Big Cam 400 in 81' Peterbilt. Motor seems doggly and underpowered compared to others I have driven. I am considering having the overhead run, and turning up the pump. Any other ideas? How much can I turn it up without heat issues? Thanks.

 

Welcome to the site. I moved your thread here so you could get the best answers from the right set of experts. Good luck to ya on this.

 

Thanks.

 

search low buck diesel power i have done big cam 400 this way .dont go to far you will melt pistons!! good luck

 

Crank it up until she throws rods out the side or melts pistons, get a new engine , and back it down a knotch or two next time

 

I drove an Autocar with a 400 Big Cam for about a month. That was a pullin son of a gun, probably one of the hardest pullin I ever drove. Get the overhead done and see how it goes. I hated that truck but loved that engine

 

Do the overhead, and put in a couple numbers smaller fuel button. Dont just jump to a super small number. Pull yours out, then a Cummins shop should have the right ones. There's plenty available online too.

 

Diesel Injection - Where the Strong Ones Come From go to "bruce's horsepower and torque articles" There is much more then A LOT of reading, but take the time to read it all.

Go here FIRST. You really have to read it all, there are little tips and tricks that if you start to just skim it, you will miss them.

 

i will tell you now your fuel lines are shot. get big lines and a bigger filter head. order bruces duel fuel line kit and turn the pump up. easy 75 to 100 hp. if thats not good for you get a retarded cam key, put more fuel to it. keep a eye on the EGTs if you got some money i can make that truck breath fire. i pulled a 7 axle 144,000 permit lowboy with a bigcam formula 444 for years. (in the fast lane)

 

FOR SALE CUMMINS BIG CAM REBUILT WITH NEW PARTS FROM PITTSBURG POWER CAM HEAD CERAMIC PISTON BEARING FUEL PUMP OVER $ 12000.00 SPENT AROUND 700 HP NEVER RAN SINCE REBUILT