Need help from EJ25 peeps. What's up with these pistons on my '05 Legacy?

anarchyx34 · 08-05-2019, 10:39 PM

Long story short, I picked up a dirt cheap (but clean) N/A '05 Legacy that had a "broken timing belt" (it actually was a sheared tensioner bolt). I pulled the heads and eventually realized the car has the wrong heads. It's got dual port heads but the single port exhaust. So either this thing had a head swap at some point, or the entire motor. I'm not sure which.

The pistons are what gets me though. I was a subaru tech in the mid '00's and I don't remember the pistons looking like this.
https://i.imgur.com/CVUdYSh.jpg

What's with the dual valve reliefs? At first I thought the valves made those marks but some of them didn't even hit (there was only 4 bent valves in total). Besides they're all carboned over. If the valves hit them they'd look fresh.

So... what am I looking at here?

If this is how they normally look then I'll just slap the correct heads on and call it a day because the rest of the motor is spotless. AFAIK pretty much all N/A EJ25 blocks are interchangeable anyway right?

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Blktrax · 08-06-2019, 12:07 AM

Well , that’s a new one to me... not Cali Spec pistons , and single exhaust port on each head would be Cali spec as well.

I think that has to be some type of Jasper , ATK, Fed/Mogul reman shenanigans.

anarchyx34 · 08-06-2019, 08:16 AM

So those are non-cali spec pistons? What's difference with the Cali spec ones?

The heads are dual port. They've been running it like this:

So it seems the whole motor was replaced with a non-cali spec one. So the big question is there any reason I can't just use this short-block with cali-spec heads?

anarchyx34 · 08-06-2019, 11:25 AM

Just something I've found. I was looking for a picture of the difference between CA and non CA pistons and found this:

https://www.google.com/catalog/20...iston_set.html

So if this is to be believed, Non-CA means dished pistons, CA means non dished pistons. Which would mean that I do have CA pistons, but that doesn't explain the extra set of valve reliefs that just straight up look weird to me.

anarchyx34 · 08-06-2019, 01:49 PM

Ok another update. Someone on reddit said they look like IKON pistons, so I looked it up, and holy **** he's right.

https://i.imgur.com/iYhcqEN.jpg

That would be really odd for high performance forged pistons to make their way onto a bone-stock automatic N/A legacy. I'm going to guess that these are just regular aftermarket cast replacements. But the thing I learned is that the 8 valve reliefs are so the pistons can be used on either side. Never seen some **** like this before but I think it's ok to use.

anarchyx34 · 08-06-2019, 04:18 PM

Gets even weirder. I just looked at the engine again. It's an EJ20.

tipsymechanic · 08-16-2019, 08:05 PM

Quote:

Originally Posted by anarchyx34

Gets even weirder. I just looked at the engine again. It's an EJ20.

I'd say that's your problem right there!

I can't even fathom how bad it must have run with that exhaust setup!

08-05-2019, 10:39 PM	#1
anarchyx34 Scooby Newbie Member#: 504950 Join Date: Aug 2019	Need help from EJ25 peeps. What's up with these pistons on my '05 Legacy? Long story short, I picked up a dirt cheap (but clean) N/A '05 Legacy that had a "broken timing belt" (it actually was a sheared tensioner bolt). I pulled the heads and eventually realized the car has the wrong heads. It's got dual port heads but the single port exhaust. So either this thing had a head swap at some point, or the entire motor. I'm not sure which. The pistons are what gets me though. I was a subaru tech in the mid '00's and I don't remember the pistons looking like this. https://i.imgur.com/CVUdYSh.jpg What's with the dual valve reliefs? At first I thought the valves made those marks but some of them didn't even hit (there was only 4 bent valves in total). Besides they're all carboned over. If the valves hit them they'd look fresh. So... what am I looking at here? If this is how they normally look then I'll just slap the correct heads on and call it a day because the rest of the motor is spotless. AFAIK pretty much all N/A EJ25 blocks are interchangeable anyway right? * Registered users of the site do not see these ads.

08-06-2019, 08:16 AM	#3
anarchyx34 Scooby Newbie Member#: 504950 Join Date: Aug 2019	So those are non-cali spec pistons? What's difference with the Cali spec ones? The heads are dual port. They've been running it like this: So it seems the whole motor was replaced with a non-cali spec one. So the big question is there any reason I can't just use this short-block with cali-spec heads? Last edited by anarchyx34; 08-06-2019 at 11:06 AM.

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08-06-2019, 12:07 AM	#2
Blktrax Scooby Specialist Member#: 220971 Join Date: Aug 2009 Chapter/Region: South East Location: NC Vehicle: 2004 Impreza	Well , that’s a new one to me... not Cali Spec pistons , and single exhaust port on each head would be Cali spec as well. I think that has to be some type of Jasper , ATK, Fed/Mogul reman shenanigans.

08-06-2019, 11:25 AM	#4
anarchyx34 Scooby Newbie Member#: 504950 Join Date: Aug 2019	Just something I've found. I was looking for a picture of the difference between CA and non CA pistons and found this: https://www.google.com/catalog/20...iston_set.html So if this is to be believed, Non-CA means dished pistons, CA means non dished pistons. Which would mean that I do have CA pistons, but that doesn't explain the extra set of valve reliefs that just straight up look weird to me.

08-06-2019, 01:49 PM	#5
anarchyx34 Scooby Newbie Member#: 504950 Join Date: Aug 2019	Ok another update. Someone on reddit said they look like IKON pistons, so I looked it up, and holy ** he's right. https://i.imgur.com/iYhcqEN.jpg That would be really odd for high performance forged pistons to make their way onto a bone-stock automatic N/A legacy. I'm going to guess that these are just regular aftermarket cast replacements. But the thing I learned is that the 8 valve reliefs are so the pistons can be used on either side. Never seen some ** like this before but I think it's ok to use.

08-06-2019, 04:18 PM	#6
anarchyx34 Scooby Newbie Member#: 504950 Join Date: Aug 2019	Gets even weirder. I just looked at the engine again. It's an EJ20.