Subaru 2.5 Spun Bearing

[basketcase]

So, I picked up a little 2 seater in early November that hadnt been really run since early 2010.  It initially (before I got it) had a STI 2.5 with 75# low-z flow matching injectors that had a static flow of 164 and a cc/min @43.5 psi of 492. The ECU was managed by on older Megasquirt II setup.  The previous owner had done his own DIY and tuned it to run E85, but on the dyno they spun the bearings in the STI motor.  He picked up a JDM 2.5 and swapped out the injectors and "supposedly" was running fine.  During the purchase he offered up the STI shortblock that had a new crank, new bearings, arp studs, pistons and rings.  As part of the sale, he had cleaned the fuel system and it was running good.

When I got it, I resealed the valve covers and changed the oils.  The oil had some small aluminum pieces in the oil and maybe some VERY SLIGHT silver glow to the oil, but other than that it looked fine.  On its maiden voyage with me in early November, we put about 25-30 gallons of fuel through it and it seemed like everything was good.  Put it in the trailer and nothing much to do before next trip.

Fast forward to New Years.  I got Covid and my son wanted to take the rail so I let him.  He let it warm up, took it on a quick ride and it was not running well.  Took it back to camp, we chatted.  He cleaned the air filter.  Said it looked like the oil was overfilled, but we both had checked earlier and it was fine.  He ended up sending me a video of it idling. 


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Needless to say he was done.  I had some wishful thinking that possibly it was bad gas.  I was worried that the timing belt had jumped a tooth.  When he got home, we tested the fuel.  It was at 85.  My boy pulled the oil.  It was a full of silver glow.  Pulled the pan and looked like someone had pealed potatoes in there.  Full of shavings and chunks.  And of course, playing with the rods, the bearings were shot.  Ya me.  

So, I am looking for some thoughts.  FIrst of all, I am worried that the tune that is in it needs some love.  I believe it would be foolish to do any fixes on the engine and not address the ECU.  With it being a megasquirt II, I know it is somewhat dated and thinking of having someone do an online tune to see what I had as well as tune it correctly for the e85 once I have the new engine sorted.  

With regards to the engine, initially I had thought of just picking up another JDM 2.5 for $1,300 and sticking it in BUT I do have this STI motor that needs a little work.  At the minimum I know I need a new oil pump.  I was/am thinking of doing a 12MM to up the oiling.  What about using the heads from the spun bearing block?  I was thinking of basically taking the top end from the JDM motor and mating it to the short block.  Anything I have to look out for?  What say ye?

Jonathan

 

[Cookie]

Question, Does it have a turbo (I figure it does if running E85)?  What kind of boost are putting out there?  If it is a non turbo engine, I would pick up an used engine for $1300 and run it.  Easy swap and you are back in the dunes.

Not sure anyone will work on that ECU?

 

[basketcase]

Yes it does have turbo.  I believe it has a 10lb spring in it.  

From what I have gathered, is that most of the JDM motors are the legacy non turbo motors and then, as long as they are setup to be tuned, the turbo is added and tuned.  So close to a direct swap.  Though the factory turbo 2.5 run a slightly different compression, but as long as the tune is good it isnt an issue.  At least that is what I have been reading.

On who can work on that ECU, I couldnt agree more.  I scoured FB and found a group that supports megasquirts using TunerStudioMS.  Even up to the newest version.  There are a couple "remote" tuners out there, but I do get the sandrail might not be up their alley.  Thats the other piece of the puzzle.  The ECU and getting it tuned.

 

[Cookie]

If you are only running 10lbs of boost, go buy the engine for $1300 and do the swap.  I did it once, took 5-6 hours and car was back running. It is pretty close to a direct swap if I remember correctly...................When summer comes you can dig into deeper.

 

[John@Outfront]

Question, Does it have a turbo (I figure it does if running E85)?  What kind of boost are putting out there?  If it is a non turbo engine, I would pick up an used engine for $1300 and run it.  Easy swap and you are back in the dunes.

Not sure anyone will work on that ECU?

yeah we dont tune that ecu.  compression ratios are all over the place--just because you have an sti block that has XX compression ratio doesn't mean that's what you have. that compression ratio would only be correct if you had true sti heads on the motor (which i gather you dont) so your compression ratio is unknown.  this is an area that we are extra critical with (compression ratio) on every motor we build.  the 12mm oil pump is way over kill for what you are doing and is not recommended

no one could ever do a "internet tune" especially with out a dyno, if they did it would be a shot in the dark.  there is a guy "Jack" who camps at the overlook that used to work on those ecus, maybe he could help??

you may have a horrible oil pan, maybe its been cased.  there are a lot of shops that make their oil pan and leave the lower baffle in and it is flat out impossible to clean under that baffle.  your heads are full of crap too and it would be a mistake to reinstall your heads without going through all the oil galleys and pulling out the restrictor in the heads for proper cleaning