Aluminum Con Rods
11-21-2009, 11:54 AM
#1
Tour de Franzia
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Aluminum Con Rods
NOTE: I have divorced this discussion about aluminum rods from this thread: https://www.miataturbo.net/forum/t40553/
-Perez
-Perez
Last edited by Joe Perez; 11-23-2009 at 05:23 PM.
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11-21-2009, 05:02 PM
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Boost Pope
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You can see tooling marks on some of these American-made units, for example: Aluminum Connecting Rods
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11-21-2009, 07:08 PM
#7
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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
You can see tooling marks on some of these American-made units, for example: Aluminum Connecting Rods
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11-21-2009, 11:34 PM
#10
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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.
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11-22-2009, 07:57 AM
#11
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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?
Would somebody considder those billet rods?
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11-22-2009, 03:27 PM
#12
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.
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11-23-2009, 04:14 PM
#14
(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.
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; 11-23-2009 at 09:19 PM.
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11-23-2009, 09:14 PM
#20
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.
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.
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