Guide for identifying JDM 2.0 liters.

[lord flashheart]

so now that i have started my swap, i have been doing a lot of research and i figure i would make a thread with some about the differences in JDM turbo motors. first off the 20H 20R 206 and 208 are all twin turbos. i wont be covering that.

ok here we go.
the 20G is probably the easiest to identify.
was used in
-all turbocharged legacys until 1993
-all 5 speed WRXs until 1996 and automatic WRXs until 1998
-all STis until 1996

the 20G had 3 revisions or "phases" where they made mostly valvetrain changes.
some people think the 20G didnt come with a red intake manifold. i cant say for sure but i have seen a 20G with a red intake manifold but i dont know if it was painted or OEM. i think they came in the STi. but not the WRX.
some tell-tell signs of a 20G are:
intake pipe to the turbo doesnt run under the intake manifold like on the others.
the ingnition coil is not on the center of the intake manifold like the other JDM turbo motors.
the throttle cable is on the left (drivers side in USA) and the idle air control valve is next to it.
closed deck engine
the valve covers say '4cam 16valve' with horizontal lines
coil on plug
uses the "slanty" intercooler

here are some pics to help you
notice the ingnition coil is not on the intake and the intake pipe doesnt run under the intake manifold



and here are some valve covers from a 20G.



here is one more of the 20G



next we will cover the Ej20K
EJ20k was used in the Sti from oct. 1996 to oct 1998
all of the 20Ks have:
red intake manifold (usually the red paint is pealing)
smooth valve covers
ingition coil on the intake manifold
open deck engine
the throttle cable was moved to the left side (passenger side in the US).
and the idle air control valve was moved to closer to the throttle body. (this also makes it so
not all STi intercoolers fit do to the compressor bypass valve or blow off valve.)

here is some pics of the EJ20K



then their is the EJ205
engine importers offen sell these. as a JDM motor but its actually just a USDM WRX motor. it was used in:
foresters and wrxs and stuff.

it has
coil on plug
silver intake manifold
idle air control built into the throttle body
its also an open deck block.


notice the difference in the intake manifold and the power steering pump...


ok i think you all know what a ej205 looks like.


last is the EJ207
the EJ207 actually looks like the USDM turbo motors.
its used in
all STi models with the exception of the USDM which uses the EJ257
identifing this motor is a piece of cake.
it basically looks like a USDM EJ205 but with a red intake.
its a coil on plug
red intake manifold usually not faded and chiped
intagraded IACV
semi closed deck
'STi' on the inter cooler

pic.




if you have any info to add please do.
and all this is "to the best of my knowledge"
so it might not be 100% acurate please help

[Alucard]

I'll insert this information here, since I believe it can be more helpful than over in the Swaps/Conversions section.

Late USDM EJ25D:
Intake opens 6° BDTC.
Intake closes 50° ABDC.
Exhaust opens 54°/30° BBDC.
Exhaust closes 10°/10° ATDC.
Overlap 16°.
Intake/Exhaust lift 7.6mm/7.4mm.

Late JDM EJ20G/H:
Intake opens 8° BDTC.
Intake closes 52° ABDC.
Exhaust opens 52° BBDC.
Exhaust closes 8° ATDC.
Overlap 16°.
Intake/Exhaust lift 8.1mm.

Late JDM EJ20K/R STi:
Intake opens 10° BDTC
Intake closes 56° ABDC
Exhaust opens 56° BBDC
Exhaust closes 12° ATDC
Overlap 22°
Intake/Exhaust lift 8.2mm/8.3mm.

Early JDM EJ20H 8.5:1:
Intake opens 10° BDTC.
Intake closes 50° ABDC.
Exhaust opens 58° BBDC.
Exhaust closes 2° ATDC.
Overlap 12°.
Intake/Exhaust lift 7.6mm.

Early JDM EJ20G STi:
Intake opens 6° BDTC.
Intake closes 56° ABDC.
Exhaust opens 55° BBDC.
Exhaust closes 11° ATDC.
Overlap 17°.
Intake/Exhaust lift 8mm.

Early JDM EJ20G:
Intake opens 2° BDTC.
Intake closes 50° ABDC.
Exhaust opens 46° BBDC.
Exhaust closes 10° ATDC.
Overlap 12°.
Intake/Exhaust lift 7.5mm.

Early Euro EJ20G:
Intake opens 2° BDTC.
Intake closes 48° ABDC.
Exhaust opens 51° BBDC.
Exhaust closes 5° ATDC.
Overlap 7°.
Intake/Exhaust lift 7.5mm.

Early JDM EJ20D Cam Specs.
Intake opens 6°/4° BDTC
Intake closes 54°/56° ABDC
Exhaust opens 66°/36° BBDC
Exhaust closes 24°/16° ATDC
Overlap 30°/20°
Intake/Exhaust lift 8.5mm/7.5mm?

Try as I might, I can't find the proper lift specs for the 20D, so if anyone wants to insert that data, feel free. The specs are legitimate for the other cams, though. As you all can see, the 20K cams are the hottest to have ever been produced by Subaru in all the years of its Phase 1 EJ camshaft production.

The 20D cams interest me, as they seem to be the wildest in the N/A department. It would be cool to see them at work on a 2.2L or 2.5L block. (I request that this become a sticky.) You may notice that there are no "non-STi EJ20K" pair of cams. This is because the late non-STi EJ20K and late EJ20G are EXACTLY the same engine.

Late G, or "Common G", as I call them because they are more common than any other Phase 1 EJ20 turbo. In fact, unless you measure ports, cams, and valves, you must ascertain that you likely have a Common G. There are THAT many of them, and there are too many who falsely believe that the Common G in K form is a STi K when it isn't.

This being said, there were MANY changes in the heads from 89-93. ALL known STi EJ20G's during that time period had a closed deck block, while some WRX's did not (more closed decks were produced in this time). The metallurgy used in these early EJ20G's made the quite strong, ever stronger and more resistant to wear than their later counter parts.

The EJ20D/E and 22E/T variants also share this arrangement of tougher metals and were also highly reliable.

When the EJ20K/G/H/R line was produced, reliability took a drop, particularly in the internal bearing department. As a result, aren't as reliable as the older G's. Whatever Subaru did to those bearings from 94-98, it wasn't nearly as helpful as from 1989-1994. That much is certain. Not a speculation, just something people discovered a long while back. Now, what I HAVE discovered among those many things is that the bearings and rods from the old school G's and the EJ22E/T Version 1's are exactly the same, and so are those in the Version 2 EJ22E's. The JDM line in the mid 90's were all different, and thus not as strong.

Let's clear something up right here. There is no way that closed deck G's were unreliable compared to the K's. It has always been known and proven that the original EJ20G's were the strongest of all the Phase 1 EJ20 turbos to have ever been produced. Now the Common G's and H's blowing up, I would agree, since many of them had a 9:1 compression ratio, and were used during a time when most of the G's were considered to be the same when they were different. Better heads, the K has, but definitely not better reliability than the old school G's. If anyone tells you that an EJ20K block is as tough as the old school G, just, NO. At all. Ever.