Cast VS Forged (now with more pics!)

I didn't take these pics, but I dug them up from my external HD last night for someone and thought you guys would enjoy them.

They are from 2001 or so. A guy on another board I post on owns a machine shop in Maryland and he wanted to demonstrate how strong a forged crank really was.


These are the pics he took as he did his testing.

He starts with a cast BBC crank.
You can see that after being tossed from atop a dumpster, the crank is no more.
He then moved on to a forged BBC crank.
That block of cement didnt stand a chance!
He was determined to break it, so he put it in the press.
I dont remember the number, and can't read the gauge well, but there were literally TONS of force on it.

And it never broke, and is now a showpiece in his shop.



CAST











FORGED

 

Just wondering compairing steel vs steel or C.I vs steel ?

 

I drop old cams on the concrete before I throw tham away. The smaller pieces fit in the metal recycling can easier. It is amazing how easy it is to break cast iron yet it will run hundreds of thousands of miles if used in it's designed intent.

Tom

 

Guessing CI. Don't remember for sure though... it was 7 yrs ago

 

Excellent example of crude stress testing. Now you understand why (read my posts on cast vs forged) I am so anti cast iron being used for other highly stressed parts like front axels, steering arms etc. I agree with 39 Delux, cast iron used in the appropriate manner/design is fine, and it's a much cheaper alternative than forged.
And there's the rub, because it's cheap to manufacture some idiots will made critically stressed parts (normally the province of forgings) from C.I. Sure the price is right, but it's your life on the line.

 

that test dont mean shit to me. That cast crank is under a force of gravity before it hits the ground. Idealy there is only a torque exerted on crants.