Alan Jeffery

Zero failure rate, you?

APIDavid

iTrader: (4)

Silly question mate, our engines NEVER go wrong................

Now where was that lucky rabbits foot??

Alan Jeffery

It's in your drawer, along with the four leafed clover and lucky heather..

joz8968

iTrader: (13)

3 thou vs. 10 thou

That's some serious difference.

Alan Jeffery

You lost me!

Littleted

I have to say that does looks the dogs.

Ok so I quoted the wrong Post but you know what I mean

Alan Jeffery

Thanks Ted!
I'm inclined to suggest that as it's right, it has to look right as well.

Littleted

very neat sir, I must say

joz8968

iTrader: (13)

In that enginetuner is happy to hone out to 0.25mm (10 thou). And API to 3 thou.

How come the two disparate 'schools of thought'?

Is 10 thou okay as to the integrity of the 2.5's cylinder walls, then?

Conversely, is 3 thou, therefore, being 'too cautious'?

Alan Jeffery

API are referring to piston/bore clearance, I'd suggest. If they removed 3 thou from the bore, the stock pistons would be able to run sideways!
A .25mm overbore is naff all, being a wall thickness change of only 5thou.
The trouble with a stock bore is not being able to do anything with it. You can give it a light hone, and that's that. Any imperfections would stay imperfect. If a broken ring land has marked it, you'd have to buy a new block.
Incidentally, we prefer to use our own method of honing to fit, using stress plates.
If you'd like a new block, that's fine, but I'd be quite happy to use one with such a light touch.

joz8968

iTrader: (13)

Ah, sorry for my misunderstanding.

Littleted

ok engine boys sorry to hijack but its been bugging me for months

Went to Norfolk with the Family and went to the WW2 museum there, and looked at lots of cool stuff.

I got to the Tanks and noticed that some of them have MASSIVE engines 12L 20L but what I also noticed was that they were only 2 cylinder or even 1 cylinder.

Why would that be, I thought it would have been a v12 or something else. Was it a design thing for a tank to have less cylinders.

Sorry if you don't know, but my son asked and I made up some bull about bullets damaging engine LOL

any1 ?

joz8968

iTrader: (13)

I'm gonna take a stab at ease of maintenance when in the field?

The last thing you want is to be attending to multiple pistons, etc. - too much time out of commission, too fiddly, etc.???

Plus torque characteristics? Think of a c.1000cc superbike with a V-twin; a la the Duke 916 and its successors.

Littleted

good point

Alan Jeffery

That doesn't sound right! are you sure they were only 1 or 2 cylinder?
EG Sherman tank has a V8, or the M4 version which had an Allison radial
There were 6 cylinder diesels as well.
Some later tanks had V12's based on the Merlin engine.

Littleted

I know what you mean, this is why it puzzled me, they were Russian

jazzyjembreaze

iTrader: (11)

Most Russian tanks were flat air cooled ( flat top ) 4 cylinder
But the design makes it look like a single if u dont look close
The T26 was such a tank
Along with many others

Alan Jeffery

Inspired thread hijack Ted! - Hatches to Tanks...

dsemuk

I love the way this thread occasional bursts back into life with interesting discussion of the various pros vs cons of the 2.5

I am only a few months away from the expiry of my warranty and then I shall be shopping for a rebuild.

Don Clark

http://sovietoutpost.revdisk.org/?p=21

jazzyjembreaze

iTrader: (11)

This is new tech not WW
Can we get back to the EJ257
Case closed ( hopefully ) or I may have to go buy a tank

joz8968

iTrader: (13)

Tanks have hatches.

lol

honeybadger

now the block is weak too? ???

are there any good points in the 2.5 engine?

jazzyjembreaze

iTrader: (11)

It all depends on how far you push the envelope
Remember having a set of pistons & head gasket fix is ideal & a sensible thing to do on the 2.5 , however it's a lot more than that if your after big power or heavy track days etc etc
This thread isn't about putting mods onto your car & hiking the figures up , so for that reason & peace of mind , the block shouldn't come into question . if you have symptoms of HG or ringland or don't feel confident get the package sorted ,,

Alan Jeffery

We've run them at 600 bhp plus no bother. At least one is still running at that level since we built it five years ago. I've seen just one EJ257 with a cracked liner at the top of the bore, but I'm convinced that was due to operator input ie crass abuse.
Given the choice I'd go EJ22 for big power builds, but at 450 ish for road cars I'm not worried at all.

honeybadger

ok, cool thank guys. sorry for asking this again, but is there anything you like about the 2.5?

Littleted

Taking into mind a good job would be to have a fully forged block. Does an EJ22 fit in a new scoob and is that an option or is that way too expensive over and above haveing the 2.5 made stronger

honeybadger

the EJ22 should be expensive to start with, weren't they only produced in the 22B ?

MOTORS S GT

iTrader: (2)

The EJ22 closed deck block was fitted in the Legacy in the US, Autralia etc, not in Europe there open deck, pukka 22B EJ22 blocks don't have the provision for squirt jets.

The cost between a EJ22 block & a closed deck converted EJ257 block would be similar, as all the machining, forged parts are the same cost / labour to build, but the EJ22 would be a far better base, & would also hold value better than any 2.5 unit.

Fitment wise the EJ22 will require a few extra tapped holes for the six speed box / starter motor, otherwise its diamensions are identical.

Alan Jeffery

The lazy torque is nice for road use.
There's nothing wrong with the 2.5 engine if the mistakes Subaru made with it are rectified, and you don't go crazy for output.
Not everybody wants more than 450 bhp, and let's face it, that isn't exactly hanging about! People read too much on forums..

I agree exactly with MSGT on the EJ22, it's just horses for courses!