How much should i expect to pay for a 2.5 short motor
 

I think ive decided im going to go for a 2.5 build for my new engine project. My aim is for 500 bhp and all the extra torque the 2.5 offers. I know i would be safer with a 2.1 forged stroker conversion or a 2.35 but although a slight risk at that power the 2.5 seems very appealing.

A few Question I have ????

What are the price differences between building a forged and strengthened 2.5 short block vs a 2.1 cdb stroker biuld ??

How much should i be looking to pay for a dead 2.5 block thats needing a rebuild and any preferred variant ?? and what should i look for and avoid when buying one ??

Cheers

Dubzy :thumb:

The man you need to speak to is Alyn @ AS Performance.:thumb:

My vote would be to go with Alan jeffery enginetuner. Not saying Alyn isn't a great bloke mind :)

I mentioned Alyn as he's after information about the 2.5 and he's the man doing the cdb inserts for them so probably able to point him in the right direction with regards his queries running big power on the 2.5.

You can also de-stroker the 2.5 to 2.35.

P.S, my choice of engine builder would be Paul Finch @ Motors GT. ;)

Thanks for the replies, im guessing there wont be too much price difference in the 2 builds mentioned ?? i will give Alyn a call and find out the pros and cons and the real costs involved.

Are there many members running a 500+ 2.5 motor as i would love a passenger ride to really help me make my mind up, I wouldnt mind travelling a bit for the experience and first hand knowledge of someone thats done a similar build ??

You could try sending Shaun a pm, but I doubt he'll have anything good to say about running a 2.5 at those levels.:lol1:

To be honest mate if it was the best way to skin the 500bhp cat there would be loads of them out there, so I'm guessing there's a very good reason it's the road less travelled.

2.1 or the more expensive 2.35 using a 2.2 block will do it cheaper than 2.5 inserts or de stroked and they are well proven to run that power all day provided the right man builds it.

Personally I would aim a little lower if you absolutely need to have the 2.5 say in the region of 460bhp, but then again I would just do it with 2.1 and twin scroll.

Wasting your time & money running a 2.5 at 500, unless you want to rebuild frequently, either aim lower, as stated above, or go 2.35 or 2.1 closed deck blocks.

Thanks for all the input guys, i am aware that the 2.5 would be a less reliable option at this level but whilst having my car mapped today i was lucky enough to go for a passenger ride in Maz's (member on here) lovely spec d with a 2.5 running 2 bar on md321v and i was extremely impressed to say the least. The car pulled effortlessly in every gear with loads of low down and mid range torque with the top end to boot which is really what im after.

All i need now is a passenger ride in a 2.1 and a 2.35 to see if my mind can be swayed..

Should have gone for a ride in his old RB5, 2.5 with twin avcs and a gt35iirc, it was savage :thumb:

Nice guy Maz :)

:idea: 2.23?

these seem popular for some reason and also supplied to various other tuners also.......;)

http://i58.photobucket.com/albums/g2...psf3135cde.jpg

Lol , sorry if I had you dabbing the brakes in the passenger seat ! 😀

:norty:

Yep , only an scd block , pinned , 14 mm studs ! Built by mark at td ! Ran 475 then 575 bhp :norty:

No issues with it ! Was I lucky or is it that bad news travels fast ? Running another car now which is 2.5 and runs a treat ! Had it running at 528 bhp ! No issues either !

What does your 2.5 rev to tho. Has it had head work so it can rev as much as a 2.0? I really prefer the 2.0 but want to go for something big next year and I dont know if it will be 2.1 2.35 or 2.5. 2.3 seems abit expensive

Haha , does it really matter what it revs too ? It's a quick road car as the o.p can tell you !
Standard heads and cams ! :thumb:

Lol im asking cz im looking into options for next year n want something that will be quick on road and the strip :)

:luvlove::luvlove::luvlove:

If you want a really revvy car then get a mini with a busa lump ! :D

Only joking ! 2.1 then for both road and strip I guess or 2.3 or how about destroking a 2.5 to 2.3 ? Ring mark at td racing as he has just done this to his own 2.5 and just run it in :thumb:

Haha are my hand prints still on the dash from the high speed braking demostrantion too lol, very impressive car mate and superb power delivery, think its got to be a 2.5 or 2.35 now for sure :thumb:

How does de-stroking the 2.5 affect its power delivery and power handling capabilities ???

Marks just pricing up the various builds for me before i make the final decision and start the ball rolling..

To answer the title a fully forged 2.5 short engine from me is £2500, to answer a few questions regarding capacity and stroke differences, put simply a larger capacity engine will always spool quicker and produce more torque. If it its increased by stroke it will be a less rev happy enigine but produce more torque, a shorter stroke will make it rev better but less torque. Think of it like peddling a bike, longer crank will get you up the hill easier but it would be hard to peddle fast.
I do have a fresh 2.6 engine if you are interested, steel crank, rods, Manley pistons, pinned ej257, arp studs, avcs heads £5K ready to drop in and go :-)

:luvlove::luvlove::luvlove::luvlove::luvlove::luvl ove::luvlove:

I have owned forged 2.5s and 2.1s all running 450 - 500ish.
I abuse mine on track so I currently have a 2.1 - as it is a proven strong platform for high power.
Until Alyn brought out his CDB inserts I would say forget the 2.5 at that power. However now that is an option from him I would seriously consider it.

2.1 internals are the same price as 2.35 - the price difference is the block. A bare 2.2 block is far bigger money than a bare 2.0 CDB
Also ask who will be doing the machine work as that is as important as the build.
On a subaru block I personaly would let SMG, AS Performance and Engine Tuner near it as far as machine work went. That couple with a good builder should make for a good job.

A loose gut feel of the two engine is -
2.5 lazier power delivery, more torque, kind of more of a relentless German style power delivery. 2.1 A bit more punch, more of a subaru kick in the back delivery. Less torque more hp in flavor. Lots depends on turbos, mapping blah blah.

It also depends where you use the engine
Out in Germany kicking AMG arse down fast sweeping back roads the 2.5s were the better engine
On the shorter tracks, I drive now, I am mainly in 3rd and 4th so the revier 2.1s are the better solution

So also have a think about where and how you will use it
Cheers
Steve

Cheers buddy, some useful info there. Im guessing the 2.5 forged build is on a stock/ un pinned block ?? how much would it be with the pinning included ??

The 2.6 ej257 sounds very nice but something i know very little about, how does it compare for safe power handling capabilities ??

Exactly the info ive been looking for and some serious food for thought. I live surrounded by a network of open dual carriagways which are heavily trafficked by big german motors that think they rule the highways lol, i will also be doing the odd track day and quarter mile run.

What power level is safe ? I have run 575 on a 2.5 scd with a pinned block , the same block then did time attack at over mid 600 bhp ! Maybe it was luck ? Maybe bad news travels fast ? Most builders seem to say keep the 2.5 to 450 ish and you'll be ok :p !

When I need a build next it will be going to alyn at as performance for closed decking :thumb:

Maz ;)

pick a tuner, speak to them about you want, get them to spec and build it, install it etc. you can take the best parts in the world but if they are mismatched it will be a crap car.

I recon the pinning was worth its weight in gold :) ...and you had a dose of luck :D

What Maz said really, some engines are just capable of doing more, Im running mid to late 500's on an open deck 2.0.... *touch wood*