Notices
Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by: KPower

Aluminum Con Rods

Thread Tools
 
Search this Thread
 
Old Nov 21, 2009 | 11:54 AM
  #1  
hustler's Avatar
Thread Starter
Tour de Franzia
iTrader: (6)
 
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
Default Aluminum Con Rods

NOTE: I have divorced this discussion about aluminum rods from this thread: https://www.miataturbo.net/forum/t40553/
-Perez


Last edited by Joe Perez; Nov 23, 2009 at 05:23 PM.
Old Nov 21, 2009 | 03:06 PM
  #2  
chance91's Avatar
Senior Member
iTrader: (3)
 
Joined: May 2008
Posts: 533
Total Cats: 3
From: Fargo, ND
Default

Originally Posted by hustler
Chinese, right? That's the problems with the Ingot I'm talking about, I think.
Bad heat treating from the get-go, perhaps.
Old Nov 21, 2009 | 03:27 PM
  #3  
curly's Avatar
Cpt. Slow
iTrader: (25)
 
Joined: Oct 2005
Posts: 15,168
Total Cats: 1,393
From: Oregon City, OR
Default

That doesn't appear to be heat treated at all, solid billet pieces, you can still see tool marks in the center.
Old Nov 21, 2009 | 04:07 PM
  #4  
y8s's Avatar
y8s
DEI liberal femininity
iTrader: (8)
 
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
Default

machined aluminum rods? not even polished/blasted to remove the maching marks? smells like a rebuild waiting to happen.
Old Nov 21, 2009 | 04:46 PM
  #5  
cueball1's Avatar
Elite Member
iTrader: (13)
 
Joined: Nov 2006
Posts: 3,875
Total Cats: 2
From: Tigard, Oregon
Default

That split rod might make a good model for the MT.net t-shirts!
Old Nov 21, 2009 | 05:02 PM
  #6  
Joe Perez's Avatar
Boost Pope
iTrader: (8)
 
Joined: Sep 2005
Posts: 34,381
Total Cats: 7,504
From: Chicago. (The less-murder part.)
Default

Originally Posted by y8s
machined aluminum rods? not even polished/blasted to remove the maching marks? smells like a rebuild waiting to happen.
They're somewhat popular with the guys running 500 hp / liter. Lighter weight than steel = less inertial strain at high RPM.

You can see tooling marks on some of these American-made units, for example: Aluminum Connecting Rods
Old Nov 21, 2009 | 07:08 PM
  #7  
sixshooter's Avatar
Moderator
iTrader: (12)
 
Joined: Nov 2008
Posts: 22,155
Total Cats: 3,536
From: Tampa, Florida
Default

Originally Posted by Joe Perez
They're somewhat popular with the guys running 500 hp / liter. Lighter weight than steel = less inertial strain at high RPM.

You can see tooling marks on some of these American-made units, for example: Aluminum Connecting Rods
Aw, come on! Those in your link are obviously a significantly higher grade of machining and finishing. The one in Hustler's pic looks like someone did it on a cnc for a static display and somebody f'd up and actually used it. I bet there are some for sale on ebay somewhere just like them, though.
Old Nov 21, 2009 | 08:39 PM
  #8  
y8s's Avatar
y8s
DEI liberal femininity
iTrader: (8)
 
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
Default

^ what he said. rounded corners and I can't see machining marks very well.
Old Nov 21, 2009 | 09:03 PM
  #9  
hustler's Avatar
Thread Starter
Tour de Franzia
iTrader: (6)
 
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
Default

I believe that's a BME rod from an evo actually.
Old Nov 21, 2009 | 11:34 PM
  #10  
Joe Perez's Avatar
Boost Pope
iTrader: (8)
 
Joined: Sep 2005
Posts: 34,381
Total Cats: 7,504
From: Chicago. (The less-murder part.)
Default

Originally Posted by Halcyon
I'm waiting for the post to say a specific "made is China" rod is as good as or close to belfab or the like.
A specific "made in China" rod is not as good as (or close to) an M-tuned rod.



Originally Posted by y8s
^ what he said. rounded corners and I can't see machining marks very well.
Yeah, I'm looking at the BME website right now, and that one in Hustler's pic does look a lot like 'em. Same chamfer around the rod journal, same shape on the shaft, only difference is that the ones on the website appear to have been polished so you can't see the tool marks from the milling operation.



Thing is, and I admit that I'm no ME, but that sucker split right down the middle, through the most perfectly rounded parts of the assembly. To me, that screams "materials defect".


But we're threadjacking.
Old Nov 22, 2009 | 07:57 AM
  #11  
IHI's Avatar
IHI
Junior Member
 
Joined: Oct 2009
Posts: 200
Total Cats: 1
From: The Netherlands
Default

Wow... Those billet rods look cool! For $600 they are more expensive but they do offer a lot of weight savings.. The split one isn't what I'd like to see. No one can put a bend eagle or chinese rod in here (cheap H-beam).

Would somebody considder those billet rods?
Old Nov 22, 2009 | 03:27 PM
  #12  
chance91's Avatar
Senior Member
iTrader: (3)
 
Joined: May 2008
Posts: 533
Total Cats: 3
From: Fargo, ND
Default

Originally Posted by curly
That doesn't appear to be heat treated at all, solid billet pieces, you can still see tool marks in the center.

I was referring to Heat treating before the CNC process.

You have to heat treat the material at least once, sometimes several times, just to get it up to par for use. Of course, it's hard to say what caused the failure like that, but, to me, it looks like a flaw in the grain of the metal.
Old Nov 23, 2009 | 02:17 PM
  #13  
y8s's Avatar
y8s
DEI liberal femininity
iTrader: (8)
 
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
Default

i think it's high time the aluminum cnc rods BS ended. nobody here will ever buy them. and if they do, I'll make a hat out of fruit roll-ups and eat it.
Old Nov 23, 2009 | 04:14 PM
  #14  
miata2fast's Avatar
Elite Member
iTrader: (2)
 
Joined: Aug 2009
Posts: 3,145
Total Cats: 175
From: Dover, FL
Default

(Someone F'ed up there.

JE's are good stuff. They will spec out different grades of hardness to be used for different applications and power adders. When I told them that I was using nitrous, they speced an alloy specific to the demands that nitrous creates. Which is actually a little softer to have some "give" if I recall.

Edit. This post was originally in the JE vs Wisco vs Eagle vs Carrillo thread.)

BTW, back to the aluminum rods. Hustler's pic is not a BME rod. I have used them, and all of them have "BME" in the casting just like the photo in Joe Perez's pic.

Last edited by miata2fast; Nov 23, 2009 at 09:19 PM.
Old Nov 23, 2009 | 04:46 PM
  #15  
y8s's Avatar
y8s
DEI liberal femininity
iTrader: (8)
 
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
Default

Originally Posted by miata2fast
BTW, back to the aluminum rods. Hustler's pic is not a BME rod. I have used them, and all of them have "BME" in the casting just like the photo in Joe Perez's pic.

I think I found the problem.
Old Nov 23, 2009 | 06:18 PM
  #16  
sixshooter's Avatar
Moderator
iTrader: (12)
 
Joined: Nov 2008
Posts: 22,155
Total Cats: 3,536
From: Tampa, Florida
Default

Originally Posted by y8s
I think I found the problem.
"Hark! Hark!" harkened he.
Old Nov 23, 2009 | 06:28 PM
  #17  
Full_Tilt_Boogie's Avatar
Elite Member
iTrader: (1)
 
Joined: May 2009
Posts: 5,155
Total Cats: 409
From: Jacksonville, FL
Default

**** aluminum, its all about that titanium yo!




Now where's that money tree...
Old Nov 23, 2009 | 06:57 PM
  #18  
Joe Perez's Avatar
Boost Pope
iTrader: (8)
 
Joined: Sep 2005
Posts: 34,381
Total Cats: 7,504
From: Chicago. (The less-murder part.)
Default

Originally Posted by miata2fast
I have used them, and all of them have "BME" in the casting
Originally Posted by y8s
I think I found the problem.
Can not a forging process be made to leave a raised marking such as this?
Old Nov 23, 2009 | 07:25 PM
  #19  
neogenesis2004's Avatar
Elite Member
iTrader: (12)
 
Joined: Aug 2006
Posts: 4,413
Total Cats: 20
Default

Originally Posted by y8s
and if they do, I'll make a hat out of fruit roll-ups and eat it.
I will buy a set just to see this, but it has to be a real hat. Prepare for youtube video!
Old Nov 23, 2009 | 09:14 PM
  #20  
miata2fast's Avatar
Elite Member
iTrader: (2)
 
Joined: Aug 2009
Posts: 3,145
Total Cats: 175
From: Dover, FL
Default

There is an advantage to aluminum rods. They are certainly not used in road racing or street use, at least not much, but if you are drag racing, and have a huge turbo or shot of nitrous, they are spongy enough to soften the hit to the crankshaft and main caps. The only real downfall to them, is there is no way of knowing when they fail. X-raying them will not show fatigue areas in aluminum (unless something new is out there to test them). That is why you have to change them every so often (What I was told any way).

Also you are not supposed to downshift a motor with them, because they have very little tensile strength. Downshifting is not done in drag racing.



All times are GMT -4. The time now is 02:48 AM.