You asked for input, so here it is...

Why 400 HP?

I was dead set on modified injectors and stage 2 HPOP for my tow pig truck. Since finding a forced induction system and tune that work well, there is no need for the "high HP" goal, at least for my application. Last summer at 260,000 miles my tired injectors and HPOP towed heavy 5,500 miles up to 9,000 feet elevation. I'm good with that and putting the money to something else while keeping reliability, longevity and efficiency in my crosshairs.

When/if my injectors or HPOP die, OEM replacements will go back in.

I am not trying to change your mind or be argumentative. You asked for input and if we were having a conversation in person, I would ask you why. Or, I would say you need to ask yourself why.

 

Good points. It'd be about 2300. I could make up some cost by selling my forged rods and the ARP fasteners but it wouldn't be much.

I figure it'd be overkill... I guess I'm wondering if it's a reasonable to trust that the forged rods that came with the block have enough squash/stretch cycles left in them to not perm deform in another 100k miles of use while reaching double the torque, at lower RPM than they were designed for?

@Sous That's a great question. I guess it's a matter of "if I'm going through the expense, stress, time of building this engine from the ground up, it'd be nice to have more contemporary levels of power on tap". I didn't plan on having to tear the thing apart when we got it.. if I had known that was going to happen I probably would have used the money to buy a newer rig with more power and less worry. That being said I've learned a lot through this journey which counts for something.


*EDIT* I got a call back from a local reputable outfit that does shot peening. I think that would probably land me where I need to be in terms of of stouter than stock while avoiding the overkill of billet rods.

 

If 160/30's and the 364.5/68mm make 350-375...400 sounds good to me. That would be about my limit as the supporting mods start getting real money

Sous, if you towed with 350hp....you'd understand it.

 

Shotpeening coupled with cyro...solid plan.

 

You think it's worthwhile to do both? Don't have a cryo place in the area so I'd have to send them out. Would it matter the order?

 

From my understanding, and please correct me, but shotpeening creates a sortt of surface stress...compacting the outerlayer of material.

I would think that cyro would be a natural complement to that treatment.

You're super inquisitive about these things...I'm sure you'll gather the data you need to choose the correct path....for you.

 

 

That was my understanding as well; cryo is stress relieving through the entire piece, shot is is stress relieving and work hardening the surface. I get the feeling this all would help with preventing cracks and fatigue related failures, but I'm more worried about a bent rod vs a cracked one.

Idk figure 200 for shot, 200 (guessing) for cryo—maybe more if they need to be ground, 50ish iirc for new pin bushings, another few hundred (might be less, would have to ask) to resize the big end for arp bolts and install/hone pin bushings... Adds up and all this work could be undone by one rod that bends slightly.

Gonna have to really think if all that is worth it vs selling the rods and arp bolts for like 500 and getting Crowers and the peace of mind that would come with em.

 

I’m sorry, what injectors are you going with?
Still using the 363/68/.91 correct?

Brokestroke has been running the 363/68/.83 combo for a while now which causes boost (+ extra cylinder pressure) much earlier than what most of us are seeing. Stock AD’s with stock bottom end, sorry can’t remember if he has PMR or forged.

I think anything beyond forged is likely pretty overkill unless you’re planning on some really large injectors. Mind you, I have no experience building a 7.3, just basing on what I see others doing.

With the luck you’ve been having I wouldn’t want to ship anything out unless absolutely necessary.

My 2 cents.

I’m really anxious to see you enjoy the wonderful results of all your work.

 

Most/all of the time you will be running a tune thats useable, so max about 375-425 hp wot. Billet rods for that is a waste of money for that imho.

If you want to play in hot tunes like that graph, then yes get them

 

Perhaps, but there is a fine line between wanting more and having enough. I learned that lesson a long time ago on another engine and vehicle.

Being able to move 18,000 - 20,000 GCVW up a grade at a steady pace is "enough" in my book. I get it though that people want or need more and I encourage them to pursue that.

I hope PriusLover is able to attain a well running 7.3L before we see January 2024.

 

On the other hand, some of us have learned more is never enough…

 

Ive towed 15-30k alot of miles over 10 yr period with 450-500+ whp in three trucks, one of which had more than just tunes.
its incredible, but I'm with sous. I want my stuff to last.

 

Another factor in the equation is slapping a turbonator on there at some point. That's going to bring cylinder pressures/torque on even sooner.

The engine core I got came with a front cover, transmission spacer, and original HPOP, so there's a bit of coin to work with from those items. I'll have to ask the machinist how much it'll cost to machine/balance the stock rods, but from my estimates it seems like Crowers would put me at 700 out of pocket all said and done.

 

I’m FTN abd I approve this notion. Go with the new T6 version with the HD actuator.