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Are the electronics in a QSB4.5 mandatory for the engine to run? Is there a way to get good performance out of one without the electronics?
 

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The electronics fire the injectors. How else do you plan to get it to run? Mechanical conversion?
 

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Yeah look into a 24 valve p-pump convserion parts list. You will likely be able to use much of the 24 valve plates and mounting stuff and the run the B3.9 pump and lines.
 

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Question would be which QSB 4.5? Is it the 16 valve or 8 valve. If it's the 16 valve, they are common rails. That would take a lot of custom parts to make it happen. There are kits to put a P pump on Dodge common rails, however, I believe the 4.5's are rear gear train and that makes it very complicated. I have seen a VE pump set up for rear gear train, so in theory it could be done. The 8 valve would be much easier. It is identical to the 3.9 except a longer stroke. There, it would be just changing the front housing, pump, and related parts.
 

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Are the electronics in a QSB4.5 mandatory for the engine to run? Is there a way to get good performance out of one without the electronics?
No, I just got four 4.5l long blocks that were mechanical. All worn out. 8 valve heads. I'm gonna rebuild one or two of them. All of them are front gear trains. Injectors from 98.5 to 2001 24 valves would work for a 16 valve head. Mine are 8 valve heads, so old external injectors work. we shall see. :)
 

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The engines you have are probably the QSB4.5-30 type. Looks like a 4bt 3.9 but is 4.5L, If you are going to build one there are some things you need to consider. First, those engines came with the VP30 injection pump which is electronic. You can convert it to a mechanical VE or P pump if you want. May need new injectors depending on what pop pressure those have. Second, those engines are not designed to be high performance units. I believe max HP offered was 99. They were high torque industrial engines. An issue you get into is the crank and rod angle. Those engines are the same bore as a 3.9 with a longer stroke. You'll find they have a lot of unique parts. Block has about 1/2" taller deck, crank is longer stroke, push rods are longer, and injection pump was electronic. We have a member who is currently building one of those. Might read his post. QSB4.5-30 to VE Pump Build Has Started
 

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The engines you have are probably the QSB4.5-30 type. Looks like a 4bt 3.9 but is 4.5L, If you are going to build one there are some things you need to consider. First, those engines came with the VP30 injection pump which is electronic. You can convert it to a mechanical VE or P pump if you want. May need new injectors depending on what pop pressure those have. Second, those engines are not designed to be high performance units. I believe max HP offered was 99. They were high torque industrial engines. An issue you get into is the crank and rod angle. Those engines are the same bore as a 3.9 with a longer stroke. You'll find they have a lot of unique parts. Block has about 1/2" taller deck, crank is longer stroke, push rods are longer, and injection pump was electronic. We have a member who is currently building one of those. Might read his post. QSB4.5-30 to VE Pump Build Has Started
No, the ones I have were mechanical, not with a VP30 pump.105 hp. The longer stroke means more torque. I will use the 8 valve head because I already have the right pistons. Injectors are cheap, and I can set the pressure to what I want with the proper shims. I have built and tested injectors many times.
 

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Do you have a serial number on one of those engines. I had heard there were 4.5 engines with mechanical pump but have never run across one. All I've seen were the model CM550 which has the VP30 pump.
 

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No, I can't open that. Just give me the serial number. Should be an 8 digit number. I have seen some new 4.5 engines with VE injection pumps that are coming out of the Cummins factory in Brazil.
 

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Yes, that is a B4.5-99C built 2/19/2005 in Brazil. CPL # 8204 which was 99 HP @ 2200 RPM and 305 lb ft torque @ 1500 RPM. A general industrial engine used in skid steers, gen sets, etc. Standard injection pump was Cummins part 3957698 built by Delphi. To change over to a mechanical pump can be done. You'll need a VE pump and drive gear. I believe the pop pressure on the injectors is wrong so you'll either have to rebuild those or buy replacements with the 245 bar pop. Not sure if your head has 9mm or 7mm injector holes. The build listed in post #7 is doing exactly that type of conversion. Not sure how far you can push the power level but have seen some listings as high as 180 HP.
 

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7 mm injectors. Not a problem for me to custom build injectors. pop pressure, different tips with number of holes and spray angle. I also get a discount on parts from Cummins. Even get stuff donated every now and then. I’ll port the head. If I can get around 250 hp with that kind of torque, I’d be happy.
BTW, how can I post with out adding the quote. When I click reply, it puts all the text from the previous post. I just delete it.
 

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You're probably not going to push a 4.5 to 250 HP. That longer stroke engine does not have ideal rod angles to go to that level. The only 4.5 that would be likely to stand up to that power is the 16 valve models which have a different bore and stroke. You can try it but you're going into an unknown area. Also, 250 HP is getting to the point of needing twin turbos. A Super HX30W may get close. You'll need a set of 5x.012 injectors which is what the 250 HP marine 4bt had only you'll need them with the lower pop pressure. Many dealers have those.
 

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Yeah, I am not too familiar with the smaller Cummins like the 5.9 and 6.7 :) This is my first foray into the four bangers. And only then because I was given the engines.
The ISX 15 is more in my area. And the 16L DDA, John Deere, and Caterpillars. Although we did just build a 12 valve that is going in a 1992 Ford F250. Our excavator even has the old NH 855 big cam Cummins in it. LOL
Anyway, we shall see what we can get out of it.
 

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Well the 4.5 engines you have are essentially an industrial 4 cylinder version of the 5.9 with a longer stroke. Except for the electronically controlled injection pump there's nothing fancy about them. We haven't had a lot of people doing that engine until just recently. They aren't all that common and were never used as a road engine. Doesn't mean it can't be. They have a tremendous torque to HP ratio of around 3:1. Base road engines like the 3.9 or 5.9 were 2.5:1.
 

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Well I would if I knew how to do that. Hey, I’m new here! I don’t even know how to post pictures. I just figured out how to post without adding the quote. 😂
 
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