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Hey, thanks for taking the time to read this. I currently own two sentras. a 98 and 97. I want a spec-v pretty bad but I don't have the money to get a nice running one. So I figured with alot of work I might be able to get one that needs a motor and save big. I am not new to replacing motors but I am new to the 2.5L motor. So here's my question...

I was thinking about buying a 2003 spec-v with a bad 2.5 motor. The earlier 2.5 motors that are an exact replacement used engines are quite high 1500 or so. If I buy a newer Altima 2.5 motor like a 2007 or later the price drops to somewhere around 600-700 for a nice low mileage motor. My questions are this. Are the motors the same as far as bolt up etc? If so will I have to change stuff around to get this to work? Or won’t it work at all? What I am afraid of is buying a later motor and having things totally different like harnesses and computers, sensors in the wrong spot, etc…
As an example I bought a 1997 Sentra that needed a motor. I got another 1.6l engine that bolted up fine but I had to change a few things around. It wasn’t a big deal at all and in no time I had it running good.

Also are the later motors still having problems with the butterfly valve screws falling into the cylinders? What about the later pre cats? Are they still coming apart and destroying the motor?

Has anyone done this swap?


thanks
 

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im in to know the answer to this too when my qr gets up thur....... i no it will take some fab work chances are peopl go with the 3.5swap it seems to b more worth it than putting another 2.5 in
 

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Hey, thanks for taking the time to read this. I currently own two sentras. a 98 and 97. I want a spec-v pretty bad but I don't have the money to get a nice running one. So I figured with alot of work I might be able to get one that needs a motor and save big. I am not new to replacing motors but I am new to the 2.5L motor. So here's my question...

I was thinking about buying a 2003 spec-v with a bad 2.5 motor. The earlier 2.5 motors that are an exact replacement used engines are quite high 1500 or so. If I buy a newer Altima 2.5 motor like a 2007 or later the price drops to somewhere around 600-700 for a nice low mileage motor. My questions are this. Are the motors the same as far as bolt up etc? If so will I have to change stuff around to get this to work? Or won’t it work at all? What I am afraid of is buying a later motor and having things totally different like harnesses and computers, sensors in the wrong spot, etc…
As an example I bought a 1997 Sentra that needed a motor. I got another 1.6l engine that bolted up fine but I had to change a few things around. It wasn’t a big deal at all and in no time I had it running good.

Also are the later motors still having problems with the butterfly valve screws falling into the cylinders? What about the later pre cats? Are they still coming apart and destroying the motor?

Has anyone done this swap?


thanks
the 02-06 QR had the butterfly and kitty problems, the 07+ QR from what i hear doesnt have kitty problems, and they arent even equipped with 2nd runners to house butterflys....and if im not mistaken the sentras QR's are tuned differently than the altimas, so you might want consider 07+ spec v motors, they pump out 200 stock (02-06 = 175hp i believe) redline is pushed to 7K (6200 = 02-06) and the compression ratio is 10:1 (so i believe) (02-06 = 9.5:1)
 

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Just to clear a few things up in this thread... the 07+ Sentra SE-R motor's are NOT a direct swap and the 07+ Altima does not have the same QR as the 07+ Sentra SE-R's, as they are still rated at 175hp.
Whether or not an 07+ Altima motor is a direct swap, I'm not quite sure... someone else will have to chime in on that.
 

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i buildin my motor with a joa block (07 altima). only rhing that doesnt match up is the passenger side mount. but keep in mind the 07 block have oil squirter just look in my build thread
 

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Okay, I just replaced my motor in my 2002 Spec V, i used a 2007 QR25 out of a 07 altima, the only thing that is different is the front motor mount ( the one on the timing cover side ) they are interchangeable, just use your old motor mount. the 07+ QR's have better cams, and a higher compression and will push you about 200 HP i have done a few upgrades to mine and im getting 350+ WHP on the dyno. its a pretty easy swap too
 

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unless the altima motor wasnt touched between 06-07 then yes you can...however the difference between a 06-07 spec v qr25 definitely CANNOT be changed easily


if the chance that nissan didnt change the altima motor than youd need a new ecu, new mounts, and it would be dueable
 

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That's good news, anything needed from old motor besides pass. Mount?

What did you do about the header? Did you use the o2 style? Because the the 07+ uses 4 sensors
 

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yah but if your ecu only see 2 hen having 4 wont matter but im interested but my engine i was told was pretty new but when it gets up thur good to no i can go 07 altima
 

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It be nice to see the newer qr in a b15. Sure be faster than a stock b16. Good luck with this attemp. Hopefully it all works out
 

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Okay, I just replaced my motor in my 2002 Spec V, i used a 2007 QR25 out of a 07 altima, the only thing that is different is the front motor mount ( the one on the timing cover side ) they are interchangeable, just use your old motor mount. the 07+ QR's have better cams, and a higher compression and will push you about 200 HP i have done a few upgrades to mine and im getting 350+ WHP on the dyno. its a pretty easy swap too
200 out of a Altima qr? There are only rated 175 stock. The b16 spec qr has the 200.
 

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the 02-06 QR had the butterfly and kitty problems, the 07+ QR from what i hear doesnt have kitty problems, and they arent even equipped with 2nd runners to house butterflys....and if im not mistaken the sentras QR's are tuned differently than the altimas, so you might want consider 07+ spec v motors, they pump out 200 stock (02-06 = 175hp i believe) redline is pushed to 7K (6200 = 02-06) and the compression ratio is 10:1 (so i believe) (02-06 = 9.5:1)
07+ still has the precat issue. I know of at least one motor that was a precat failure in a B16 for sure. Heard rumors of others.
 

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ahh, i see, Nissan really likes running rich huh
 

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I was reading your thread and I was think about doing that too.. but didn't know where to start... tell me every little detail about your sawp...thanks..
 
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