Time for Big Cam rebuild..550Hp...Taking suggestions

Not sure where to post this question but here it goes. Found a truck with big cam 400 that dropped the #6 piston. What would it take to get the motor back on track? I guess i already know the answer, compared to a 4 wheeler motor. You drop a piston in a 350, you rebuild the motor from bottom up. Is that what I am looking at here?

 

Pull the #3 head and then the #6 sleeve and piston along with a set of rods and mains into the motor would be a start. Check the Head for Damage along with checking the turbo to see if it caught any metal. Best thing to do would be OH the whole thing and do a couple upgrades like upgrade the cooling system to High flow instead of Low Flow and add a Duel fuel line kit plus a couple other quick things to do.

 

One of the tricks a customer of mine did was put in the 475 injectors, with rail pressure maxed out with a very small button and RPM's set about 2600. This was a stock engine with the changes I spoke of. It put 400 HP at half throttle on dyno and was used for racing. The only problem was when it was hot it would not shutoff without popping clutch.

 

After talking with a good injector shop on multiple occurences I feel that the injector must match the cam, as there are different lift specs depending on the engine. The 475hp engines used a cam that had more injector travel than the standard big cams so when you switch one of the high lift injectors into a normal lift engine, depending on the setting procedure you use you have a very sloppy injector or one that you arent getting full travel out of.

 

Some think that they are all the same just put different hp injectors and turbo on it it will be a big motor then. I think a little different mix matching parts very seldom works well, pressure is important but flow is more important in most cases timing is critical and knowing which way to go. Amount of fuel and torque rise can make all the difference. The idea of building a muscle motor has about been lost in this electronic age of ECM files and upgrades I am not saying they ain't handy as a pocket on a shirt but put some muscle with your file if you really want bragging rights. Back to the manual cummins getting 550 hp out of a big cam and getting it to live is doable without moving a mountain. Trying to get 550 hp out of a big cam on a low dough budget and getting it to live stay cool and be dependable doubt it. My 3406B puts out well above 550 keeps pretty close to 900 degree pyro and 190 coolant temp when pushed hard other wise it stays at 180 or so but it wasn't cheap. Whether its CAT Cummins Dripping troit Mack or a briggs and stratton you get what you pay for especially when they are pumped up.

 

I would like to dyno mine after I go thru the engine this winter, but I have heard some horror stories involving hopped up big cams and the dynos at cummins bridgeway which would be the closest one to me, and I dont really feel like traveling just for a number.

 

What hp do you guys think a bone stock 400 big cam with air to air can run, daily, without reducing the life of the engine?

 

I don't recall them having air to air or am I wrong

 

No, big cams were never offered with air to air, that didn't come about till the first mechanical N14s.

 

That is correct, but by using the intake manifold from.an n14, a CAC can be used instead of the stock aftercooler. (This is a transplant into a truck that originally has a CAC)...

So what do gou guys think is a "safe" hp for a stock 400 big cam with air to air? Safe meaning used daily, with the same engine life of a stock engine.

I think my question is mainly about turning up the fuel, maybe recalibrating the pump and flowing the injectors, better flow air cleaner- simple modifications just to improve the stock situation.

I am not particularly looking to change the timing, but would that help a stock
engine to be safer with more fuel? At what hp is that needed and up to what horsepower could that run to (safely)? And would that affect starting and idling?

Honestly, I am wondering if 500 hp is safely realistic. I would think at 450 to 500 hp the engine would run better, have more power and be easier on fuel. Thoughts?