2008 MS3 CBM

AtomicSpeed3

Greenie N00B Member
Hello! Back in 2008-2010, I used to have a 08 MS3 in black. Loved the shit out of it and then had to sell it for personal reasons. Many years later, been looking around for another MS3 to fill the void.
Finally, found a Cosmic Blue Mica (which is the original color I wanted!) on FB marketplace for $600. The engine block has a nice hole from #3 rod so I was planning on swapping it with either another 2.3 or most likely do a 2.5 hybrid swap. I don't plan on going crazy with this, just a nice reliable DD.

Used to be active on Mazdas247 as BlackJack and now back on here. Looking forward to all the help I can get. I've been a GM World Class technician for 15 years so swapping engines don't scare me anymore haha.
Thanks!
 

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2.5 swap is an emergency thing to get you back up and running temporarily; it won't hold up.
I'd save up a bit and do a built 2.3 engine, but you can keep the stock manis and turbo until you're ready to upgrade those.
 
What's your budget looking like? I have my 2012 up for sale (site membership required to view). Comes with a working engine AND a spare block/head.
 
What's your budget looking like? I have my 2012 up for sale (site membership required to view). Comes with a working engine AND a spare block/head.

4k is my budget. I have a 2012 cruze, clean and in great shape that i will sell once the build is done.

I found a junkyard 2.5 for 225, so with the extra money, I was going to strip it down and replace the oil/water pumps, timing chain, install new forged rods and forged pistons, and clean up the 2.3 head to slap on. Like I said, not looking to make crazy power on this, just subtle enough to get me through. Bad idea or just find another 2.3 engine?
 
2.5 on reduced boost (spring pressure k04) will probably be fine as long as you don't race it around until you can build a 2.3. If you want to build the 2.5, that's fine too, just know that you'll have a reduced RPM due to the drop in VE of a stroker motor at higher revs (I went 2.0 for this reason). Also, a small turbo like the K04 is more likely to spool too fast and overshoot even spring pressure due to inertia, which can be...problematic.

Food for thought.
 
2.5 on reduced boost (spring pressure k04) will probably be fine as long as you don't race it around until you can build a 2.3. If you want to build the 2.5, that's fine too, just know that you'll have a reduced RPM due to the drop in VE of a stroker motor at higher revs (I went 2.0 for this reason). Also, a small turbo like the K04 is more likely to spool too fast and overshoot even spring pressure due to inertia, which can be...problematic.

Food for thought.

Thanks for the reply. I'll be honest, I've been using chatGPT to help me out and plan for this build. So far, the build is around $1900 and a 2.3 drop in from texas JDM is $2000. I want to try to keep this long term. I don't ever plan on racing this, maybe a BNR S1 turbo in the future. Would you recommend I look into a 2.0 engine build?
 
No, theres additional considerations for a 2.0; as far as I know, I'm the only one doing one (and it should probably stay that way unless you're planning on doing autox/road racing type stuff).

Stick with a standard 2.3 with upgraded rods and pistons and you'll be fine. Hell, even a bone stock 2.3 (out of a speed, not a cx7) can handle upwards of 400 WHP.
 
i wouldnt trust chat gpt for info about these cars, all of the knowledge is here and much of it is restricted to members. AI would be learning from facebook and reddit and those guys dont have any idea what is going on.

BNR s1 is a direct replacement for the stock k04 so i dont know why you would buy one. if you are ever going to upgrade the turbo then you shouldnt build a 2.5
 
This was a factory stock engine with EFR 6758, PNP intake mani, CPE TMIC and some WMI, self tuned; about 370 WHP and plenty fast:

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No, theres additional considerations for a 2.0; as far as I know, I'm the only one doing one (and it should probably stay that way unless you're planning on doing autox/road racing type stuff).

Stick with a standard 2.3 with upgraded rods and pistons and you'll be fine. Hell, even a bone stock 2.3 (out of a speed, not a cx7) can handle upwards of 400 WHP.

Gotcha. Thanks for pointing me in the right direction. I was led that the 2.5 engine is more reliable so I had thought that a hybrid 2.5 swap with forged pistons and rods would make sense as far as reliability wise.

i wouldnt trust chat gpt for info about these cars, all of the knowledge is here and much of it is restricted to members. AI would be learning from facebook and reddit and those guys dont have any idea what is going on.

BNR s1 is a direct replacement for the stock k04 so i dont know why you would buy one. if you are ever going to upgrade the turbo then you shouldnt build a 2.5

I typically take chatGPT with a grain of salt, it's just there to help get decent information. But thank you for the information. I knew becoming a member and posting would help get more information. Currently looking into 2.3 drop ins now. I'm wondering if I should find a short block and build it. Trying to stay within 2k-2500 budget for the engine itself.
 
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Gotcha. Thanks for pointing me in the right direction. I was led that the 2.5 engine is more reliable so I had thought that a hybrid 2.5 swap with forged pistons and rods would make sense as far as reliability wise.
It's generally pretty easy to say that any NA motor is going to be more reliable than a turbo one....But if you bolt a turbo to that "reliable" NA motor, the roles are going to be reversed, as the factory turbo motor was built for boost but the NA one was not. Big, big difference there.
 
@Enki Makes sense. Trying to find a short block for cheap and then I can build it this way. Otherwise, a drop in will have to do and I can slowly rebuild the original motor.
 
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