legacycentral bbs

Hi !
Does this piston looks like a Forged STI V2 piston, or more like a standard JDM ej20G piston ?





Thanks for your help. This engine was sold and installed as beeing a STI V2 engine... but with pistons that looks casted, and full open deck block ... that looks more like a ej20G block, and that my friend got fooled.

but we need confirmations to proove it ! :\

I don't know the answer to what you're asking but I thought the US didn't get the EJ20G and that it was closed deck. Isn't the EJ20G what the Liberty RS and Euro Legacy turbos have? Didn't at least the first 2 STI versions also have the EJ20G?

Yeah, the EJ20G is the Liberty/Legacy RS engine and it's closed deck as far as I know. The US market never got any 2.0-liter engines until the WRX.

Later EJ20s, even the turbo ones, are open deck.

According to You & Your Impreza Turbo, all EJ20's after 1996 were open deck (although the stripped RA may have remained a closed deck for another year or so, I can't remember). I believe the 'G' designation was what denoted a closed deck block. Later revisions had special thermal coatings that supposedly made up for the lack of rigidity of an open deck, which is why Subaru justified the change, but I'm sure just economics were a major motivator. Aren't they always.

Steve

Sorry, my bad, i wrote that quick this morning and wrote usdm instead of JDM ! hehe

In fact, we don't know what is the engine block. It was sold as beeing a STI V2 block.

It has a TD05-16G turbo, and DOHC heads. in 1996 , both Standard WRX JDM and STI V2 had that turbo. But STI V2 block is supposed to be close-deck.

The block we have is open deck. We are trying to identify weither it's an STI V2 or not, it but it's quite hard.

I have STI V2 as mfg. date aug 1995-aug 1996. These were the last of the closed deck blocks, as the V3 was open deck. It may be possible that it came from a chassis with date just prior to Sep. 96, but was coupled with a later V3 engine on the assembly line and was an honest mistake on the part of the supplier. Then again, I usually don't give people the benefit of the doubt. I feel there are too many people in this world to waste time on any that may be suspect.

It also seems compression ratio on the V3 was lowered from 8.5 to 8.0:1. It would appear there were some other changes involved as I have the V3 listed as having more HP and torque than the V2. A turbo upgrade, perhaps? Something to make up for that compression drop...

Steve

Version II should have single bolt coils as well as only having the ribbs on the cam covers along the top (not the bottom like the BC/BF EJ20G).

humm, not quite sure to understand well the "Single bolt coil" thing.

I'll have detailed pictures of the engine this evening. So maybe it will be easy for you to tell if it's a STI V2 engine.

Also ... Aren't all the STI V2 blocks supposed to be Closed Deck ?

Yes, all V2's should be closed deck by definition (any further changes, I would assume, would require a nomenclature change). My sources state that open deck turbos started with V3 production.

Steve

Finally, could log on the forum !!

here are the pics

http://public.fotki.com/morgie/morgie/m ... ock_fredo/








The Yellow injectors were installed 2 weeks before the incident... 440cc side-fed from a ej20TT




Strangely, all the pistons are melted , except for the #2, wich looks like new !!

for a comparison use, here are the WRX 96 (EJ20G) Heads Invisible Throw was talking about.


Ribs up and down, with 2 bolts coil.

morgie: The above pic is the early EJ20G found on JDM Legacy's (BC/BF) 2bolt coils, grills on both sides, the pic of the Cover with just one set of grills and 1bolt coils are the 92~96 WRX EJ20G.

THE EJ20K V3/4 WRX has no grills and uses the waste spark setup.

the ver3 has cams and a VF23 turbo, which acconts for the lower compression and more power argument.

the ver2 motor has CAST pistons, the ver3 was the first motor to have true forged pistons, but both versions have closed decked blocks.