Are 4AGZE cranks forged steel or cast?

[toddw]

I have done a huge amount of research lately regarding this topic and have found a lot of differing opinions. From well respected tech. people like Phil Bradshore who says that they are to forums in the US saying that all 4AGE cranks are forged(which I know is not true). Can anyone shed some light on this as I have justpurchased a 4AGZE which will be the basis of a high comp. atmo. engine. It would be good to know once and for all.

[Ben Wilson]

4AGE cranks are forged(which I know is not true).

I'm pretty sure they all are.

The only real difference between a ZE and a later model NA engine is the low compression pistons and the injectors.

[Rallystanza]

Everything I have read and seen has led me to believe that ALL 4A cranks are Forged Steel.

[oldcorollas]

easy way to check is to cut one up polish and then etch with a macro-etching solution, and you should see the forging grain lines...
cast won't have this.

[psychofox]

ALL 4A cranks that feature 42mm big end rod journals are the same. They have the same part numbers, and of all the 16V, 20V, GZEs I have ever taken apart, they are all identical.

I am personally unsure if they are Forged or not, but according to Richard White - who wrote up a great analysis of the Cranks and Flywheels - he believes that the factory item is forged steel. I know that TRD make a forged steel crank for the Atlantic spec motors, and Tomei make a forged crank as well.

The article on Club4AG is here:

http://www.club4ag.com/faq%20and%20t...0Analysis.html

[toddw]

That is an awsome article which seems to have a awful amount of info. The auther seems to know his stuff and he states that they are all Forged - so there you go. Thanks for your help. It makes me feel a little better when I give my 4age a big rev.

Cheers

[roadsailing]

in my opinion the smallport cranks are forged, as they look like they are.

note the bit of the crank in the photo, and how wide it is. this (if i remember from uni correctly) is a sure sign of forging, if the crankshaft had been cast, the flash area would be much smaller, as the moulding cores fit together a lot closer than forging dies.



this isnt a photo of mine, but looks exactly the same as mine.

i dont remember what my 4AC one looked like, anyone got a spare? i do have access to a FWD bluetop engine, so maybeye that has a cast crank.

i'm going on the assumption they are forged, as i want lots of revs out of my motor.

[feral4mr2]

easy way to check is to cut one up polish and then etch with a macro-etching solution, and you should see the forging grain lines...
cast won't have this.

i see another cut and analysis thread comeing up... who has a old crank?

[Ben Wilson]

this isnt a photo of mine, but looks exactly the same as mine.

That's not a 4AG crank, the 4AG cranks has 8 flywheel bolts.

[roadsailing]

oops, didnt notice that.

it is actually a 7A crank (got the pic off a page about 4AGE cranks), but the early 4AGEs did have 6 bolt flywheels, as per the 4AC slime they emerged from.

in any case, it illustrates the point i was trying to get accross, thats what my smallport crank looks like.

only i thought 7A cranks were cast?????

the page is an interesting read, in any case

http://www.club4ag.com/faq%20and%20t...0Analysis.html

[Mos]

the early 4AGEs did have 6 bolt flywheels, as per the 4AC slime they emerged from.

Which ones were 6 bolt? I had a JDM AE86 8 bolt one which I thought would have been pretty early?

Mos.

[Jorrs]

how about the Silvertops/blacktops ?

[oldcorollas]

i didn't real all of that page, but some of it is wrong
still, lots pretty pictures...
this is not the 4AG crank... (damn non-linking.. grr)

[Rallystanza]

I Have a old banana'd crank that I am willing to sacrifice for someone to analise...Its the early 40mm big end 18mm small end crank, 8 bolt to flywheel.

[terryo]

all the 4AG cranks I've ever seen are definitely forged. I've seen early 7A cranks that are forged, but the later ones are cast-I dont know when the change occurred. The width of the parting line where the flashing is ground off, is a definite sign on almost any crank. I've know idea where the forged 6 bolt 4AG crank came from, maybe an early auto??