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Discussion Starter · #1 ·
I have a little history with a buddies Ram 50 with the 4D55 in it, and I adjusted the Full Load screw and put a full 3" exhaust on it. But... It dyno'd at 89 horse and 147ft lbs of torque. Stock turbo pushin 23lbs of boost on the gauge, it pushes 1200 degrees on the pyro, but it doesnt run very impressively, and it eats head gaskets. Scary, I thought.

The Ranger, so far is bone stock. I need some teachin on the best way to tune this little engine. I want to get more torque, keep the EGT's low, and get some great fuel economy. I really wanna know how to do things like timing advance, and what is safe to do to the pump without granading the head gasket. I plan on using a "Ford" IHI turbo off the Ford 2.3L Turbo gas engine and a front mount intercooler. 15 lbs of boost? How far can I safely go? Performance parts? I know this is a knowledgable forum, and Im positive Ill get some great info here. Thanks guys!
 

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4d55

The power numbers seem low for such an unreliable engine. The EGT seems very high, is that before or after the turbo? The 4d55-56 I worked on were very reliable but they were also stock or close to stock.

As for your friends engine two things come to mind. Overfueling and or a bad head or block surface. Unfortunately I can't tell you when when the engine becomes unreliable because it was turned up to high. You could go with a bigger engine but that has its own set of problems.
 

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Discussion Starter · #4 ·
I have a feeling the head surface is not good and true on his. Also, that EGT reading is after the turbo.

The turbo I plan to use is a lot larger on the exhaust side, but just a little bigger on the compressor side. It is internally wastegated and water cooled. Also, the turbo shaft is supported by bearings, not bushings. So it should last longer and spool easier with less backpressure.
 

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1200 is too hot for a probe downstream of the turbo. The best thing you can do is move the problem to the exhaust manifold or even the turbo scroll.

If that IHI is an RHB5 or RHF5 then it's about the right size. But they came with a whole range of different size exhaust housings.
 

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Discussion Starter · #6 ·
Im not too worried about his anymore, I just dont want that happining to mine. Ill look at the IHI's I have available to me. I know all of them I have here have a good size exhaust side on them and I figured that would help with the serious backpressure issue. Any ideas on the timing advance? Thats what Im really interested in...
 

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What is this backpressure issue?
For turbos a lack of boost is what causes high EGT's. Anything you do in an attempt to reduce turbo backpressure (i.e. bigger turbo or bigger exhaust housing) will reduce boost and increase EGT's.

To get EGT's down you need a smaller exhaust housing to spin the compressor harder and generate more boost.
 

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I would say there are two questions here. Why is my friends truck unreliable? And how should i modify my engine? My 500 hp N series Cummins got as hot as 900f after the turbo as is common fitment on trucks. That is pulling a heavy drop deck up a mountain.

1200f after the turbo is too much. too much load, too much fuel, too much advance, not enough air.

If you have the VE stile pump you can start by turning up the full fuel screw and advancing the timing. Start with small increments, also you should know that I read about a killer dowel pin analogous to the one on B series Cummins.
 

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Discussion Starter · #9 ·
I need to be educated on how to adjust the timing. And I'd like to know about any other adjustments that can be done to the pump. Mine is bone stock in a 85 Ranger. I dont know if the pump was different with the year or for the application.
 

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As far adjusting the full fuel screw and the timing the same basic principals apply to the Bosch VE pump. I am not sure if your engine has a centrifugal advance between the pump and the gear, if it does check that its working properly.
 

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83 4d55 injection Pump

Were can you get parts for the pump or get a rebuilt one at? I have been searching for a while but keep finding overseas sources. I just bought an 83 mitsu but the pump definetly in need of a reman.
 

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pump

Any competent shop can fix the pump. There are lots of other modifications to make more power, it depends on how much you want to spend and what you are after.
 
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