Toyspeed.org.nz Message Board

by **Celica RA45** » Sun Jun 26, 2011 4:48 pm

looking for any 1 here that knows where i can get a billet crank for a 3sge /gte that can handle high revs like 9500 plus
as the std toyota can not handle the revs ,as they seem to crack along the bigends

no grip · by **Akane** » Sun Jun 26, 2011 5:34 pm

Are you sure about this? Guys in the states making big numbers and revving past 9k still using the stock standard 5S / 3S crank, but balanced and treated.

If you still insist on having a billet crank, you might have to get one from JUN, afaik they're the only ones who makes cranks for the 3S.

by **KinLoud** » Sun Jun 26, 2011 5:59 pm

I know of a high revving 3sge - they used standard cranks...
They did have a problem with them cracking
BUT
The problem went away once they went back to a standard crank pulley rather than the lightweight aftermarket one they were using.
Seems that the crank needed the damping provided by the standard pulley.

by **Celica RA45** » Sun Jun 26, 2011 6:25 pm

im using std pulley and also tuffbond pulley made over here
also the crank has been on a diet with 2,5 kilos taken off it near counter weights
also running longer rods than std so i can rev it higher 1 set up is 146mm long and the other is 144.78 mm with the bigends ground down to 45mm to use mitsubishi rod bearings
the cracks are going along near the radius
i am wondering if a frequency is causing this to happen and most 3sge motors has a harmonics issue any way

by **strx7** » Sun Jun 26, 2011 7:05 pm

Celica RA45 wrote:i the crank has been on a diet with 2,5 kilos taken off it near counter weights

i would say that is the problem.......

by **Celica RA45** » Sun Jun 26, 2011 11:42 pm

most race cranks are lightened anyway and these were done by a motor sport person that does v8 and rb26 cranks etc and it was rebalanced ,shot peened etc and the radius wernt touched .we are thinking the std crank cant handle the revs .it has been a test mule motor so i could see how it went with different heads and cams etc ,this was after it raced for 2 years solid
also my other mate had his break and take out the block and it still had the rods and pistons attached when it let go at 9200 rpm,

by **strx7** » Mon Jun 27, 2011 7:48 am

Jeff @ Precision Engineering could make one.

by **Bazda** » Mon Jun 27, 2011 9:25 am

Lightening will cause them to crack. Happens in the 4A engines.

The counter weights are there for a reason. To counter act the harmonics and forces on the crank.

Even knife edging will make the crank weaker.

I would say this is your problem, get another crank, prepare it, dont take weight from it and see your results.

by **strx7** » Mon Jun 27, 2011 12:33 pm

Bazda wrote:
The counter weights are there for a reason. To counter act the harmonics and forces on the crank.

That was exactly what i was thinking.

by **CelicaGT8** » Mon Jun 27, 2011 6:59 pm

i rev to 8.5 in my gen 2 3sgte and its fine

by **iOnic** » Mon Jun 27, 2011 7:16 pm

Taking material off the crank then increasing rod length is what's causing them to crack. Regardless of who does it, machining them down = weakening. You'll always have a much shorter lifetime out of a lightened crank.

by **nzae86** » Mon Jun 27, 2011 7:18 pm

Here is a standard Toyota 4AG crank next to a TRD crank

The TRD crank has bigger counterweights than standard and weigh more,they are built like this to withstand the forces of high revs .

by **Bazda** » Mon Jun 27, 2011 7:21 pm

Thats exactly right.

Same as my dads cranks on his cosworth engine, they are custom made by cosworth and made beefy as hell so they can rev them to 10k all day long.

by **Flannelman** » Mon Jun 27, 2011 7:57 pm

Take the 3sge crank to a machine shop and get them to increase the radius. Reduce the journal size yet NOT create a sharp edge from the journal to the counterweights. The next problem is finding a berring for the new journal size. Also, watch as the radius may start to sqeeze into the berring contact area.

by **MAGN1T** » Mon Jun 27, 2011 9:03 pm

The TRD crank is forged, the stock one is cast = huge difference.

Steve

by **iOnic** » Mon Jun 27, 2011 9:09 pm

Stock 3s crank is forged.

by **strx7** » Mon Jun 27, 2011 9:12 pm

3sge/3sgte cranks are forged, 3sfe cranks are cast

by **iOnic** » Mon Jun 27, 2011 9:31 pm

Really? Never knew that. I dont pay much attention to FE's tbh

no grip · by **Akane** » Mon Jun 27, 2011 9:56 pm

iOnic wrote:Really? Never knew that. I dont pay much attention to FE's tbh

How dare you neglecting the 3S-FE's! :lol:

That TRD crank looks like the ones JUN has made for various engines too, big beefy counterweights.

by **MAGN1T** » Mon Jun 27, 2011 11:05 pm

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

Toyspeed.org.nz Message Board

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

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

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