any one in NZ make billet cranks for 3sgte /ge

[MAGN1T]

This is a good how to: Cast Vs. Forged

.

Here's a better one.

http://www.popularhotrodding.com/tech/0 ... index.html

It's still a magazine article though but got better references, not just some journo who likes to use big words to confuse everyone,
Forged cranks don't have parting lines nor do they have numbers and letters cast into them. Any numbers or letters are either pressed in or engraved.(TRD)
The narrow/wide parting line is the difference between a cast iron and cast steel crank.
Nor can you tell between cast and forged with the "ring" test, that's how you tell a cracked crank (just as a cracked bell won't ring).

Unfortunately the internet seems to consist of the bullshitters bullshitting the other bullshitters with everyone claiming to be some sort of expert after 2 minutes on google despite having little or no practical experience. There's more misinformation than fact, especially with US based sites.

Steve

[allencr]

Forged cranks don't have parting lines...
The narrow/wide parting line is the difference between a cast iron and cast steel crank.

This man, he doesn't.

X2

[MAGN1T]

Car modification.....no different from religion....it's a cult with the blind leading the blind (usually someone who's selling something).
Stupitidy seems to be contageous, people inherit it from others when all they need to do is to open their eyes.
Actually from an american , it's to be expected.

So.......take a look at a 4AG crank, that's easy, there's a photo above on page 1. Does it have a wide parting line? What? never looked?
How about a 1JZ/2JZ?
How about a RB30?
How about a 4G63/4G93/any other Mitsi crank?
How about a 2L/3L?
They're all the same.
How many of them are forged?
Answer.....Zero.
So, most people just believe what they're told because they can't figure it out for themselves.


Well if you've got no idea what you've got to start with, how are you supposed to know whether or not you've wasted money on an upgrade/ downgrade.

Steve

[iOnic]

WTF did I just read?

[Mr Revhead]

MAGN1T

You have been warned before about posting BS in tech threads.

STOP

I have yet to see any Toyota crank that was not forged.

[Grrrrrrr!]

How do you know that it's forged? Not doubting you just want to know how you can tell, besides no casting marks

Easiest truely reliable way to tell would be to polish it, etch it and stick it under a microscope and look at the grain shape. Wide vs narrow parting line could come down to the forging tools and process, and if its been polished or shotpeened you'll never know by just looking.

[RomanV]

MAGN1T

You have been warned before about posting BS in tech threads.

STOP

What has he said in this thread that is BS?

I think Magn1t is one of the most interesting posters in the tech forum.

If you think about what he says for long enough...

It just.

about.

makes.

sense.

I have yet to see any Toyota crank that was not forged.

How do you know that the cranks that you saw were forged?

What were the indicators of this process, vs casting?

If you havent seen a Toyota cast crank, then how do you know what it would look like if you did?

Do you consider your emperical evidence of having not seen a cast Toyota crank yourself, evidence that there is no such thing?

I agree that a lot of "internet facts" could do with challenging, and it's healthy to reevaluate your ideas, even if you end up at the same conclusion.

http://www.youtube.com/watch?v=T69TOuqaqXI

[MAGN1T]

MAGN1T

You have been warned before about posting BS in tech threads.

STOP

I have yet to see any Toyota crank that was not forged.

So based on your logic, there's no market and never will be a market for TRD cranks because although they're forged, so are the factory ones?

2 Toyota cranks, 2 non toyota cranks.
Which ones are forged ?
[img=http://img691.imageshack.us/img691/1911/dscf0044z.th.jpg]

[img=http://img859.imageshack.us/img859/9278/dscf0047.jpg]

[img=http://img844.imageshack.us/img844/9638/dscf0055f.jpg]

[img=http://img24.imageshack.us/img24/7096/dscf0034ri.jpg]





Steve

[Dell'Orto]

1st and last are cast? (guessing here)

[deaf_rattle]

dont crank shafts cause bhgs? im yet to see a car suffer a bhg without a crank shaft

[Celica RA45]

the 1st 3 are forged going by the wide join mark the last 1 i would say is cast
and back on subject 18r crank is cast 18rg is forged well in toyotas std anyway

[RomanV]

You can talk femto seconds if you want, it doesn't change the fact that at X rpm you have Y time. If you are spending more of that time at the top and bottom you have to move faster on average in between to still complete the movements in the same amount of time.

Imagine for a second that the piston had an exactly linear speed up and down, through the whole stroke.

The piston gets to TDC, and instantaneously changes direction.

If the linear piston speed is 10, at TDC it's instantly changing from a speed of +10 to -10.

IF you plotted a time vs distance from BDC it would look like this:



When you use longer rods to change the rod ratio, time that the piston has to decellerate and start moving in the opposite direction increases.

The change in direction is presumably the most destructive force on a piston, hence a longer rod allowing higher rpms.

[Mr Revhead]

Have a look at a Toyota crank
You cannot see "fluid" markings formed if molten metal is poured into a mould. As in a grain of flowing metal, if you get what I mean.
What you see is a hunk of heated metal that's been pressed (forged!) into a mould. Have a look at the markings, you can quite clearly see marks that cannot be formed by a fluid being poured then cooling.
Can I explain it fluently? No. Can I point it out to you in person? Damn straight I can.
How did I learn? By being taught the visual difference from a bloody good engine builder.

I am not going to pretend I can see enough detail in all those pics to say what they are.

I would not be at all surprised to find that 90% or more of Japanese car engines built in my lifetime have forged cranks.

The problem with MAGN1T is 99% of what he posts is either pure BS or based around BS. It wouldn't be a problem but he consistently posts incorrect and misleading info. Sure you can post incorrect info and be corrected, it's part of learning and what forums are about. He doesn't learn. Instead he starts insulting everyone else claiming he is correct and everyone else is wrong. He has been officially warned about it before.

This quote says it all really:

So.......take a look at a 4AG crank, that's easy, there's a photo above on page 1. Does it have a wide parting line? What? never looked?
How about a 1JZ/2JZ?
How about a RB30?
How about a 4G63/4G93/any other Mitsi crank?
How about a 2L/3L?
They're all the same.
How many of them are forged?
Answer.....Zero.

Steve

[levinguy]

I agree that a lot of "internet facts" could do with challenging, and it's healthy to reevaluate your ideas, even if you end up at the same conclusion.

http://www.youtube.com/watch?v=T69TOuqaqXI

please post in smartphone thread.

[RomanV]

How do you know that it's forged? Not doubting you just want to know how you can tell, besides no casting marks

Easiest truely reliable way to tell would be to polish it, etch it and stick it under a microscope and look at the grain shape. Wide vs narrow parting line could come down to the forging tools and process, and if its been polished or shotpeened you'll never know by just looking.

So, for interest's sake, what would be involved to get a crank tested in this way, and prove it definitively one way or the other?

Take a crank to a... blacksmith? scientist? alchemist?

[Malcolm]

I could probably get it checked, I'm good friends with a few people who work in the chemicals and materials labs at uni

[Grrrrrrr!]

Metallurgist. The actual process isn't that hard. (cut a sample, mount it, polish it then etch with Nital) Had to do it for a lab in 1st year of engineering degree, its knowing what you are looking at that is the hard bit that takes a bit of experience. From what I remember a forged crank would have smaller grains than cast and they would be elongated in the direction they flowed during the forging process. Might need to polish/etch several faces to get a good idea of the grain shape. A metallurgist would probably be able to tell by looking at the outside of the crank so long as it hadn't been peened/polished/machined.

[MAGN1T]

How did I learn? By being taught the visual difference from a bloody good engine builder.

I am not going to pretend I can see enough detail in all those pics to say what they are.

I would not be at all surprised to find that 90% or more of Japanese car engines built in my lifetime have forged cranks.

Yes you ARE correct.

The difference in the parting line is the difference between a STEEL crank and an IRON crank.

As per my first post on the subject, the chineese whispers mix things up .

The word IRON gets associated with the word CAST while the word STEEL gets associated with the word FORGED when in fact it's CAST STEEL.

Anyway, university, that's all about learning and science and learning about people misleading you, you'd need to examine a REAL forged crank for comparison.

Steve

[Malcolm]

Anyway, university, that's all about learning and science and learning about people misleading you, you'd need to examine a REAL forged crank for comparison.

Steve

Right. You're telling me an experienced metallurgist can't tell how a piece of metal has been formed by looking at grain structures under a microscope? They need some other genius to stand next to them with a "real" forged item for comparison so they can go back and forth to decide if they're the same?

I have no issue with people being skeptical, but being needlessly skeptical of well understood science is just ignorance.

[Mr Revhead]

There's cast iron, there's cast steel , there's forged steel, there's billet.
Most modern jap cranks are cast steel. most older american V8 cranks are cast iron.

Unfortunately when the word "steel" is used, uneducated people relate "steel" with "forged" when it's not the case.
Usually with americans (because most of them are reeeeallly thick).
The above photo, stock crank is cast, the TRD is forged. There's a very obvious difference.

A forging will tend to bend before it breaks, as conrods always do. A casting will crack before it bends, as cast cranks do.


Steve

Your first post.
the part in bold is wrong. That stock crank is most definitely a forged steel crank.

yes there is a difference.
A stock crank is not made for the same thing as a race crank.
therefore the steel used can be different. the shape can be different.
The final machining can be different.
All of those things will make it appear quite different.