EJ251 vs. EJ257?
10-13-2003, 04:02 PM
#1
Guest
Posts: n/a
EJ251 vs. EJ257?
The RS engine vs. the STi engine
just looking at my owner's manual here the only difference appears to be SOHC vs. DOHC, the turbo, and the compression ratio (10:1 on RS and 8.2:1 on STi)
with something that looks so similar on paper, why does it seem to be so difficult to get some big horsepower out of the EJ251 RS engine when it looks just like the STi power plant?
can someone please enlighten me?
thank you
-Mason
just looking at my owner's manual here the only difference appears to be SOHC vs. DOHC, the turbo, and the compression ratio (10:1 on RS and 8.2:1 on STi)
with something that looks so similar on paper, why does it seem to be so difficult to get some big horsepower out of the EJ251 RS engine when it looks just like the STi power plant?
can someone please enlighten me?
thank you
-Mason
10-14-2003, 12:21 AM
#2
Registered User
iTrader: (12)
Join Date: Nov 2002
Location: Reno, NV
Posts: 18,369
Car Info: 1993/2000/2001 GF4 mostly red
The EJ257 has a lot of advantages over the EJ251. The STi motor has forged internals, a partially closed deck, piston oil squirters, some extra block bracing, and some other things. The heads are quite different, even beyond the obvious sohc vs. dohc differences. Frankly, the bore, stroke, and cylinder geometry is about all the two engines have in common.
10-14-2003, 10:53 AM
#4
Registered User
iTrader: (12)
Join Date: Nov 2002
Location: Reno, NV
Posts: 18,369
Car Info: 1993/2000/2001 GF4 mostly red
Yes, but they all involve removing the engine from the car, doing some work to the block, and replacing the internals. Considering that the STi short block is available for as little as $1300, it's definitely better just to change to that.
10-14-2003, 09:03 PM
#6
Registered User
iTrader: (12)
Join Date: Nov 2002
Location: Reno, NV
Posts: 18,369
Car Info: 1993/2000/2001 GF4 mostly red
The short block itself won't make any power for you. In fact, it will make a lot less because of the compression ratio if you don't have a turbo kit. What the upgraded block does is let you safely make lots more power out of other mods. Probably the easiest way to get a lot of horsepower is to just do an EJ20 swap.
10-15-2003, 08:23 AM
#7
Guest
Posts: n/a
Is there anywhere i could go to find out about all the different Impreza engines and their specifications?
My owners manual is kinda leaving me in the dark.
Right now i'm stuck in that endless cycle
"The more you learn the less you know" - er something like that
Thank you for all your help, you're kept me from blowing my engine all over the freeway
My owners manual is kinda leaving me in the dark.
Right now i'm stuck in that endless cycle
"The more you learn the less you know" - er something like that
Thank you for all your help, you're kept me from blowing my engine all over the freeway
10-21-2003, 09:57 AM
#8
Guest
Posts: n/a
Hey Ban, do you know where one might find somewhere to purchase an EJ20 or possibly the STi? If the STi is going for under $1500 what do you think the EJ20 would go for and is that NEW? Sounds like a steal to me.....is the EJ20 block the same size and dimensons as all the other EJs?? I imagine the 2.0 doesn't include a turbo either...thanks!
-Potter
-Potter
11-11-2003, 10:00 AM
#9
Guest
Posts: n/a
www.rallitek.com These guys can get and if necessary install-modify, anything Subaru.
Ask for Sean.
Babu
Ask for Sean.
Babu
Thread
Thread Starter
Forum
Replies
Last Post
salvator_rizzo
Engine/Power - non turbo (All non turbo Imprezas)
6
08-06-2009 10:03 AM
Chocoholic005
New Aftermarket Car Parts For Sale
2
12-16-2008 08:46 PM
