Oldfella

iTrader: (3)

"Bigfella" I wish

I have an ej20 cdb bored and relinered to 2.5. Not the really thick liners. Have run it this year at 1.4 bar, mainly due to still having uk gearbox. New box going in over winter, so will use more boost next year.
Internals are, 79 crank, 99.5 "Lateral" Wiseco pistons, Lateral rods, sti valve train in ported and chambered heads, arp head studs and steel gaskets.

911

Ooops! Sorry! Not sure if you want to be Big or Old!!

I have to say this few days on this thread have been very interesting, especially with such contributions from the Experts in this (mine) field!

I am now in a split position (but have a year to sort it out as I'm resisting actually doing this engine so far )

It has to be a 2.33 (sexy engine and love the idea of all the special bits and potential for the future with a twisted turbo etc)
or
It has to be a strong 2.5 as the advice of AndyF and hillclimb wizzo John Stevenson cannot be ignored. (and can be 'twisted too')

Either way the CDB can do for me, but it wasn't exactly expensive so could sell later...

I know the economics of these options are very important to many who have pm'd me about it all; seems I might be talking for several people on this subject.

I think these sums are pretty accurate:

The cost to do the 2.33 short block
Block £200
Liners fitted/machined/crank and crank mod with some nice pistons £1900
Rods £600
Misc: £500 (RCM pump/gaskets etc)

Total about £3200

The 2.5 short block:

USA unit £1500
Rods £600
Pistons £600
Misc as above £500

Total £3300

The same!
Graham

P20SPD

iTrader: (1)

OH, if only it WAS that cheap when it actually comes to putting it together.

Feature creap, creaps in!

andy97

iTrader: (1)

Graham,

have you spoken to David (Api), he can supply you a built 2.5 engine.

Andy

911

I am sure you are right Steven!
Take ANY budget howsoever carefully planned and double it?
This is why I'm doing the sums now as it is no good getting half way in and not being able to finish it off.

Remember mine will be a mecano kit build not as fine as yours.

Another awkward question:

What can the 2.5 Subaru rods tolerate in bhp/lbft/rpm??
ie, take a USA 2.5 and swop the pistons.

911

Andy: No.
I will be down there soon with the box, but i want to do this one myself in the garage. I like doing these things as my job is so office bound!
Was your 2.5 stock as a short motor?
Graham

Andy.F

John S ran his 2.5 temporarily at 500/500 on std rods, reving reliably initially to 7k, then more revs were needed for a particular section of track (8k) and one rod went rather bendy
Not sure if he has a pic, its sweet

Tim W

iTrader: (1)

Graham, 450 brake 400lbft seem to be the realistic safe limit for the newage rods (same in Sti, WRX, 2.0 or 2.5)

John Stevenson

I can categorically state they can't take 500/480/8000

But the pauter rods can

911

So:
Can you get a bare block 2.5in the UK or USA?

Sorry, but we have drifted for a while off the 2.33 topic, but i think it is relavant to the quest.
Graham

andy97

iTrader: (1)

No, I asked for uprated forged pistons, as the concensus was that the oe pistons could be weak, if going for more than 350bhp, so in for a penny, in for a pound. David's team stripped the 2.5 sti block and fitted cp pistons.

Andy

John Stevenson

It seems to me that there have been a few (very) highly publisized failures/problems with EJ257s, head gaskets not rev'y etc.

As Mark pointed out earlier, the geometry of a 2.5 ain't that different from a 2.3x so why it that people assume the 2.5 won't rev ?

As far as I'm concerned the only drawback is the thickness of the liners in the 257, and if you don't want to run 2+ bar of boost that is not an issue.

My car revs to 8k if necessary, only reason to do this of course is if it is advantageous to hold a gear rather than take a change for just a few metres, but in it's current form it is 100% reliable so far.

An EJ257 with no more than rods and pistons with STi3 Valvetrain is good for 8k IMHO.

Heple

This thread is a really good read.

Not sure if these pistons and rods are still available but if they are i'm sure some of you guys will be interested

Forged Pistons and Rods JE Arias Eagle - NASIOC

(The last time a post was added to the thread was 22/11/2003 though )

JE Forged Pistons & Eagle H Beam Rods $759 = £404

P&P $65 = £35

Total = £439

Craig

911

This thread has managed to break a few myths, and JohnS's comments are particulatly interesting as he does what i do to my car (but quicker..)

It seems you cannot buy a bare 2.5 block, and it is a bit pointless buying a USA new short 2.5 and salvaging the crank and block only.(£1400 for a crank and block)
A 2.5 crank costs about £375
CDB with 2.33 liners/pistons/crank bearings £1550 ish
Rod/brgs £700

Add to this that the 20g might not charge the 2.5 at 6500 + too well, it will stand a better chance with the smaller 2.33. It certainly stuffs the 2 litre well enough!

Seems the balance tips to the 2.33?

Graham.
Misc £500

Scoobyslammed

I had my 2.3 built by Ron @ AXIS for around the 3K mark give or take a few quid... but that included the ARP studs and bolts, Cometic head gaskets, new water pump, plus a few gaskets... etc etc...
I got the Original EJ22t pistons, rods and crank sent back to me... and sold them on...
So really I got my EJ22t short block all built up with uprated rods, pistons... and 2.5 crank... plus a few other bits for less than 3K...

P20SPD

iTrader: (1)

The one thing i did with my 2.5 when i had Uk heads on, was rev it to 7300, but never had a problem, except that the heads just couldnt flow the air well enough.

When i then changed the valvetrain to an STI6 setup, and had the heads extensively ported and the chambers matched to the bore, it transformed the engine.

Its first outing was TOTB4, where we used it in Mark's car, i reved it to 7800, and it got there smoothly, with a big Garrett blowing 1.6bar through it.

It now has JDM sti 7 heads attached to the short block, which resides in Alan Bell's car, and having just spent a good few hours driving it last night, while Pat was mapping, i again can assure it revs to beyond 7600. From a trundle off a round about, limiter in each gear, it hit the limiter in 6th in under 1 mile!

Hand on heart, that car is THE best road car i have driven, and in what must be 8000 miles of hard abuse, it hasnt used a drop of water.

His car has so much grunt about it, i could put my foot down in 5th at 1700rpm, and by 2600rpm i would have full boost of 1.6bar. Doing the same in 3rd at 2500rpm coming off a round about, caused all 4 wheels to light up at 3000 rpm, bit of a controlled drift, and off into 4th!

The turbo that is on the car now, is, quite simply, fecking awesome, it spools so early, you could be convinced to try a bigger version yet!

Steven

Andy.F

Did you mean to type 3000 rpm in 3rd there Steven ? I've yet to see ANY Impreza with enough torque at 2000 rpm to light up all 4 !

stevebt

iTrader: (8)

i know from all the mods alan has done to both his impreza's he is the most impressed with his car in its current state, and he 1st had a 20g on it as well

P20SPD

iTrader: (1)

Correct, i was 1000rpm out on each figure, duly edited. It was a late night, and i am in work today

S.P.Developments

O why O why did I look in here again, the other half is now back from her travels (New Zealand) and is complaining evry time she opens a door/draw she finds another part of the on going build, to this end she has given me a dedline for completion JAN 07, so she can find some where to put the contents of her suit cases...

Does anyone know the where abouts of a 22B spec crankshaft please.

Sorry for the hijack.

John

stevebt

iTrader: (8)

here you go

eBay Australia: 2.2 Stroker crank SUBARU WRX STi EJ20 (item 4624992267, end time 18-Nov-06 16:27:19 AEDST)

S.P.Developments

Thanks for that, already looking at this one, checking to see if any thing in the UK..

John

R19KET

I'm sorry, but the link is to what they are calling a "stroker crank", which I assume is stock 2.5lt 79mm crank forged, not billet).

The 22B uses a standard phase one crank, which is 75mm, and available from most Subaru parts specialists.


Mark.

911

Oh Steven WHY did you have to post #166!?
How would you temper the 'feeling' with that engine on a 20g?

So; why did you go to 2.33 after that 2.5? AND did you port the heads for the 2.33?

I feel there are some futher bits of detective work yet to come..

Great thread, you are all making it so interesting for us Newbies to Big Engines.

Graham

The Fixer

I see the thread is coming on nicely

Graham, budget in for the head porting and chamber matching work and a nice set of cams I did try to pm you re liners but your inbox was full.

In terms of RPM limits, another consideration should be piston weight. The 2.5L using 99.5 / 100mm pistons against the 2.33L using 97.5 / 98mm pistons. Not sure of the weight difference between the two variants as I havent had both sets on the scales at the same time. I know 2mm doesnt sound a lot in terms of the diameter but they will be considerably heavier on the 2.5L.

My Ducati race bike engines (100mm pistons) revved to 10,500rpm but they use very lightweight Ti rods to keep the weight down.

As Mark said earlier, revving past 7500 RPM will need a substantial size turbo that doesnt run out steam past this RPM limit.

If you can make the power you need lower in the RPM range then why rev it further ?

Conrad

John Stevenson

Thats why

911

Odd as it may sound I'm not after maxing the engine, just getting a better hillclimb engine from a short engine change using my current 'peripherals'.

And i'm not doing this for a year yet..

If only you could buy a bare 2.5 block..but nobody has said why the 2.33 is favoured over the 2.5 other than Conrad and the very good reason of piston weight.
But that may not be relavant as John has stretched the 2.5 to 8K anyway.

John: I am sure the 2.5 with 20g would make a great hillclimb motor with a twisted conversion to follow, ie following in your foot steps, but buying a USA shortblock and chucking the rods/pistons seems a waste. It makes the block £1000 effectivly.

I also see the boring subject of gearboxes looming.

I know my Sti v3 will tolerate the 380 x 360 i have, but will the TY 754 Type R box go to 400 x 400?

Graham.
Off to the garage now to actually do something rather than read this thread!

P20SPD

iTrader: (1)

Quite simply, i think the 20g *might* just feel quicker upto 3000rpm, but after that, it will have its **** kicked by the MD321T

Why did i change to 2.3 from the 2.5? Good question, but simply, at the time i didnt think the 257 would live up to the abuse i was wanting to throw at it, ie 2bar plus, and having driven Mark's 2.33 with wilder cams, i wanted the 8500rpm limit to go with the 5 speed box. The car was moving away from being an everyday car (but bizarrly i stopped myself stripping it and caging it, so it is still driveable on the commute)

The 2.5 never lived upto my expectations until the cams went in with the modified heads, but by then, my mind was set on a 2.33.

My 2.5 modified heads and cams, now reside in Oldfellas engine bay. The heads i have for the 2.33 have had even more porting work done, plus wild cams, single piece valves, and double valve springs, and to repeat that spec would cost well in excess of £2k.

I was only saying to Alan yesterday, that i probably have the best part of £12k in the engine department, let alone the drive train, which so far hasnt stood up to me driving!

As i also said to Alan, i sometimes love the cars i tinker with, but other times i could easily knock ten bells of crap out of them with a sledgehammer.

R19KET

Conrad,

But in this particular case, the 2.35lt pistons are actually heavier than the 2.5's, and are being revved to 8000rpm + on a regular basis.

I'd be more concerned about the type of bucket/shim, than the size of piston.


Mark.

Oldfella

iTrader: (3)

Graham, after reading all your posts on this thread, I cannot help but think that you are leaning towards the 2.5 route but feel the perceived extra cost is prohibitive ie. having to buy a new 2.5 short block and then throwing half of it away.
Have you considered doing what I had to do, converting the 2.0 cdb to 2.5, you already have the block and the machining costs + internals would be the same as the 2.33 build.
I am certain there will be views from people with far greater experience than myself, and I would welcome their comments.
For low down grunt, didn't some American once say "there's no replacement for displacement"
I am in no way advocating this way forward, what I had done was at the time more out of necessity.

Mike