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Old 01-16-2012, 09:29 PM   #1
blackoutlegacy
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Default N/A Engine build help please

i Have a 98 legacy gt 2.5 n/a and i am building an engine for it. I only can find wrx parts.. I want to build n/a pistons, cams and a great bearing set. Does anyone have an suggestion of where i can find these parts... Any help is greatly appreciated.
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Old 01-17-2012, 11:55 AM   #2
Highflyr
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Use ACL race bearings got mine from racemart.com as for pistons just putz around ebay there's a ton of options for EJ25s and send the cams off to deltacam.com for grinding.
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Old 01-17-2012, 12:23 PM   #3
Raising Cain
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Depending on the situation the stock pistons can handle I think up to 300HP... Just did mine with factory 100MM pistons. Definatly send of the cams to Delta... I paid 500 to get mine done! and if you give the guys at Import Image Racing a call they can help with a lot of stuff...
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Old 01-18-2012, 04:39 PM   #4
GrundleJuice
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The stock pistons can handle cylinder pressures high enough to make lots of power, but as soon as any heavy detonation occurs, the ring lands trends to give up. If you are going to try to make tq and spin to redline our above frequently quality forged pistons are the only reliable way to go.
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Old 01-18-2012, 04:51 PM   #5
ballitch
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The first question asked should have been "what's your budget", since that determines just about everything. BTW, what is your budget, what are your goals, and what is the car going to be used for?

If I were you, I would source a rebuildable EJ251/3 block, rebuild it, and put off the shelf 11.5:1 CR pistons in it. Then I would send the cams to Delta for a mid-high rpm range power grind. After that, I would look into some sort of engine management, Emange or even Megasquirt.

But this all depends on what you want from the car power-wise, and how much money you are willing to throw at it to get there.


~Josh~
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Old 01-18-2012, 05:14 PM   #6
ciper
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I am going to make a bunch of assumptions that are most likely true

Since you are rebuilding it for your 98 GT its an EJ25D. So the headgasket was leaking. You need to look at cleaning up the mess left behind before thinking of performance upgrades. The block and heads should both be decked. The cylinder wall of the leaking gasket will need to be cleaned up since water sucking into the cylinder displaced the oil. This most likely means different size of pistons. If the bearings were damaged because of heat the valve seals also most likely need replaced. If it made a milkshake the cams will likely have damage on them. To do a proper rebuild you'll need 600 in gaskets/bolts/seals/etc. I could go on.

In the end it might be in your best interest to do an Ej20 swap. The labor would be similar (since it wouldnt need a rebuild), you'd have more power and it would be reliable for another 200k miles.
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Old 01-18-2012, 11:04 PM   #7
watchdoc
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Quote:
Originally Posted by ballitch View Post
The first question asked should have been "what's your budget", since that determines just about everything. BTW, what is your budget, what are your goals, and what is the car going to be used for?

If I were you, I would source a rebuildable EJ251/3 block, rebuild it, and put off the shelf 11.5:1 CR pistons in it. Then I would send the cams to Delta for a mid-high rpm range power grind. After that, I would look into some sort of engine management, Emange or even Megasquirt.

But this all depends on what you want from the car power-wise, and how much money you are willing to throw at it to get there.


~Josh~
"off the shelf" NA pistons are very expensive. Custom pistons are about the same price. Then you get to deal with the issues of forged pistons. Despite the high compression, it will still be slow compared to a turbo subie. Have your stock pistons coated if you want some increased durability.

Even delta cams for the DOHC subie are expensive and the results are so so.

Do a stock rebuild with high quality parts and spend the extra money on "driveability" and handling. The reliability and throttle response of the NA cars will ensure many fond years of happy ownership.
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Old 01-20-2012, 12:42 PM   #8
blackoutlegacy
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Thanks everyone, no my engine is still running, no blown gaskets, or anything.. But its at 202,000 miles and i can hear a random rod knock thats intermintant.
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Old 01-20-2012, 02:46 PM   #9
ballitch
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98 cam'd EJ251
Wrx Tranny,slowr than ish

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Quote:
Originally Posted by watchdoc View Post
"off the shelf" NA pistons are very expensive. Custom pistons are about the same price. Then you get to deal with the issues of forged pistons. Despite the high compression, it will still be slow compared to a turbo subie. Have your stock pistons coated if you want some increased durability.

Even delta cams for the DOHC subie are expensive and the results are so so.

Do a stock rebuild with high quality parts and spend the extra money on "driveability" and handling. The reliability and throttle response of the NA cars will ensure many fond years of happy ownership.
Of course forged pistons are expensive, yes, they also have different requirements for their use. Cams cost money too, no surprise, and the gains aren't "so-so".

OP, ignore what I said about forged pistons, and cams since they don't do $hit, find yourself an EJ251/3 block and rebuild it. Throw it under your stock heads, this will increase your compression ratio from the 9.7:1 it is now to about 10.4:1 This won't require you to use premium fuel, but mid-grade would be advisable.


~Josh~
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