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Old 06-10-2008, 09:40 PM   #1
AWDrifterz
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Default JDM EJ25 vs USDM EJ25 (Both MY98)

hey guys, I wounder if there is any diffrence between the JDM EJ25 and the USDM EJ25?? I know that both have DOHC, but what about the internals? I mean can I use USDM EJ25 parts to rebuild a JDM EJ25??

I'm getting one for dirty cheap, and I wounder if it's possible to rebuild it?
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Old 06-10-2008, 09:54 PM   #2
parkes
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The parts should interchange, if im correct, the JDM moter was tuned for more power and didnt have any major diffrences, other than of course the ECU
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Old 10-30-2008, 03:57 PM   #3
Odyknuck
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The JDM motor will not have the EGR provision
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Old 10-30-2008, 09:55 PM   #4
elislider
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do you mean a non-turbo (NA) JDM EJ25? '98 didnt have any turbo in the usa... or maybe im reading too far into his question. you dont see many JDM EJ25 NA motors around the usa...
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Old 10-31-2008, 12:06 AM   #5
Matt Monson
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You're new around here aren't you? I can think of half a dozen importers off the top of my head that stock DOHC JDM EJ25 NA motors. With the head gasket issues of the DOHC's the JDM engines are a very popular cheap plug and play replacement engine for people. There's thousands, maybe even tens of thousands, of cars running around this country with those engines in them. I've got one sitting in my garage.
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Old 10-31-2008, 05:48 PM   #6
ciper
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Odyknuck is right. The only important difference between the long blocks would be a missing EGR port that can be tapped if needed.
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Old 11-02-2008, 02:35 PM   #7
elislider
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Quote:
Originally Posted by Matt Monson View Post
You're new around here aren't you? I can think of half a dozen importers off the top of my head that stock DOHC JDM EJ25 NA motors. With the head gasket issues of the DOHC's the JDM engines are a very popular cheap plug and play replacement engine for people. There's thousands, maybe even tens of thousands, of cars running around this country with those engines in them. I've got one sitting in my garage.
well ive only been on here for about a year, but thats not related. im only saying personally i havent seen hardly any discussion of JDM NA engines... but maybe i just havent been looking in the same places as you or others. *shrug*
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Old 11-04-2008, 01:00 AM   #8
Drakien
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My engine seized up so I ordered a used JDM motor from Attarco. All you have to do is swap the intake manifold out and it takes care of the EGR valve. I would not recommend buying a motor from Attarco though. I got 2 bad engines from them. http://www.youtube.com/watch?v=VUFweRCMPzQ That is what they were doing. And they will either replace the engine if its bad or refund your money, but be out shipping and labor costs.

But from what I have seen in person, there is no difference.
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Old 11-04-2008, 12:04 PM   #9
Matt Monson
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Quote:
Originally Posted by elislider View Post
well ive only been on here for about a year, but thats not related. im only saying personally i havent seen hardly any discussion of JDM NA engines... but maybe i just havent been looking in the same places as you or others. *shrug*
A good rule of thumb is that if you don't know for sure just don't say anything. Over in the NA forum we've discussed them a lot over the years and anyone in the industry knows about them. Until very recently putting a direct replacement JDM engine into a US car never got discussed as a "conversion" because technically it is not.
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Old 11-05-2008, 09:24 PM   #10
elislider
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i dont think i was out of place in saying what i said at first. ive seen way more swapped NA->turbo subarus than i have JDM NA engines. thats simply what ive seen. i know a lot of subaru guys and ive been to meets and shows and i think ive seen maybe 1 NA JDM engine. i dont hear much talk about them. not to say they dont exist or something. i just hadnt heard much about them, thats all. i will agree i havent read in the NA section much, and only recently started browsing the conversions section because im doing a conversion myself. dont appreciate being flamed. im not propagating misinformation or something. i didnt say the OP asked a stupid question, and i didnt call the OP a stupid n00b or something.

what i do know had already been said (so i didnt feel like reiterating), that generally the blocks have very few differences and differences between similar engines in similar years (when talking about mid to late 90's engines) tends to be with the intake manifold and the fuel system, partly because of the tuning differences between JDM and USDM and partly because of OBD/OBD2 requirements in the USA
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Old 11-08-2008, 01:25 PM   #11
west_minist
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Matt, are these the EJ25 running 10.7:1 compression with AVCS?

Last edited by west_minist; 11-09-2008 at 12:30 AM.
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Old 11-08-2008, 02:12 PM   #12
996Cabby
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I took one of these JDM NA EJ25 motors apart for it's shortblock and noticed that the pistons on the 97 JDM model I got had different pistons than the EJ25 engine in my 98 LGT....the USDM ones were dished , and the JDM ones were flat with the 4 machined spots in them for valve clearance....so I am assuming slightly higher compression although I can't find anything on paper stating it did.........this engine is the version with the coil-pack sitting on the passenger backside of the plenum... JFYI
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Old 11-08-2008, 02:17 PM   #13
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Ok. That seems to be the 98 into the 99 version, but for sure the 99-00 model. The rev limit on those motors were 7000+rpm.

Did that model came with variable intake runnings?

Where can you get those short blocks from. WOuld love to upgrade my EJ20R
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Old 11-08-2008, 07:18 PM   #14
996Cabby
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really? I though it was older as it had the older timing belt tensioner design,.....that's good news at least...but no it did not come with variable intake runners.......

ps...most JDM parts importers have them...
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Old 11-08-2008, 11:34 PM   #15
west_minist
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Ok,You have the older model then. Well I emailed the imported stated here.

Did the exhaust came with individual runners?

From a littler research, it does not seems to much difference between the Pre/post 2000 versions, except head difference. I wonder if the heads would bolt up. I guess it ends back up like the EJ20 heads on the EJ25 short block. I guess I have to sell my cosworth head gasket.

http://english.auto.vl.ru/catalog/su.../1997_9/28315/
http://english.auto.vl.ru/catalog/su.../2001_5/28458/

Last edited by west_minist; 11-09-2008 at 12:30 AM.
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Old 11-14-2008, 03:02 PM   #16
kerberos824
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This will probably be considered in the wrong area of the forums, but since this is what I'm considering doing I thought I'd start here. I just picked up a Forester (I know, not an Impreza) with the phase I ej25 and I believe it has the dreaded head gasket issue. Not really sure yet, doesn't have any of the tell tale signs, other than a wandering heat gauge, and I haven't done the chemical test for exhaust in the radiator, although I can't smell any. Picked the car up for 2000 under value, and knew that it was too good to be true. What I'm really curious about is if anyone here knows anyone in the North East (I live in the lower Hudson Valley of NY) who will do a swap between either a JDM or a USDM engine. Any help or points in the right direction would be greatly appreciated. Thanks.
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