NTC 400 Mo Power

[eldgenb]

Well, I may very well the first person in the world to actually post a picture of where these items are and how to do it, I could find plenty of half baked descriptions but no pics anywhere so this was a praying moment for me. I talked to Ross REB87 Who saved me from drilling the item that I thought was right and led me to doing more research before I did anything. What this thread is about it how to drill and adjust the fuel screw on the NTC 400 found in the m915 series trucks. "I am in no way wanting you to do what I did due to the fact that it alters your emissions for your truck and after this procedure and following procedures I returned all items to stock to remain compliant" Ok now that's over with lets get started. You will need a sharp punch, hammer 1/4 and 1/8 drill bit, a long screw roughly close to the 1/8 size drill bit and a very skinny screw driver. I also plan on shimming the gov. and adjusting the fuel aneroid to get the most safe power out of these rigs. If you adjust these you take everything into your own hands I will not be held liable for any changes you make.

Firs off you have to find the tamper safe brass ball on the end of the throttle shaft NOT THE LEVER. It is in the end of the actual shaft. You need to center punch it and use the 1/4 drill bit first. You will drill about 1/4 inch out of the ball that is in there and stop. You will then use the 1/8 drill bit to drill the rest of the way through. Then you will use the screw and try to thread it into the 1/8th hole and pull on it to remove the remaining pieces of the ball which will expose the screw inside the shaft. To increase the fuel you will turn it counterclockwise until you reach the desired power, word on the street is 6 full turns. and thats it. I noticed it drove kinda like my truck but a lot angrier and with almost no lag for spool up. I will keep you posted on the other mods over the next few days.

 

[eldgenb]

by the way since I know it will come up many will want to know what this actually does. Well the fuel that enters the pump first passes through the throttle shaft. The screw that you adjust limits the amount of fuel that can be sent to the injectors, when you open that choke point up it allow the engine to fuel much more, I will see how it goes when I get deeper into mods and I will try to come up with a gauge that monitors my fuel pressure, 225 psi is about as high as you want to go. I will do the dual fuel line mod which you basically remove a plug on the front of the engine, t-off the fuel line out of the pump and run fuel from both side of the engine, this keeps the forward cylinders from succumbing to low fuel pressure because all of the rear cylinders depleted it. The main reason for me is 20-25 hp gain and a much more responsive throttle.

Oh and Soni, please link this into the 915-920 tech and tips when you start the new one.
Thanks.

 

[86m1028]

Thanks for the info

Please keep us posted on the outcome.

 

[Bighurt]

by the way since I know it will come up many will want to know what this actually does. Well the fuel that enters the pump first passes through the throttle shaft. The screw that you adjust limits the amount of fuel that can be sent to the injectors, when you open that choke point up it allow the engine to fuel much more, I will see how it goes when I get deeper into mods and I will try to come up with a gauge that monitors my fuel pressure, 225 psi is about as high as you want to go. I will do the dual fuel line mod which you basically remove a plug on the front of the engine, t-off the fuel line out of the pump and run fuel from both side of the engine, this keeps the forward cylinders from succumbing to low fuel pressure because all of the rear cylinders depleted it. The main reason for me is 20-25 hp gain and a much more responsive throttle.

Oh and Soni, please link this into the 915-920 tech and tips when you start the new one.
Thanks.

Have you messed with your fuel button's?

Only reason I ask and this is a big deal when you start messing' with diesels fuel. When you begin to increase the fuel beyond the factory settings your EGT's increase, this can be bad. I'm not saying not to do it, most of these trucks are emissions exempt anyways.

It should be recommended to anyone swapping out buttons and messing with the the throttle screw that you should have a pyrometer installed to watch your EGT temps. There is a reason why Cummins installed the tamper-proof ball......

I wish I could just win an auction so that I can play too...

 

[eldgenb]

Have you messed with your fuel button's?

Only reason I ask and this is a big deal when you start messing' with diesels fuel. When you begin to increase the fuel beyond the factory settings your EGT's increase, this can be bad. I'm not saying not to do it, most of these trucks are emissions exempt anyways.

It should be recommended to anyone swapping out buttons and messing with the the throttle screw that you should have a pyrometer installed to watch your EGT temps. There is a reason why Cummins installed the tamper-proof ball......

I wish I could just win an auction so that I can play too...

No I have not done any buttons, I do not plan to. This is in place of the button, I visited with a cummins pump guy here locally and he said that he would recommend adding fuel before adding pressure, he also gave me a bunch of shims and told me 30rpm per shim. I truly believe that these trucks are easily and safely capable of another 50-75 hp without any concerns, I do not plan on doing everything to the truck, just select what is cheapest or in this case free and best for my use. The gov. shimming will just raise the rpm in which the pump defuels and the aneroid just dictates when the trucks begins to fuel, at least how soon pre boost. The fuel screw is the only power adder beside the dual fuel lines I intend to do.
I agree if you do more than one adjustment power wise you need an egt gauge, matter of fact I think everyone should have one anyways, cheap insurance.

 

[WillWagner]

6 full turns will give WAY more than 20-25 HP!!! 1/4 turn out will give 20 or so HP at rated RPM. In to decrease, out to increase.

 

[eldgenb]

6 full turns will give WAY more than 20-25 HP!!! 1/4 turn out will give 20 or so HP at rated RPM. In to decrease, out to increase.

oh yeah I figured that, 6 turns is the max I will go. I am thinking around 75hp, the 20 ish comes from the dual fuel lines, just makes sure every cylinder gets its fair share is all.

 

[Bighurt]

o dual fuel lines, just makes sure every cylinder gets its fair share is all.

I assume your running the second line to the #1 cylinder port?

This mod was discussed on TDG some time ago, wise mod if you ask me.

Jeremy

 

[eldgenb]

I assume your running the second line to the #1 cylinder port?

This mod was discussed on TDG some time ago, wise mod if you ask me.

Jeremy

yes to the #1, the theory is that by the time the fuel reaches the #1 cylinder since it starts from #6 the pressures is pretty low, by doing the mod you only gain horse power that should have been there to start with and I think it decreases the chance of a lean burn.

 

[WillWagner]

Diesels don't have rich and lean burns. Gasoline and gasseous fueled engines do.

 

[Bighurt]

yes to the #1, the theory is that by the time the fuel reaches the #1 cylinder since it starts from #6 the pressures is pretty low, by doing the mod you only gain horse power that should have been there to start with and I think it decreases the chance of a lean burn.

It's not so much therory as it's proven in over the road trucks and I don't think there is any measurable HP gains. Realistically it it just balances the fuel amongst the cyclinders. Which when over fueling prevents stressing one more than the other.

I use the term over fueling in reference to fueling over stock rate.

If you did not fuel equally and increased fuel amount to near make the amount of fuel buring in cylinder six would do some serious damage to the piston. We've seen it on the PT trucks here. During and over haul the rear pistons got progressivly worse, they all had to be replaced, and I believe the cylinders had to be bored over and sleeve from the damage.

Of course with the danger comes sheer power.

Jeremy

"Real trucks don't need spark plugs"

 

[promodhotrod]

Thanks for the pics eldgenb. I can vouch for the use of the dual fuel line kit, my 916 runs smooth like an ISX, where it rattled like a coffee can full of marbles originally. However I have not adjusted the fuel stop screw. I'm still ciphering on the best way to up power as I dont think these engines will have any issues whatsoever in the 5-6 C HP range. I do believe I will do the variable pump timing mod before going after more fuel. I know some truckers running 800 + on the big cam with no longevity problems, but they both run variable pump timing. Thanks again.
KJ

 

[Avalanche]

I have heard of the dual fuel line modification but have never actually seen it done. It does sound very simple. The guys at Pittsburg Power highly recommend it and say it has made an additional 20-25 HP on the dyno. Do you have any pictures of which plug to pull for the #1 cylinder. I have a Big Cam 3, a Big Cam 4 and a Big Cam 1. Is the dual fuel line mod relevant for all BC engines? Thanks...

 

[promodhotrod]

Avalanche:
We just ran an additional stainless 3/8 hard line to the front heads fuel gallery pressuse tap. To tell the truth I havent figured out all the differences between I II and III, I think its all in the pump turbo and cam grind. Mine are I's (I think), but Im sure any series that is feeding a fuel gallery from one end with a small single line would benefit.
KJ

 

[R Racing]

I wonder if this would work on the 250 ? Like as a fuel compensation if you add a small turbo ?

 

[eldgenb]

Avalanche:
We just ran an additional stainless 3/8 hard line to the front heads fuel gallery pressuse tap. To tell the truth I havent figured out all the differences between I II and III, I think its all in the pump turbo and cam grind. Mine are I's (I think), but Im sure any series that is feeding a fuel gallery from one end with a small single line would benefit.
KJ

can you take a picture of where you split the line for the dual fuel, I feel like I am pioneering my way through this since I cannot find any hard fast how to's or pics on the net. What kind of line did you use, I assume pressure fittings to keep it from leaking, a parts list would be nice if you can remember what went to it. Anyone can feel free to add power or must do's on this thread as long as it is explained well and hopefully supported by pictures.

 

[Bighurt]

can you take a picture of where you split the line for the dual fuel, I feel like I am pioneering my way through this since I cannot find any hard fast how to's or pics on the net. What kind of line did you use, I assume pressure fittings to keep it from leaking, a parts list would be nice if you can remember what went to it. Anyone can feel free to add power or must do's on this thread as long as it is explained well and hopefully supported by pictures.

http://img267.imageshack.us/img267/158/img0089v.jpg

Here is the front fuel line.

Tons of posts out there but your right not a lot of pictures. These engines where used in over the road trucks and Combines, so there are plenty of them out there looks like most just walk through the procedure.

 

[eldgenb]

Diesels don't have rich and lean burns. Gasoline and gasseous fueled engines do.

Thank you for correcting me, hand are getting faster than my brain now a days. What I was trying to say is the rear cylinders experiencing more heat due to increase fuel and not having a well balance engine as far as power and distributing it evenly.

 

[Floridianson]

So with increased fuel demand do you feel that the lines leading from the tank all the way to the pump are large enough? Do we leave them alone or try to increase there size to?

When you split your lines would you not just split them as the came from the pump and one runs to the front head and one to the rear head?

 

[Avalanche]

Thanks for the info everyone. I will be working on the 915 this coming week and will start sorting out this dual fuel line mod. I think it has a BC 1. I will take some pics as it goes together and make an attempt at posting them. I'm computer challenged so it will probably take less time to do the modification than post up the pictures...