So, my bottom end decided to go today without any warning. Driving with the missus and little one with dog in boot and then heard the dreaded sound of rod knock - clack clack clack..

Owned the car for a month and driven 600 soft miles. I haven't hammered it and it's been pampered mechanically in the short space of time I've had it.

Either way, it now needs rebuilding. I've never had to have any of my previous scoobs rebuilt and the car is now sat in Enginetuners car park awaiting dismantling.

I know how easy this is to get carried away and Alan's already indicated a figure BUT I need to be realistic and not get carried away with adding things on that I don't need. I'm not after any real hike on power as was happy with stock. Basic research suggests the following essentials;

RCM head gasket kit
Nitrited crank
ACL bearings
Standard head bolts
Forged pistons
Standard con rods

Then whilst apart service items:
Generic Cambelt kit
Subaru water pump
Subaru Rocker gaskets
Clutch

Appreciate any guidance to help inform me prior to the expensive convo with Alan.

This is her, parked shamefully awaiting recovery earlier today:

 

Sorry to hear this, I'd definitely add forged rods and arp head studs as a minimum to just future proof it, and at least it's at the right place for the rebuild👍

 

How much extra do you think that would add to the bill??

 

I am sorry to hear this.
I'd only add ARP head studs (from what I've read).
Check the condition of the modine coolant pipe and replace if rusty.

 

Would be worth spending a little more on the build, will help you a lot when it comes to resale.

Your existing crank should be ok.

 

Sorry to hear this. I drove past Exeter twice this morning, and was thinking about your car. The thought did cross my mind that it was off loaded on you, but I guess it's irrelevant now

 

Personally I would go with what Alan offers in the way of advice and recommendations. Great guy and brilliant outfit.

 

Thoughts on these?




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Rods are a must while its apart, also i'd seriously consider closed decking while its fully stripped as well.

 

Why forged rods and closed deck for a "stage 1" tune? It's unnecessary spend, the OP has said "I'm not after any real hike on power as was happy with stock".
Regarding the baffled sump, do our cars suffer from oil starvation? If you plan to track it often it's not a bad idea I suppose.
I don't think you'll feel any difference by fitting lighter pulleys in a turbo charged car but that's just my opinion.
It's very easy to go down the slippery slope and start upgrading parts that are not necessary.
I'd stick with the advice of the builder based on your requirements and the car's usage.

 

you have to consider resale aswell ,, iv been a member of the hatchback groups for a long time now and most people won't touch a 2.5 unless its been properly forged and not just pistons ,, closed decking , rods and head studs are considered a must for any build really ,, I personally won't touch one unless these things have been done

 

Really helpful advice this and what I need to reign it in. I'm not wanting to update turbo, injectors and go FMIC etc.

Closed deck is appealing as I like the idea of a strong engine.. will be approx £450 to the bill. Is the closed deck only worth it for big power?

Tia 👍

 

ha thanks for the thought. Yes it was a sickly feeling when I heard the clacking. Was no warning at all just came on instantly. I have a dashcam fitted which would have caught me sounding pretty somber 😭

 

the 2.5 has a nasty habbit of ovaling the bores or even splittng them once you hit 450bhp and above, so for £450 for future proofing i would say def if your intending to keep the car a while.

 

If you are going to spend £4k+ on a rebuilt though another £450 wouldn't be a huge difference in the grand scheme of things I agree but if the OP plans to stick to the Prodrive map power levels (or less than 360bhp which is the turbo's limitation anyway) this is simply unnecessary IMHO.
Personally, I'd build my car for my use/requirements not if/when I sell to satisfy a potential buyer's interest in building a 600 bhp monster. Unless the budget isn't an issue, of course.

 

im yet to find anyone who did a half forged build and not regret it later. Not saying thats always the case and there is alwasy budget constraints, but decnt rods and closde deck now circa £700-£800, doing it later £4k. Half forged is a big off putting point for potential buyers and will reduce the resale price alot.

 

iv tried saying this but was ignored lol ,, I won't touch a 2.5 without it being built properly and I know most others who know the 2.5 will say the same ,, but everyone assumes its power chasing lol ,, seems odd you would spend all that money and not make sure its future proofed

 

Point taken but I'd listen to what a reputable engine builder would advise me.

 

or possibly to people who have had them built and are still going strong after being properly pushed and tested lol ,my old one is still going strong after many many years now and is still running over 500bhp,, a lot of builders won't rate them over 450bhp ,, thats the builders I wouldn't be using as what's the point in spending all that money and have a "forged engine" thats only rated the same as the standard 2ltr will take ,,, id want it rated to at least 500bhp just for the extra head room so I could make the most of that extra torque lol

 

Do you have a problem with Enginetuner then? Because that's the context of this thread. You are fairly unique on here in being able to develop what you want, at trade prices , as you have said before. The op has a young family, and has just spent a considerable amount on buying the car; he's also probably worried about employment in the next 2 years ( my assumption) No doubt he's already under pressure to add lots of RCM ancillaries, but he has clearly stated he only wants stock power levels.
Just because those " in the know " would only buy a full fat closed deck 2.5 ( I'm not disagreeing here) it doesn't mean that an Enginetuner built lower spec build would fail to sell. No one gets their investment back on a built hatch from a reputable builder anyway. Unless you're going to do it for him at cost of course lol

 

They have done some odd things, like swirl plts in the engine bay. But I think there is a concern its going g to be another API now its been sold.

 

In my opinion you don't "need" to run forged rods or a closed deck if you are looking for moderate power (400bhp or less) but it would be good practise for a number of reasons. Even at moderate (and standard!) power I have seen 2.5's crack their cylinder walls due to cylinder flex, and a closed deck inset would help to minimise this. Rods can go if the torque is high, which is often the case with these engines as they don't like to rev, so the power is made in a very small band, however this can be pegged back when mapped. Personally I've always felt that building a 2.5 without a closed deck and uprated rods is only really doing the job half properly, and it could still fail. Save for a bit longer, get the inserts and also consider the 14mm head stud conversion (11m studs can still suffer with heads lifting). You may be happy with less than 400bhp initially, but if you find you get bored with that, you'd kick yourself for not spending the extra money in the first place. You can spend circa £4k and have a useable engine, or circa £5k and have something that will have all the safety precautions you would likely need in a road car. As has also been previously mentioned, the resale value of the inserts, rods etc would likely be far more attractive to a new buyer. Just my 2p worth.

 

Thanks for the input guys, from both sides. I know Alan will cover off most my questions when it comes to 'speccing' the engine and working out the best setup for me, I purely started this thread to see peoples perspectives on spec themselves from an owners perspective and what they think is necessary.

Well aware of the desire to always want more power but a relatively stock map 350 - 360bhp with 4wd and decent handling setup would make a more than capable hatchback.

General consensus is then;

Uprated pistons
Uprated conrods
Uprated head gasket
Uprated crank
Uprated bearings
Uprated head bolts
Closed deck

The head bolt conversion (14mm), would I really need this for a relatively stock map. I thought this was only really reserved for the 500+ builds?

 

Only correction i would make is the studs. You can get 11mm that are plenty strong enough to not lift the heads even at 500bhp. Like pistons it depends on material spec

 

I agree Tidgy, and would most likely be more than sufficient for most, but personally for what is relatively low machining costs (similar to close deck inserts) I’d go the whole hog to make sure it’s belt and braces. Not saying that OP would need to go that far, but I would personally as I think peace of mind and confidence in these engines is priceless.

 

nothing against engine tuner ,,,most dont even realise iv still got one of Alans original 2.1 stokers from when they first done a metal offer on them many many years ago now so I know them from personal experience lol,, my concern would be wanting it spec'ed higher than most builders are willing to build to as iv spoken to quite a few about building engines over the years and a lot dont want to cover engines over 450 power levels on a 2.5 ,,, as a long term member of the hatch groups on here and on the Facebook now lol ,,, I can honestly tell you that 99% out there dont want a semi forged 2.5 and if its not done to a certain level the price of the car drops a hell of a lot , seen forged hatch's with just a semi forged build go for as little as 8k ,, but with a properly built one go for 14k and both were very similar in miles and spec , just the engine was built different , one sold strait away and the 8k one was posted around everywhere with poeple saying about the engine not being up to scratch due to rods and head studs not being done ,,, just trying to save the OP this in the future as no one wants a car thats hard to sell ,,, the lad who had mine waited 7 months due to knowing it was built right lol

 

The head stud is a personal choice, the 11mm ARP studs are good and as you say should suffice up to 500bhp, but for the sake of a few hundred extra pounds I'd always take the option to upgrade them while the engine is out. It's very easy for an engine build to snowball and it can become very expensive, but for me it's one of the best pound for pound modifications you can make to these engines in terms of longevity and safety factor. I can totally understand if it's one step too far for you, just giving my own view on what could be done seeing as you have a few options open to you.

 

If it was me choosing, I totally agree. There are builders, and there are highly regarded builders. But like the OP, many 1st time buyers do buy unforged or poorly forged, or we wouldn't see so many of these threads. And they take the double hit of purchase cost and forge cost.
Too many commit to a complex bit of machinery without having the money behind them to maintain or repair them well.

 

I'm not much help here but at 60,000miles I would say there was something not right with the car beyond the usual 2.5 litre horror stories. It's well known that these lumps have the least running fault tolerance out if all of Subaru's engines. So if I were in the OP's shoes I would be paranoid of it happening again if that root fault that was not found...for example an injector that was out of kilter (low use car, phase separation of fuel in the tank, could be plausible). As such I'd be looking at replacing pretty much everything related to fueling and ignition, as well as strengthening the existing lump with plenty of error margin in the ECU map for the odd duff tank of fuel (i.e a garage inadvertently dispensing 95RON from a SUL pump ).

And with the costs of going Forged, closed deck etc...Does anyone know the feasibility both in cost and availability of obtaining a JDM spec 2.0 lump with a twin scroll as a complete turn-key package (including turbo, injectors etc)? I guess for that year it'd be a EJ20X or .EJ20Y? I'm guessing these engines are unicorn s**t in the UK (not messed with scoobs for well over five years now so I'm totally out of touch with what's about these days; Unless a JDM Legacy lures me back).

 

Unfortunately the twin scroll engines still use the Hypereutectic pistons so are still prone to failure. the 2.5 is a fantastic engine when built properly and I firmly believe that makes the best road going engine of the lot due to the useable torque. The 2 litre engines do like to rev, and the twin scrolls are an improvement with the way they deliver boost, but still not on par with a properly built 2.5 in my opinion.