Cummins 855 Small cam Injector Sizes?

Howdy again yall.

I am in search of the different size injectors for the 855 Small cam cummins. I have searched the web over and this forum and can not find a list of the injectors that fit the SC engines. Does anyone know of or can point me to a list of injectors that fit the SC engine? Or what is the biggest injector cummins made for the SC engines??

Would i be better off having mine rebuilt and made to flow more? If so. Who do you all think would be a good injector builder? I have talked to PP out of Saxonburg, PA. They said they could do it and increase the flow 10mm.. Are these injectors rated by MM or CC??

I am looking for more fuel to make more power. I have the done he dual fuel line. My injection (PT) pump is set to 220 PSI and its set so it fuels to 2500 RPMs maybe a little more. No load it spins 2700 dead on.


I have a lot to learn. Thanks for any help.

One place to call, diesel controls out of Ohio, do not do business with PP on injectors.

Injectors are flowed in cubic mm or mm3, or they can be flowed in CCs which is rated per 1000 strokes.

Depending on how much more fuel you want, change the button in the injection pump. The smaller the number, the higher the delivery rate.

SmokinCAT said:

One place to call, diesel controls out of Ohio, do not do business with PP on injectors.

Injectors are flowed in cubic mm or mm3, or they can be flowed in CCs which is rated per 1000 strokes.

Click to expand...

Thanks for the Information. I have read for the 350 SC the factory ones flow around 200cc? Is that right? Lets say the if the pump was set up to handle the extra fuel of bigger injectors. How much more power can be made for every 10cc over stock? With the proper air to go with it to.

jimbo486 said:

Depending on how much more fuel you want, change the button in the injection pump. The smaller the number, the higher the delivery rate.

Click to expand...

I am setting right now at 220 psi rail pressure. I have heard and been told that higher then that you will start to were the cam out faster. Since the SC has a smaller and weaker cam then the BC I was under the impression that going much over 220psi will wear the cam out faster. How true is that? I really do not want to have to tear into it to change out a cam just because i ran to high of rail pressure.

Cam wear is the reason i was and am looking at going bigger with the injectors.

With that said. What is a safe limit of rail pressure to keep from wearing the cam out to fast?


Thanks again guys!

On EDIT: I have a number 20 button in the pump now. And have a 12 I could put in there. BUT did not want to stress the cam to much.

Cam issues come from running high pressure with stock flow. Increased injector flow lessens the pressure put on the cam, I will need to look at the injector book, but they flow no more then what a 350BC injector flows which is around 170-175cc.

Ok that makes sense. I feel that going up in injector size would be the better way to make power without damage to the cam. That would be nice to know what they do flow stock.

Thanks for the leads.

It is. Takes pressure off the cam and pump.

My custom injectors are built so they operate best at around 375-400psi, any more and they start to dribble fuel on their own.

Thats a lot of pressure! Did you have to mod the injection pump to flow more volume to be able to maintain that kind of pressure with a bigger injector? Do you have one of the KT 1 1/4 gear pump feeding the injection pump? It would take more then just the fuel screw and a 00 button to do that kind of pressure right? Can i guy change the spring holding the button to get more pressure to? I am here to learn!

Yes, my pump with even 475hp twin turbo injectors makes north of 600psi.

If yours is just a toy, diesel controls can build injectors for your small cam that flow 300cc's, I would send them you pump as well and have them match it to the injectors.

Nice. I bet that feels good! Mine is not just a toy. I use it to haul hay. I hope to also use to haul grain to. So it will be worked. I would like to get it to be a little hotter then a NTC 400.

Sounds like a good idea. get them matched up like that.

Have injectors built to around 235cc, get you a holset HT60 part number 3804502, that should let you have a good workable power. You will need to set your pump after new injectors.

Thanks for all the help and information. I am also thinking about picking up a core PT pump that has the fuel screw in the shaft, since my currant pump does not. Then have it rebuilt the same time i have the injectors done. It would be nice to have that screw there so I can tweak things a little.

What size exhaust housing would you recommend? 26cm?

That's what size comes on that HT60 number I gave you.

ok Sounds good. Thanks!

How does a HT60 3837074 compare to a HT60 3804502 ?? It has a 26cm housing. I cant seem to find the specs on them. Is it not rated for as much power?

ON EDIT: That number keeps coming up as a cross reference number with 3804502.

The number I gave you is the most recent, that is the 460+ N14 turbo, I would only buy a holset, the Borg Warner version is not built the same as the holset.

You will need to grind the v-band down to just a slight lip enough to give the hose clamp to bite against.

Sounds good. Thanks for the information. I was thinking about just building a new air side pipe feeding the charge cooler. That way i could smooth out the flow and the way it enters the charged air cooler. The way you say would be the most simple.

Thanks again!!