powder forged rods
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
I just don't like the idea of taking metal powder, filling a mold and then under pressure and heat cooking it into a forging.
It might be strong, I don't know but the idea scares me.
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
LT1 and up uses powder machined rods, they are actually pretty nice. Easy to match from factory (you basically put the desired amount / grams of pwoder into the mold and forge the rod), they are said to be stronger than pink rods but don't drop them, they easily crack that way.
Team Owner
Joined: Jul 2004
Posts: 40,380
Likes: 789
From: Redondo Beach, California
I don't know very much about metallurgy; maybe enough to form erronious notions. I would think that the absolute most strongest rod would be a rod that was essentially a giant homogeneous perfect crystal. I would think that a powder rod, with the powder particles creating many small boundary layers, would not be the absolute strongest. If fact, I would think, notionally, that a powder rod would be succeptible to fracturing. What are the reasons that someone would make powder based rods anyhow? Maybe the powder based rods absorb piston shocks (compression) a little better than other techologies. But notionally, for the pull away forces, doesn't seem like they'd be that strong.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
To me it is like grains of sand glued together. You can make consistent rods in both shape and weight with no wasted material but there are many grain boundaries.
Ford seems to be able to fracture the parting line between the rod and cap with accuracy and they then stick the fractured surfaces back together with bolts.
I too like the idea of taking a big chunk of hot steel and punch a rod out with a large press and mold. You get consistent flow lines of material
Ford seems to be able to fracture the parting line between the rod and cap with accuracy and they then stick the fractured surfaces back together with bolts.
I too like the idea of taking a big chunk of hot steel and punch a rod out with a large press and mold. You get consistent flow lines of material
Thread Starter
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
howards is bragging them up pretty good with the arp 2000
215psi bolts 650 hp with a set of 245psi bolts 850hp these are
probably a few seconds at a time drag racing ratings. I have a
set of eagle H beam rods rated at 700 hp but they are heavy.
215psi bolts 650 hp with a set of 245psi bolts 850hp these are
probably a few seconds at a time drag racing ratings. I have a
set of eagle H beam rods rated at 700 hp but they are heavy.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
We have observed Powder Metal rods from late LT1/LT4/HD truck motors with cracks on the cap. Better than Pink Rods my BEHIND! Heck! I wont even put Pink Rods back into a LT-1 or 302 Z/28 motor, those blocks are too hard to find today. Go with Crower Sportsman or Manley Sportmaster rods STAY AWAY FROM Hi-Tech!
Thread Starter
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
I have been looking at crower and manley for awhile wanting a lighter
but strong rod, they both have the answer its just a matter of
opening the wallet up wide enough and selling off the eagle rods.
but strong rod, they both have the answer its just a matter of
opening the wallet up wide enough and selling off the eagle rods.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
To me it is like grains of sand glued together. You can make consistent rods in both shape and weight with no wasted material but there are many grain boundaries.
Ford seems to be able to fracture the parting line between the rod and cap with accuracy and they then stick the fractured surfaces back together with bolts.
I too like the idea of taking a big chunk of hot steel and punch a rod out with a large press and mold. You get consistent flow lines of material
Ford seems to be able to fracture the parting line between the rod and cap with accuracy and they then stick the fractured surfaces back together with bolts.
I too like the idea of taking a big chunk of hot steel and punch a rod out with a large press and mold. You get consistent flow lines of material
Splitting the cap by cracking is major reason why a lot of oem rods are now powder machined since it saves on expensive machining time and the cracked parts fit perfectly together, and the rough mating part positivly alignes the 2 pieces..
The wrought iron forging industry has since developed a crackable forged carbon steel to regain some of the market taken by the PM industry
an interesting read:
http://www.metal-powder.net/business...ess_jun05.html
Last edited by Twin_Turbo; Dec 18, 2006 at 10:20 AM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Powdered metal (PM) technology has come a long way. As initially formed, PM parts are about 99% the density of poured steel; then they get hot forged (or cold forged) and increase in strength considerably. The advantage of PM is that they will not have the internal flaws that poured parts can have. That is usually what causes rod failures...not overstressing (unless you've selected the wrong parts).
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Not all PM rods use fractured caps.
Those that do require different methodology to RE-size big end ... requires rod bearing with larger OD. Many shops won't mess with fractured cap rods.
Those that do require different methodology to RE-size big end ... requires rod bearing with larger OD. Many shops won't mess with fractured cap rods.
Le Mans Master
Joined: Mar 2004
Posts: 7,477
Likes: 1,495
From: Little Rock AR
Hard to argue with an inexpensive part that works as intended.-Mark.
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
It's not like sand held together, well it's at first when they make the preliminary shape, a green compact that is sintered into a briquette. This is then hot forged to the final shape. And last it goes through a time/heat controlled cycle in a sinter oven. You know how sintering works right, where all the grains melt together, the amount of fusing can be controlled in the sinter oven w/ the heat/time control. This also removes most of the crystalline structure faults.
Splitting the cap by cracking is major reason why a lot of oem rods are now powder machined since it saves on expensive machining time and the cracked parts fit perfectly together, and the rough mating part positivly alignes the 2 pieces..
The wrought iron forging industry has since developed a crackable forged carbon steel to regain some of the market taken by the PM industry
an interesting read:
http://www.metal-powder.net/business...ess_jun05.html
Splitting the cap by cracking is major reason why a lot of oem rods are now powder machined since it saves on expensive machining time and the cracked parts fit perfectly together, and the rough mating part positivly alignes the 2 pieces..
The wrought iron forging industry has since developed a crackable forged carbon steel to regain some of the market taken by the PM industry
an interesting read:
http://www.metal-powder.net/business...ess_jun05.html
I particularly liked the last paragraph...
"To sum up, it appears that the AISI's case against powder-forged connecting rods is in tatters. It seems unfortunate that the Bar and Rod Market Development Group chose the approach of an academic study to promote the use of drop-forged steel con-rods. Arguments based on assumptions that might be passable in academic circles do not always hold up in the real world of commercial manufacturing. In the present case it seems the AISI has gone public with a conclusion that is essentially devoid of substance."
I find this all the time in "Materials Science" where I now work.
Re-sizing would be an issue for me. The cost could turn them into a "throw-away" part. Don't like that concept.
