Thinking about building a SOHC 2.5L to put in my 98 OB ( I know #3 rod bearing failure is probably gonna happen in the next 40k miles, so I wanna have a drop in replacement ready)

 

What year's had what problems? I know the 2000-2004 were prone to external HG leaks.

 

Is is worth using the active valve timing on the 05/06 blocks? I have wiring harnesses out of a 05 Forester that had the valve timing on it. I dont know if I'm a fan of the electronic throttle, I see its pros and cons. Def doesnt have the finesse that cable throttle does

 

I remember reading on a thread that certain years of the EJ253 were more prone to rod bearing failure similar to the EJ25D.

 

Thoughts? Ideas?

I'm fairly certain you'll have success either way with good oil supply and never overheating the block.

 

Use the EJ25 turbo headgaskets if you're sticking with OEM gaskets.

 

Haven't dug into the variable valve stuff yet.

yeah, because of screens in the banjo bolts, avvl (and turbo) oil supply really needs to be CLEAN and , likely, synthetic oil. That should help with bottom end lubrication too.

 

and my 06 WRX is DBW, there's no more throttle 'lag' than any other fuel injected car I've driven, and less than some.

 

that's about the limit of my help on a project like this, sounds fun!

Edited November 1, 201213 yr by 1 Lucky Texan

the rod bearings on the single cams are bigger than the ones on the 25D's. My 25D lost a rod bearing and I did what anyone would do. I bought a phase 2 shortblock and rebuilt it.

I never thought about the turbo headgaskets, are they o-ringed around the coolant ports? I never bothered looking because of the coolant passage differences and the thicker metal around the cyl liners on the turbo blocks.

 

God I need to get a sidejob at the dealerships parts dept so I can get these parts for cheaper lol

I never thought about the turbo headgaskets, are they o-ringed around the coolant ports? I never bothered looking because of the coolant passage differences and the thicker metal around the cyl liners on the turbo blocks.

i've never looked but i don't think they are oringed. more robust design and the Turbo engines never blow headgaskets (well, normally. people blow those motors all the time!).

 

God I need to get a sidejob at the dealerships parts dept so I can get these parts for cheaper lol

do

you get the discounted prices or order online? or you mean those prices are still high? my local dealer matches the online prices.

I fix alot of both the 251 and 253 and find the only bottom end problem was the leaking headgaskets customer runs oil low and berrings are done. I think its just a runing out of oil problem not a engine problem. And i see some realy high km 251s and 253s but all have never been run low on oil or overheated.