Rebuild on 300 Cummins

Personally I'd just roll bearings in, dropped maybe 5 numbers on the button, back off the AFC adjustment a little bit, and shim the idle spring enough to give you about 2500 RPM high idle

Buttons are cheap and easy to change, if you think dropping five numbers is too much or not enough you can always change it a few numbers either way.

Go online and look for Cummins idle spring plunger, that's technically what the button is called. Last time I bought them I think they were maybe $10 each. The lower the number the more fuel it's going to inject. They're under that little cone on the back of your PT pump, the one with the plug on the end of it that you take out to adjust your idle speed.

 

I need your help ASAP.
I have problem with my NTC300 CPL is 471
I need to order rebuild kit for this engine but I can't find any good source and kits wi h support CPL 471.
I read your post about upgrade 300 to 400 and need some advice from you please .
I have picture from engine with all data if u need it
Please let me know if u can help
Thanks in advance
Zack

 

He can help or ?

 

There’s parts available out there still, mostly aftermarket. Power Products in Kentucky has been a good source for me in the past.

Upgrading from 300 to a 400 is not always as easy as some may think, more involved than just injectors and the pump.

I would look on top the pump at the little tag to see what its calibrated for to insure it’s still at 300. Never know someone may have tried to convert it to a 315 or 350…

https://powerproductsky.com/

 

The guys on here helped me tremendously when I went from a 290, to 350, in a small cam. It was a big job to do it correctly. “Correctly”, means changing the timing at the cam gear, along with cam follower box, shims. Shims, may all be the same but could also be individually different. After all that was done, fuel pressure was increased at the pump, as well. Truck is running great and very little smoke. I don’t think I’ll do another, like that. Easier, not easy, to find a decent BC 350 or 400 and build it. I would recommend building one and converting it from water to air, to air to air, provided you have room for a charge air cooler. Not necessarily a must but something, I would do.

 

Are you the man I sent cam follower gaskets to…?

 

Yes, sir. Thank you, again.

 

You’re welcome, I just couldn’t remember who it was lol….