what are the limits of a ej257 without linner problems?
thanks

 

How long is a piece of string

 

not sure about string at a guess double the length from one side to the middle

i have read 480ish? or is that a bit much?

 

oioi is this jaffa?

 

yes mate

 

In testing, Prodrive stated that the 2.5 lump is reliable to 340bhp.

Detination will occur past this without uprated internals!

 

SWEET. good to see your on here.

Hows the car going? Still got my turbo?

 

i will be using uprated internals

 

with the right internals, alot more than 480 is possible

 

so 450 every day wouldnt push it too much?

what are my options to make it stronger if i want more power in the future. sleaved?
cheers

 

 

Det will occur if you have a bad map/ bad fuel! It should say that the standard pistons are rubbish & the lands between the rings give up easily.

 

Should xbhp be fine is difficult to answer, but assuming the engine is built / mapped correctly and you have the right supporting ancillaries, then yes, 450bhp and applicable torque should be fine.

I have been running 500+ of each for the best part of 18 months but the car was spec'd for track and competition use. It has been very reliable during this period, which I hope will continue. This is on the standard casing and cylinders, albeit with some machining based mods to the block to assist head gasket / liner issues. Nothing is gauranteed though.

Several other methods exist around re-lining the block, but as of yet, nothing exists that I am completely sure is any more reliable than what I already have. These consist of a top hat liner design as well as a conventional liner.

The block is inherently flawed in design, as regards to using the same casing as the 2ltr, but upping the cylinder capacity to 2.5ltrs. This results in less space available for cylinder thickness and stability.

A couple of "other" solutions exist, but they involve machining the liners and fitting complete inserts to enable a more "closed deck" nature. One in particular has just been designed and released, which also takes the capacity up to 2.6ltrs. I am tempted to look at the latter during 2009.

You pay your money and take the risk...... because at this level of 500+ on a 2.5ltr, that is exactly what you will be doing. Nothing is absolute at this level and above, regardless of what people may lead you to believe.

Dependant on your use, it can get very very expensive at this level. Hence why not that many true 500+ 2.5ltr Subaru engines exist and continue to work without reliability issues.

 

Yep, the pistons are the weak point.

Detination , wrong wording!

 

This engine built by APi, is on a standard block.

https://www.scoobynet.com/trader-ann...ut-subaru.html

 

I would happily run 600bhp on my 2.5ltr lump without fear of trashing it

 

ya but yours has been fitted with thicker liners so in reallity shud take a lot more abuse than the original liners.

 

Have a read here tone
22B Bulletin Board: Will it last ?

 

Steve,
I would be happy to run 600+bhp on my block as well (with a suitably spec'd turbo)! My block spec has already ran a fair bit more than that for most of a Time Attack race season without any cylinder issues. Regardless of that, suggesting that there is no risk is being some what naive. Are you stating your engine is bullet proof at 600bhp then?

 

Sorry for the hijack but what kind of power could a standard STI 2.0 block with uprated forged internals take? Would 450 be safe?

 

Shaun

I'm pretty sure unless I miss a gear my engine is bullet proof for 600bhp I know the rods I have just added are to cope with over 600bhp. I will ask Chy what he thinks the block can take but I think 600bhp all day

 

Steve,
That's quite a statement saying it is "bullet proof".

Scooby-doo97,
Assuming all things equal... no problem.

 

Thank you Shaun.

 

Are there more 2.5 failers with bolt on turbos then twisted set ups due to having bolts ons running at highter pressure?

 

I'm sure I have no problem with Chy's block, if it were to fail I'm sure it will be more down to my incompetance

 

Steve,
What does Chy charge for a fully built bottom end and what does he fully expects is it's safe limit for track use?

Cylinder pressure is an issue, but so is det and the affect of det when experiencing headgasket issues. I have seen det start to eat away the top of the liner.

Keeping the torque at sensible levels should see you OK, assuming everything else being equal.

It also has a lot to do with your intended use..... the harder you push the engine, in say track conditions, the more chance you have of finding a weakness.

 

I have yet to see a 2.5lt block fail running a bolt on, all the ones I've seen have been on rotated.

 

Std Ej257 engine, rods and pistons have been run over 400 bhp / 400 lb/ft without issues. but you are eeeking into a dangerous area there and I would expect problems at some point.

I wanted to run over 450 of each on a reliable basis so the engine built for me by Area 52 Autosport has been over-engineered (as per my spec) in order to do this without worry. I have been able, as a result, to run whatever boost pressure I want (up to 2.5 bar) on bolt on turbos of various sizes and get to 545/600 most recently and I still dont think the engine is stressed too much.

Any engine, badly mapped and not listened to, looked after or maintained well will hold its hands up and say enough. Mine has done 11,000 miles in this spec so far and get used for Time Attack as well as daily duties but I look, listen and (as daft as it sounds) smell for problems.

The myth about 2.5 engines being unreliable is unfounded in my opinion.

 

briliant cheers every one.

 

Here you go, looks like chy rates the block to around 800bhp

Subaru impreza turbo 2.5 closed deck short motor on eBay, also Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles (end time 17-Dec-08 12:04:33 GMT)