Has anybody ever figured out just how much HP a 7.3 block can reliably support? Skip all the other problems. This would be my first concern. Then driveability, then $$$$. Well maybe not that order. TTT anyway.

 

Thats probably the most important question that needs to be answered.

 

Mike, that's kind of a tough question. With the limitations of the HEUI system, we've seen it's not that much, unless the block is strengthened significantly with the use of girdles an block filling. The HEUI system, at this point in time, simply does not allow for the control of the fuel, creating too much torque at the wrong time, thus splitting blocks.

However, with the proper control over injection, I think the block itself can withstand some pretty significant HP numbers. To look at DO again, granted it is a filled block, but having proper control over the injection event via mechanical pump, we can see the block is capable of handling some very large HP numbers. IIRC, Ben has broken or bent a few rods, with the block holding strong. I'm not 100% on that, but that's what comes to mind when I try to remember.

I'm thinking once the injection event is under better control, the fears of the block splitting will be significantly less than what they are now, and the block itself will be capable of taking the 800-900+ HP numbers that the others brands are putting out.

 

I hear what you are saying Jeremy, but I also feel in the back of my mind that he has about 10 times the investment in fueling, tuning, and charging than the block. Destroying a block looks like small beans to me and we're not likely to hear about it. I sure hope you're right but evidence dictates otherwise. I have a healthy block for now, just crappy rods, but if I got what I asked for it should outlast my tranny.

 

I have no doubt that he's got a ton of money wrapped up in the fueling. I want to say he's got $50K in just the heads to get the injectors and stuff in there. The whole motor is estimated to be at $100K, IIRC. I would just think that with as much attention as his truck gets, someone would post about a broken block. I know I've seen a few posts about mangled rods. They may have taken out the block, but the rods gave out first, rather than the block.

Honestly though, I don't know and you have a very valid point. It's may very well be something that's happened and we have no idea about it.

 

Mangled rods in a rotating assembly. Hmmm. Do you have any input on what that can do to a block? To be truthful, we don't even know if the main webs may have given up the ghost leading to mangled rods. We just don't know. I do know I have heard of blocks cracking in lesser trucks. These had all the "goodies" to protects the rotating assembly and of course the girdle.

I know I sound pessimistic, and I'm preaching to the choir with you, but again, why? Keep it real, be happy, or move on. That is my opinion.

Dockboy gave up for a reason. He blew enough 7.3s for me.

 

What's the price of this...

YouTube - Stroked Out starting and running


I'll right a check now!

 

Deereman, whats this "we" stuff? lol

To start off, the 6.4 heads use 4 bolts per cylinder, instead of 6, so it wont even be close. Putting them on the 6.0 is a better option, and even then im not sure the valves would fit down in the cylinder.

The HP is not the problem with splitting blocks. Its the torque. A non-filled 7.3 block even with a girdle (a girdle doesnt really help, WHERE they tend to split) will support roughly 1500 lb-ft of torque, before they like to crack. It's just the grade of cast iron, and the V shaped design that just rips itself apart. The block filler is where this really helps, bottom area of the water jackets, and the cam webbing is greatly strengthened when you fill the bottom half or so of the water jackets. But the problem with the HEUI system in the years past (cant say currently!) was that it could not fuel heavily over 2800rpm, limiting power. So, to get a higher power number, you would have to increase torque, to get a better power number. Advanced injection timing and longer pulsewidth was needed, larger nozzles to get the fuel out quickly, etc. Because HP is just a function of TQ and RPM, that would mean if you got 1500 lb-ft at 2400rpm, you would have 685hp. Now, with the current electronic modifications, and the injector porting methods being tested, you can get say 1300 lb-ft at 4000 rpm, which means LESS block splitting torque, but a ****load more HP, 990 to be exact. Think that's not possible? How about more realistic numbers that people put down, say 1150lb-ft at 2600rpm= 569hp. Seems like a few guys out there easily make that. Now, if you can stop the injectors from falling on their face, and make that 1150lb-ft, up around 4000rpm, thats 875hp, without adding any more torque load to the engine. Does that make sense to anyone?

 

He gave up too soon, IMO. Yeah he is making tons more power in a 5.9 now, however, I *think* he didnt have a filled block, which is what really holds the block itself together at high HP levels, from the inside out. It seemed like right when he gave up, swamps and a few other guys came out with IDM/ECM and injector mods that will make 2009 a BIG *** year in 7.3 powerstroke performance.

 

I'm smelling what your cooking here Kris! Hence we (some of the tuners), now understand the work around for the revlimiting and how to control the injection event and torque output at higher rpms, thus we ARE going to see more high horspower trucks in the near future.

 

Kris, we've talked about this before, so you know what I'm about to say, but I won't believe it until I see it. The performance companies have been saying it for years that this next year is the big one for the 7.3.

Every winter since '04 or '05, it's always been, "Man, this next year is gonna be the year for the 7.3," but it never happens. It would be nice to see someone actually do something with it, instead of just saying that they're developing this or that, which is gonna be the key.

One other thing to think about. While the 7.3 is definitely getting more powerful, and looks to be able to make 700-800 HP reliably, keep in mind the CR trucks (both Cummins and D-Max) are now breaking the 1000 HP mark on a relatively regular occurrence. I'm afraid that the 7.3 is always going to be a couple years and a couple hundred HP behind. That doesn't make it a bad engine, just not the best platform for building big HP, IMO.

 

Take all the time you need cause I can promise you that people already are where you want to be in a year from now

Cowboy Steve

 

Yea, even with my vast knowledge on the 7.3 I understood

 

Agreed, nobody is going to go out and set the world on fire with big HP numbers, remember this is a powerstroke

Cowboy Steve