big kris

Hi all, I'm pretty new to the world of Scoobs so have a few questions.

I am looking to replace my engine sometime soon with an uprated one as mine has (reasonably) high mileage and unknown history, so its a gamble at the minute!

I am trying to work out what is the best option so please give your opinions.

1. closed deck block with overbore but still close to 2 litre

2. closed deck block to make 2.33 litres

3. 2.5 engine

Looking for a reliable and strong engine for moderate power (400ish) for long term.

What are the pro's/cons of each of the above engine sizes etc. Would be using forged pistons and steel rods for the first 2 options and probably standard subaru internals for option 3.

Cheers

Kris

scoobysmiff

iTrader: (2)

I'm no expert but as i understand things, it's like this:

A built 2ltr is as strong as an ox but with big turbo's can be laggy but also can be made into screamers and still get a good rev range

A built 2.33 with strong forged bits is what most of the "big boy's" use for the big power engine's (i think)
Will offer a good combination between the 2ltr and the 2.5.

And a 2.5 is a good way to get reasonable power quite easily, is better for low down torque and is good on the road, i have heard that they are fragile over 400 though, something to do with pistons and their coatings (if you retain std ones)


I personally would like to take the 2.33 route when i eventually get the money to do it, there are guys on here who are far more qualified to give opinions about this than i as they have done it, i'm just going on what i have read and discussed with other enthusiasts,

i'd speak to Andy forrest or RCMS for an unbiased expert opinion.

Good luck

big kris

Thanks for the reply! Thats pretty much what I was thinking as well, just knew the 2.5 engines were becoming a popular choice, but I like a revvy engine so wasnt sure if it would be what I'm looking for.

Kris

scoobysmiff

iTrader: (2)

well by what i have read, they are not that happy at 7k+ so if you want a revvy engine pick one of the other 2, they will easily be stronger as well if built with forged parts.

What car do you have?

big kris

Aye cool think I could quite fancy a 2.33!

I've got a 95 type RA wrx, and the engine has 151000 KM on the clock, so could be time for a swap soon as I dont want to have the car off the road for weeks on end if I was to rebuild the engine in the car.

Kris

big kris

Still uncertain on what engine offers in driveability and reliability.

Any more thoughts or opinions?? I'm not after mega power.

Kris

big kris

What displacement could I expect from using 2.5 crank and rods with 98mm pistons in a closed deck block bored out to accomodate the new pistons?

Kris

Playsatan

iTrader: (2)

Choices, choices choices.....

All 3 options will get you your 400 bhp but in different ways.

1. closed deck block with overbore but still close to 2 litre - you could always use a 2.5 crank in your 2.0 cdb and get a 2.1. Very revvy, very strong and only slighty down on torque compared to a 2.33.

2. closed deck block to make 2.33 litres - this is what I went for in the end. It seemed like the best balance and having come from a superbike background I like the fact I can rev the nuts off it.

3. 2.5 engine - torque city. You say you'd keep it on standard internals but if you gave it the forged treatment your planning on the other 2 you could push it a lot further. Beacuse of their open deck design there were lots of tales of them not being able to make big power reliably but as things move on that doesn't seem to be the case any more. I know of a couple of BIG power 2.5's that have been going strong for a while now.

In the end it comes down to what you have to spend, what your power goals are and what your driving stlye is. Oh yeah, make sure you have the budget for all the bolt on extras and a decent gearbox/clutch.

scoobysmiff

iTrader: (2)

speak to Olly at RCMS, their Gobstopper is a mental screamer, if you want a real high revvin engine they will be able to advise.

Scoobyslammed

I think the best thing will be to way up how much you wanna spend... otherwise things get out of hand...
My 2.3 build has cost ££££'s... and I'm sure Playsatan's did aswell...
All the little bits add up quickly... but whatever you go for... just do it right...

Are you DIY-ing???

The Chief

Check out Crawford performance in teh U.S.

and import one over here. good exchange rate too

big kris

Yes looking to do the majority of the build myself, things I cant do like overbores and any processes more towards a specialist engineer/machinist I will leave to the professionals!

It will be a project as there is no immediate rush, so would like to first of all figure out which is the configuration that would suit myself and my driving most and then start to accumulate the parts that I require.

I use my car as a daily driver currently and enjoy getting to use it at weekends along the local country roads. I would prefer an engine that is responsive and reliable, hence why I was considering a stronger bottom end to complament whatever option I was to choose.

I know the 2.5 is seen as a very popular option, but I'd be scared that the open deck nature of the block could be a contributing factor to long term longevity.

The 2.33/2.2/2.1 options appeal more to me as they're based on the closed deck block which I know has been proven time and again as very reliable. The bonus here is that each of the above will rev happier than the 2.5, but shouldn't have a huge loss in torque.

The 2.33 configuration seems to be the best for high power, but sounds like the most expensive option out of the lot.

So incase you can't tell, I'm still stumped!

I'll read a few more reports I find through the search option and see what I think.

Any more opinions or information is very welcome!

Kris

big kris

If I was to build a forged 2.5 engine, which of these pistons would I choose?

http://www.importperformanceparts.ne...ns_subaru.html

Engine is an EJ25 and will have an overbore (probably first overbore, will need to inspect closer).

Kris

scoobysmiff

iTrader: (2)

Axis are supposed to be good as well, i've heard