger injector, proper timing and fuel delivery and you should be right there! I would play with the open holders just pay attention to any unusual sounds or smells and keep a watch on the oil just in case! The Delivery Valve Holders dont Flow more, they are supposed to "cure" a bottle neck, but many injector builders say there is no bottle neck. I've seen a truck with 181's and 370's break the 480 mark! (At about 20 Deg. timing!)
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