Having had a 2000 F-350 lariat PSD crew cab ,I read somewhere about the conncting rods for this engine some were forged and others were the compressed iron , it mentioned about serial #'s Does anyone know which ones had the forged rods ? thanks for any help Glenn

 

Moved to the 1999 - 2003 7.3L Power Stroke Diesel forum.

 

Im fairly certain that with the 2000, you have forged rods, so you lucked out. Someone with the serial #s should come along and be more specific, but I think they started with the powdered metal rods sometime in 2001.

 

99's and 2000's had forged, 2001 was hit and miss, 02 and so on had the powdered metal rods. Thats what I think, but don't hold me to it

 

Here's a good write-up for ya!

PMR VS FORGED... ( the write up ) - Ford Powerstroke Diesel Forum

 

I've personally seen one that should have had forged and didn't. I've also seen two the other way as well (one was this week). This was going by serial number.

The ONLY way to know for sure is to visually check. Seriously. Don't be lazy and assume based on a list of serial numbers or a model year......If you REALLY care, take the 10 minutes and check (the 10 minutes also takes into account the finding/making of a 5/16" square drive tool).

 

*Cough* Write-up? *Cough*

 

Both of the rods in that writeup are Forged PMR's, I make them! One is just more Crudely done, and less finished than the other! I would agree the Crude lookin one, (the one with the line goin down the side of the shank) is probably stronger. PMR Rods as You guys know them, (the nice one on top) can be made MUCH stronger, but that all depends what international wants too pay!

 

Umm....

One is a Powered Metal Rod. (PMR)

The other is a Forged Rod. (NOT PMR)

They ARE both Rods...

 

They are both forged! One is just more refined. The pretty one is forged a little differently. (actually better) The crude looking one, although "stonger" (which depends on material PM) is made with crude methods! I make these everyday! (Well not the 7.3ltr anymore) Again The Pretty one can be as tough as any, it depends what the customer is willing too pay! An example= The same rods used in a ford V6 (cant remember the exact engine right now) also go in a v10 or 12 (Idont remember, as I am not on that program anymore) aston martin. The difference is material. The astons are probably 3X's stronger, but are identical in everyother way.

 

WOW dude....

PMR: Powdered Metal. Stamped, powdered metal.
Forged: FORGED Steel. Cast in a forge.

Do I need to clarify the difference? ITS THE TYPE OF METAL. Powered Metal vs. Forged. They are not made the same way, because they are made with different metals. Clearly not identical, put together differently, made diffferently, with different metals. I have no doubt you make aftermarket or rods for later engines... but the ones in the 7.3 are not the same, at all.

 

Ok Dude. .

 

Actually, 2006lariat IS correct on some counts. Powdered metal rods (also called "sinter-forged") ARE forged.

Basically, it boils down to whether or not the metal is heated to it's absolute melting point or not.

"Forged" rods are poured into a cast as a liquid and then pressed using several thousand pounds. They are then cooled as a solid, forged piece of steel.

The powdered metal rods are constructed using fine metal powder and heated just enough to allow the particles to fuse together.

Yes, powdered metal rods ARE stronger and superior in many ways to their "forged" counterparts.....however, they are typically more brittle. This is why tuning plays a major part in how durable the PMRs are. Higher peak cylinder pressures can shatter the brittle rods that the more pliable "forged" rods can soak up for many more cycles.

 

I guess I may elaborate a little more.

I wouldn't call one process more "refined" than another. The forging process is a good bit different, but what happens to the connecting rod AFTER forging is quite different.

The "forged" rods are cast as two pieces. The main beam is produced separately from the cap of the "big end". The two halves of the big end are mated together (using a machining process), the rod bolts installed and torqued, the bore is machined, and then honed. At this point, the cap and the rod are a matched set. Then it's back apart to install in the engine. While it is possible to bolt another rod's cap on any of the other rods (and there will be little to no indication that it is incorrect), it is very possible to end up with journal clearances that are too tight, too loose, or just a bit off-center. The "forged" rods take a lot more machining to be correctly fit to a crankshaft journal.

The powdered metal rods are forged as one piece. Both ends of the rod are cast into the forging. The big end is machined and honed, bolt holes are drilled and tapped, and then the "big end" is broken in half. There is no way to install another rod's cap because the rough surface created by the break is privy ONLY to that connecting rod. It will be glaringly obvious that the wrong cap was installed on any particular connecting rod.

In addition, assembly of the engine is faster with powdered metal connecting rods (or ANY rod for that matter that uses capscrews instead of studs and nuts) because no assembly tools are required to keep the studs from nicking the crankshaft when the piston/rod assemblies are installed in the block.

By saving tons of time and machining processes involved in "forged" rods, the automaker (or engine maker in this case) can cut costs and production times while still offering a product that will operate as originally designed for the purpose for which it was meant.

 

So if you have a 2001 how do you know which rods you have?