So the Foz is in for it's head gasket this week, it's got just over 120k on it so I'm not entirely annoyed. I'm just slightly annoyed that I was going to start an engine build in the new year and this is just money away from that, but hey ho. I'm getting ARP headstuds and Cossie gaskets, but is there anything else worth doing while the engine is out, I was thinking of doing the bottom end but I don't know how many other gaskets and seals breaking the block would need. My thought process with doing the bottom end is that I'll have a solid engine to sell once the new one is built. Though the bottom ends in Subarus are relatively strong so I'm just having a stab at a guess when I think most bottom end failures are caused by the oil pump seal? Thoughts anyone?

 

with 120k needs whole engine doing mate, crank bearings and the lot. My dads car had some fried valves, engine was on 114k, stripped it down inc bottom end and found major bearing damage that had it not been done would have failed within a few thousand miles.

Needs a full refresh if you want it too last

 

Sound advice

 

Cheers, I was half thinking of going that route anyway. I also have a set of 2010 STI rods and pistons with 10 miles on them (I got them for pennies so if they're no use I won't be too pissed). Will these fit an an EJ255 WRX engine, well I know they'll fit, but are they compatible in terms of dish volume and CR and assuming the cylinder's round enough?

 

Yes but don't fit the pistons, get a set of forged pistons for it, a small price to pay for peace of mind.

 

It's not! Quite the weakness I would say.
Get the valve stem seals done while the heads are off.
A fresh set of big end bearings is always a good idea with the inherent weakness of the middle ends. Atb

 

I'm starting a full engine build in the new year anyway. I'm only at ~275hp just now.

 

Pistons won't be a problem, haven't been a problem for 120k miles. I would even (have done) use the rings again as long as they are serviceable, just hone the bores

 

The main issues in them has been the big end bearings wearing out, this is due to them being relatively narrow for the power they run. Since the 2.5 has been on the market piston failure has taken over as the biggest problem, they are made froma sub standard material and they crack in between the ring lands.

 

Oh and hi andaru!

 

I thought you were in Scotland? Not Lower-Englandshire!

 

You can't say that without it being stripped and inspected. I recently rebuilt 7 x 2.5's one after another, only 1 of them came with piston issues, after stripping them, all bar one had cracked pistons. One had only done 45K and was running sweet, all the pistons came out with cracks and you could pull the broken part out once it was out of the bores!

 

I am, like to keep people guessing. Born in Essex however

 

Is this a 2.5? Inspection required if so.

 

I'm currently running reused head gaskets with a smear of hylomar, no coolant use or any issues at 320bhp 1.5 bar boost for over 6000 miles now..... Old head bolts re used and second hand pistons and rings in a second hand GX block of unknown history and origin.
Building a decent spare engine just now, but I won't be puttin it in until this one shows a problem, which it's not doing yet!
My point is that it's all about having the eye for what's serviceable and what you can get away with.

 

Certainly redo the bottom end...have a word with David O'Brien at API if you don't believe us.

New oil modine, new water pump, new cambelt, idlers and tensioner, uprated water pump, forged pistons, and rods if you can stretch to 'em.

 

Calm doon, this is just to freshen up an engine so that he can drive the car on the road until the forged engine is built!
I doubt every single rotating assembly needs replaced

 

Doubt what you like, but he says the car has done over 100k?

So it makes sense to replace stuff while the engine is out, yes?

 

New oil modine (£300)new water pump(£50), new cambelt(probably already been done) idlers and tensioner(£100?)uprated water pump (just the one pump or two) forged pistons(really? Why build two forged engines £500), and rods if you can stretch to 'em.
£950 plus labour and the head gaskets!
I'm trying to be constructive here, that's a lot of money on a repair that doesn't have to last very long. And will it add £1000 to the value of the engine when it gets pulled out?

 

You don't need a modine unless it's suffered bearing damage, water pump is worth doing for the cost, rods should be fine. I agree this build doesn't need money wasting on it but a set of pistons, good bearings and decent headgaskets with make it a solid engine and will have a decent re-sale value or could happily run at 400bhp.

 

Agreed, perhaps better the devil you know and spend all your cash on this engine now. Just depends if andaru can afford to be without the car/financially just now.

 

There is your problem, just buy a banger for £400 and run that for a couple of months, old fiesta or polo should do the job, then you won't be wasting money on 2 engine builds and a hire car.

 

If your not fussy then you can find some bargain cheap cars, Toyota carina in Dundee tested for 1 year £475 just now. For example.
It will still be worth £400 in three months time.