Cummins Big Cam 400 motor in a Pete 377?

What size tires are on it? That will make a big difference as to the top speed. If it has 11R24.5, then top speed will be around 72 at 2100 RPM.

300k miles is starting to get long in the tooth for a big cam rebuild, but you should be able to get another couple of hundred thousand out of it. Just keep treatment in the anti-freeze to keep the liners from pitting.

Also use a stop leak called DIKE, available at NAPA and most Freightliner places. This is for the water leaks around the head that 99.9% of all big cam engines have. This stuff will absloutely stop leaks, and not clog up anything. I have used it for years, and so have most of the mechanics I know.

One more thing, use a lubricating fuel treatment in the fuel. The 15 PPM low sulphur fuel out now is very hard on the old style pump and injectors without a fuel treatment added.

Expect about 5 to 5.5 MPG. The 4.11 rears will make it pull good. For what you are going to do this sounds like just what you need.

The best thing about these engines is that parts are cheap, plentiful, and they are easy to work on.

 

Good engine but prone to over heating problems as they are what they call Lo flo system .Worse thing you can do is to use stop leak you will have major problems with cooling system . I put a Cummins RECON engine in my 88 Pete March 08 and this yr we had overheating problems we put new bigger radiator core , water pump and the 2 thermostats and still had problems to cure it and still keep engine warranty we had to swap flow directions of engine coolant it was pulling return water to the engine off the top tank ,Now it is pulling off bottom so far so good I about went crazy before we got it figured out of coarse Iwas thinking of the lost revenue That I was missing out on to the turn of about $4,000.00

 

I have the ntc 400 big cam in a 1989 Freightliner classic. This is basically the precursor to the N-14 and not much different. This is an all mechanical motor. I was bobtail and had my wife in the car beside me, so I put it to the floor to see what it would do and check my speedometer. I got it up over 100 mph and had more pedal to go. It does have the 13 speed with 373 rears though. It's a very good reliable motor.

 

You need to get the model number off the trans and look it up on the eaton site. Overdrive ratio will be critical to determine max speed. We have a 78 Pete with an old RTO thirteen speed. The OD is .86 (IIRC) which makes it hard to get much over 70 with 4.11 rears. If it had the .73 ratio it would be much better. Back in the day of 55mph speed limits (remember that?) the OD ratio was way less important.

John

 

I need More reviews about this engine. Bad or good ,I knew about the cooling issues. I’m trying to make this engine bulletproof

 

Opti-lube would be the only treatment I use these days, you can order off of their website. Link below. Use the the red bottle XPD as a complete treatment or purple XL for lube.

Opti-Lube Diesel Fuel Improver Additive | XPD | Summer Blend | Winter Blend | DFI Accessories

If you drive these engines properly they will last a long time, they like RPM, dont pull them under 1600rpm.

 

look up on passengerside of block for number. is it a gen I, II or III
maybe IV

look up

big cam 400 cummins tricks

dont count this motor out. its like the chevy 327. its an amazing motor.