Im not an egnine specialist or anything but I had an idea.......Maybe it was an aluminum ALLOY? I dunno maybe im stupid but anymore they use a lot of mixed metals? Just my thoughts. How's everyones Raptors running by the way? =-)

 

why would drag cars have aluminum engine parts if they have a short life span and they are weak? if aluminum has a short life span to begin with, why would they put them in a car that can break metal rods? and you said that they put them in drag cars because they stretch????? i know for a fact that the yamaha YZ426 uses an aluminum rod. and by the way, i said an aluminum alloy a few posts ago. not pure beer-can aluminum. sheesh.

 

The crank is not aluminum, period. Not an aluminum "alloy", not titanium, not carbon fiber, nor Kevlar... It is either cast iron or steel.

Rods can be aluminum, but typically not in production engines (except some B&S (and probably other) lawnmower engines). I don't have the specifications in front of me, but I can virtually guarantee you that the Raptor doesn't include an aluminum rod, and I'm fairly certain the YZ-F does not either...

Serious drag race engines are stripped down and at minimum, inspected between nearly every run. That's why they can get away with exotic materials, but you won't find any aluminum crankshafts there either. Drag race engines IN NO WAY translate into what is practical for an everyday production engine.

Tell me, what do you think they are mixing with the aluminum to make this "alloy" that is lightweight, yet strong enough for a crankshaft, and if it's strong enough for the crank, why not the cam, rockers, and valves? Have they figured out something that no one else in the industrialized world has been able to accomplish?

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Now (sarcasm aside), help me out fellow techies... If I remember correcly, doesn't Yamaha claim they lightened the crank by using a "web" design vs the traditional "radial" design - or something to that effect? Can't find the info, but I do remember something along those lines....

 

i just emailed yamaha about the material the crank is made of. i'll copy and paste the reply

 

Here ya go....

Original post by "DesertRaptor"

The Raptor piston is made from 4032 high silicon alloy. 4032 is a aluminum/copper alloy, (mix). It has low thermal expansion, and contraction properties.
This means you can have tighter piston to wall clearance, thus more power.
The crankshaft and connecting rod are made from
4340 chromoly steel forgings. 4340 is a type of stainless steel. It is very tough, and extremely wear resistant under very high temperature.

 

yamahagye,
you seem pretty...mmh DUH! Can't find a way to say it.
Not to flame or whatsoever, but I personally would rather believe people on a forum rather than an official web page.
No way (absolutely NO WAY) a crankshaft can be made of aluminium, neither do the rods.
They are steel. Period. Because aluminium distorts to much. You would bend the crank soooo fast. Rods can be aluminium, but you'll have to change them real often. The lightest rods are made of titanium, but the Raptor doesn't have them (way to expensive).

Just curious. Why did you start a post and blast people who say you're wrong?

This is a question for the knowledgeable here. Of what are Formula1 (or CART, for that matter) crankshafts? I guess rods are titanium...but I have no idea about the cranks.
Thanks (no one tell me the F1 cranks are aluminium!!)

 

GIVE IT A FRIGGIN' REST, YAMAHAGYE!!!!!!!

 

I just read this topic and connont stop laughing! An aluminum crank! Thats great, give this guy the $10,000 dollars.

 

settle this once and for all, just took off my top end TODAY to send to trinity,

the rod is NOT aluminum, the piston like all is! rocker cover head and cylinder are all cast aluminum (had to have rocker cover welded)

 

I thought I'd come back on here after so long and apologize for any and all of my early posts with false information. I have grown up alot in maturity and knowledge of atv's since I first started posting. This post is reguarding all early posts of mine and not just this one.

JaMeS

P.S. I will admit that I was wrong about the crankshaft and rod being made of aluminum