Sentra Cams in 2.5 Altima?

[SER Wes]

I saw randomly posted that b15 sentra(02-06) ser/spec-v cams will work with the newest gen 2.5 altimas(06+ qr25). Is there any truth to this? Has anyone done it?

I know that b15 cams will not work in the b16 Spec-v with the high compression qr, but i am speculating that the high comp might have a different cam setup. I know it has a different head. I am wondering if they might work in a base SER though. If they work in qr altima, then there is a good chance.

Thanks in advance

[el_blacky06]

Its a great question, not even my mechanic could answer it. Supposely its possible but I have yet to see proof of that for the past 3 years

[QR25DE]

They will not work. While they may physically fit (unlikely), the timing will be off on both intake and exhaust due to the "redesign" of the motor. The valve springs are even different. I do not think most companies realize this as of yet and that's why nothing has been developed. You're welcome to get them and test them out though ! hahaha.

[el_blacky06]

Haha that would be an epic fail if it don't fit lol but in all seriousness, someone posted here about claiming to have upgraded cams on an altima coupe. Imma try to search for a bit to find out.

[el_blacky06]

fuel-injection-t469684.html

The dude claims he also has a stroker kit but no proof of charts or pictures watsoever. You could give it a try to see if it works tho

[mrodrig2]

They will not work. While they may physically fit (unlikely), the timing will be off on both intake and exhaust due to the "redesign" of the motor. The valve springs are even different. I do not think most companies realize this as of yet and that's why nothing has been developed. You're welcome to get them and test them out though ! hahaha.

Altering the timing is the whole purpose of replacing the cams. Different doesn't mean it won't work. You would obviously not just drop the cams in without wanting to dive into the computer.

[QR25DE]

They will not work. While they may physically fit (unlikely), the timing will be off on both intake and exhaust due to the "redesign" of the motor. The valve springs are even different. I do not think most companies realize this as of yet and that's why nothing has been developed. You're welcome to get them and test them out though ! hahaha.

Altering the timing is the whole purpose of replacing the cams. Different doesn't mean it won't work. You would obviously not just drop the cams in without wanting to dive into the computer.

Really, that didn't occur to me...

Cams MADE for the motor will work, not cams made for a slightly different motor with different compression, timing, different stock cams with different lifts and durations.

I know all about cams as I built a motor before with Crane cams for my Neon back in the day. If cams are going to be made to work they will need to be designed around this revision of the motor and not the 06 and earlier versions.

Again, while the cams *may* fit, they may not perform optimally (even with tuning) as they are not designed for this motor.

Here are the main differences between 07+ and 06 and earlier and the SPEC V versions.

1. Standard 06 and earlier valve springs are weak.
2. Standard 07+ valve springs are weak.
3. SPEC V 06 and earlier valve springs are preferred.
4. SPEC V 07+ valve springs are preferred.
5. 06 and earlier Balance Shaft is different that 07+. The balancer system has been moved back slightly from the crank pulley to a more central location in the block. This also means JWT's balance shaft removal kit for the 1st gen QR will not work.
6. 06 and earlier use a different spark plug than 07+.
7. The ECUs are different between 06 and earlier and 07+. -- Thus Uprev supporting 07+.
8. Power valve screws in the intake manifold may become loose and result in unstable idling or power loss in 06 and earlier. This is fixed for 07+.
9. A simpler, larger diameter single path resin intake manifold replaced the old dual path design. No more troublesome butterfly valves with screws that came loose and got ingested.
10. 07+ Revised piston crown shape to support a higher compression ratio of 9.6:1.(10.5:1 in Sentra SE-R Spec V.)
11. 07+ Revised cam shaft profile.
12. 07+ Reinforced connecting rods.
13. 07+ also has a higher rev limit.

The main things to be concerned about would be using cams designed for the 1st Gen in the 2nd Gen motor due to the different stock intake and exhaust durations. The after market cams are designed to be more aggressive than stock, not more aggressive than stock on a 2nd Gen. It's different.

If you want to try it go ahead and let us know the results. I'm basing this of what I know personally and what I have found online with research before I boosted mine. I abandoned this idea due to all the differences. Many sites that sell after-market cams usually mention *not compatible with 07+*. You would also need strong valve springs. With more aggressive cams the lift and compression on the springs may be too much for stock (depending on how aggressive you go) and cause the valve springs to snap. When that happens usually the valves will smash into the pistons cause the piston head to EXPLODE IN A FURY OF CRASHING AND DESTROYED ENGINE GOODNESS!

My opinion/conclusion: Wait until 07+ cams are made or get a company to custom make them for you.

This is what happened to my piston in my Neon with Crane 16 cams and Crane valve springs... should have replaced them with Crower springs but lesson learned:

Before:



After:





At least the rods were good... lol

[mrodrig2]

Long anecdotal story.

[QR25DE]

Either way the cams won't do much. They'll just change where the power curve is positioned. Since the motor is full of low end torque and makes the best power around 3800-4200 RPM I don't see why you would want to change this unless you're going to fully build the motor boring it out, larger pistons, ported head etc. This might be why most of the aftermarket parts for this motor are bolt ons. There aren't much gains and many people sinking money into a 2.5L Altima/Sentra to make it worth while to develop anything 07+ for it, especially at this point in time. If the older cams *worked* someone would have built it by now and people would have heard about it.

Even browsing the Sentra forums and other Sentra B16+ sites there is nothing for cams 07+. Most have come to the same conclusion.

It may be a long anecdotal story, but it's facts. If you'd like to read up on more stop by Nissan, get repair manuals and do some pretty basic Google and Wikipedia searches. They all have the SAME info. So my story isn't anecdotal at all, it's credible, factual, and scienfic(al)? lol.

If these fit and can proven they are optimal and work for this motor and valve springs can be sourced then go for it. Nothing has come up thus far.

[dldjros69]

SUCKS

[mik]

Long anecdotal story.

And your post is useless because he's right.
Thanks for coming out though. The 07+ QR25DE was a SIGNIFICANT redesign of both block and head. If you read stories about the life of Nissan's race teams using the engine you'll see why.

I'm trying to find the link with comparison pictures between the two generations. I'll post it if I can find it again.

Heres a quote from an email from JWT.

"We currently do not make any parts for the 2007+ Sentra with the QR25DE. Nissan made enough changes to the engine that none of the parts we make for the 2002-2006 QR25DE work. Nissan also changed to a Renault based 6-speed transmission with a different starter and a smaller transmission input shaft design which renders our early QR25DE flywheel and clutch parts not usable. We are looking into the possibility of making cams and flywheel and clutch upgrade. ECUs for all 2000+ models are still in development and it is likely going to be a while when a possible ECU upgrade for these models might become available."

Edit: Don't need the JWT links -- QR25DE provided them below.

Also, what JWT quotes below should probably be two separate statements. He's referring to the 02+ Altima engine in regard to the clearancing, not 07+.

[QR25DE]

Direct from Jim Wold Technology:

"DOES NOT FIT 2007+ SENTRA, ALTIMA NOTE: DUE TO THE MUCH LARGER LOBES, CYLINDER HEAD TO LOBE CLEARANCE MUST BE CHECKED AND CLEARANCED AS NEEDED."

The 07+ stock cams are DIFFERENT than the 06 and before stock cams. This is why after market cams will not work as well... same with valve springs.

http://www.jimwolftechnology.com/custom ... ?PartID=10

http://www.jimwolftechnology.com/custom ... PartID=501

http://www.jimwolftechnology.com/custom ... PartID=434

Thanks.

[SER Wes]

Thanks for the replys everyone.

The general consensus up to this point has been they Could work with a little modification(to the signal plate i believe). This came from someone parting out an 07+ specv engine and comparing the b16 and 15 cams. I would link you to the thread, but you know the rules.

I was really more interested to see if there was any significant differences between the the SER/altima cam setup and the specv. Which i have concluded no.