So.. you want your built EJ257 to last? Look here..
 

Hi all,

After hearing about so many EJ257's that have popped, then people rebuilding them with decent pistons and rods, and then having them pop again, you'd probably think they're junk and you have to spend $5k reinforcing the block with liners and close decking to make it handle power.

Well I'm not going to comment on that, but I always found it amazing that Cosworth's crate motors have a stock block, and there are plenty of NASIOC anecdotes of them making plenty of power and doing heaps of miles at the same time.. one guy claimed over 100k miles, and a few are saying they've clicked over 50-60k miles without a hiccup.

[B]To put it simply..[/B]


Cosworth torque plate hone the blocks with Cosworth gaskets and head studs in place, and apparently [B]the block is heated up to operating temperature too prior to honing[/B].. once they do this, they apparently last.

This is important because the bores are out of round from the factory.

Stock bore with torque plate not torqued into place

[img]http://cosworthusa.com/store/pc/catalog/subblock2.jpg[/img]

Torque plate done up as per head stud torque settings.

[img]http://cosworthusa.com/store/pc/catalog/subblock3.jpg[/img]

Out of round by .0023!!

So, if your piston needs .003 of piston to wall clearance, you're gonna be in trouble if you hone or bore without the torque plates. Not only will it do a ring land or scuff a bore once the piston hits that tight part of the bore, but plastic deformation of the block can occur if its constantly pressed and rubbed in that tight spot by the forged piston.. and this can cause a crack.

If you're getting a 257 built, ask the workshop to torque plate hone. There is one workshop I know of that does this and they've had a lower failure rate than some of the other workshops as far as I know.

If you wanna be baller, contact Cosworth and buy their torque plates.. they sell them to engine builders (not cheap!).

So I'll leave it right there... thoughts and comments are welcome.

Its funny Joe cos I reckon with sensible mods and a decent tune they are not as bad as everyone thinks, I've got 90K km on the clock with around 290 or so at the hubs and it was done almost from new, its not like I drive like American Dave:). Guess it depends how much power you are chasing
Al

300-320 would be about the limit from what I've seen, but they seem to make more torque than EJ207's with 100HP more!

Just depends what you're chasing.. I love driving my wife's MY09, its effortless with the EJ25 and for a quick daily drive its perfect.

[QUOTE=stinga;503615]Its funny Joe cos I reckon with sensible mods and a decent tune they are not as bad as everyone thinks, I've got 90K km on the clock with around 290 or so at the hubs and it was done almost from new, its not like I drive like American Dave:). Guess it depends how much power you are chasing
Al[/QUOTE]

oh thats harsh Al :D

Yup this is how my engine from tony knight was done... :D

Agreed Joe, certainly prefer the modded 257 over the modded bug 205 around town.
AMD, I ain't the one with a slush box bro:)

[QUOTE=BALISTC;503609]
If you're getting a 257 built, ask the workshop to torque plate hone. There is one workshop I know of that does this and they've had a lower failure rate than some of the other workshops as far as I know.
[/QUOTE]

Mine had new liners and torque plate bore and hone............still popped and I beleive has popped again under the new owner.

[QUOTE=PIGSTi;503632]Mine had new liners and torque plate bore and hone............still popped and I beleive has popped again under the new owner.[/QUOTE]


Yes it has, engines coming out again soon

I said lower failure rate.. not nil :)

[QUOTE=PIGSTi;503632]Mine had new liners and torque plate bore and hone............still popped and I beleive has popped again under the new owner.[/QUOTE]

No matter what you do to the motor... Can't help poor driving ability! ;)

Stick to the Holden Combo Cuz! :p