PMRs have their advantages, there is no doubt. Smoother? Maybe. Accelerate better (Stock)? Maybe. But you forgot the biggest advantage: cost. Ford could save a little bit of money on each and every one. When you are talking hundreds of thousands of engines, saving a few bucks per engine adds up. Why do you think Ford took off the regulated fuel return that Navistar put on the engine (because blind fuel rails in a diesel are a terrible idea)? It sure as hell wasn't to make it run better!!

Here they could save (their cost) probably $50 or more per engine - that translates to over $50 million saved (maybe a LOT more) during the run of the 7.3. Advantage to the customer? A topic of discussion - namely, cackle.

Advantage to Ford? Well, they saved on the cost of the reg fuel return, but I'd LOVE to see a complete cost analysis to find out how much warranty money was flushed down the drain to deal with customer complaints. Oh, and PR wasn't so great either...

As for power limits on the forged - you bet!! If you want to make serious, big HP, you need to build the engine for it, and that includes premium high performance rods, NOT the stock forged ones.

On the other hand, if you just want a healthy boost from stock, I'd rather have a motor that has the stock forged over the PMRs any day.

 

isnt it funny that the 6.0 and the duramax make so much hp and use PMR's, although different in design, but none the less, still PMR's

 

Not really. The PMRs they came with were specifically designed for that application. My BMW motorcycle has forged rods, my brother's '67 firebird has weak, wimpy, cast iron rods. I can assure you the cast rods in his 'bird are MUCH stronger than the forged ones in my bike. It isn't just the material, it is the design and application.

PMRs work very, very well for stock or very nearly stock. On a 7.3 with forged rods, your limit is combustion chamber sealing and head stud strength. From everything I've read, on the 6.0, it is the rods. They have about the same problem with combustion chamber sealing and head stud strength as the 7.3, but you won't get to that power level before the rods become a problem.

Of course, this all comes from what I have read and heard - I don't have a 6.0. Don't want one. I have two friends with them. One sold his first one after it spent so much time in the shop, replaced it with a new '06. The other added intake, exhaust, chip, etc. Ended up ventilating his block with a rod. With the wonderful PMRs, I can't imagine why this happened. Go figure.