02 Maxima crankcase pics

[Papa Bear]

Originally Posted By: wavinwayne
Nice pics. Thanks for posting.


Edit Reason: realized my logic was flawed. That never stopped me......

_________________________
Silence is golden, but duct tape is silver.
Dust tape over the mouth is silver and golden

 

[donz26]

VQ's rule!!

I managed 24 mpg in my Maxima on a 1800 mile road trip to Texas last month.

 

[Lethal1ty17]

Originally Posted By: donz26
VQ's rule!!

I managed 24 mpg in my Maxima on a 1800 mile road trip to Texas last month.


for interstate driving you should be getting better than 24mpg. even speeding with the ac on full blast.

i drive a 3.0L 2001 Eclipse V6 and managed 28mpg speeding, before i even had my exhaust put on, which probably adds another mpg.

 

[asiancivicmaniac]

Yeah, I'm confident if I do pure highway that I can get into the upper 20s, but I rarely go on such long trips.

 

[ls1mike]

I was going to say you should be doing better than that.
I get about 28 in the Buick.

Looks really nice and clean in their. Any idea what oil the previous owner ran?

 

[asiancivicmaniac]

No idea what was used in it and how long the intervals were up to 79k miles when I bought it.

I was searching for a car for over a month and every one that I had my eye on was either sold before I got to it or misrepresented by the ads. Found this one sitting on a third rate used car lot. Tried to get it for $6500, but the guy said he wouldn't go below $7000 (forgot exact numbers but it was listed for $8500 or something like that) and that was only because it was sitting on the lot for 6 or 7 months and he needed to sell it, but not for less than what it costed him. Fell in love and from that day on I just felt like it was meant for me and seeing the cleanliness of the engine makes be feel even better about it.

 

[The Critic]

Engine looks clean.

Did you have to remove the intake manifold in order to access the three rear plugs? I think you have to do that in order to replace the plugs on our Altima V6, and I am certainly not looking forward to that job.

 

[asiancivicmaniac]

Yeah, I had to take off the intake manifold. It turned a 10 minute quickie to change the plugs into a three hour chore. My back was sore the rest of the day from bending over the whole time. The valve cover wasn't hard to do either.

 

[440Magnum]

I just realized that thing has non-roller contact between the cam and follower! I didn't think anything but the Jeep 4.0/2.5, the SBC in trucks, a few little 4-bangers, and the Rover v8 were made that way after the early 90s.

 

[asiancivicmaniac]

Originally Posted By: 440Magnum
I just realized that thing has non-roller contact between the cam and follower! I didn't think anything but the Jeep 4.0/2.5, the SBC in trucks, a few little 4-bangers, and the Rover v8 were made that way after the early 90s.


What does that mean for those who don't speak gear head?

 

[Lethal1ty17]

meaning the camshaft pushed the valves open directly i beleive. here is a pic of my mitsubishi 3.0L with rollers. see the silver wheels towards the middle?

 

[asiancivicmaniac]

Is one better than the other or are they just two different ways to do the same thing equally as well?

 

[ls1mike]

Roller is nice, less wear, quieter. Flat Tappet (some folks call it a slider)works well and has for years, but give my a roller any day. Just becuase the motor is a flat tappet motor doesn't make it prone to wear. I put lots of hard miles on flat tappet 2.2 Trubo cars, running hight boost.
Overhead cam Roller from a 2.2 Mopar turbo

in this case the cam spins, "rolls" the roller in the rocker arm(I have heard it refered to as follower in the Turbo Dodge crowd)the rocker arm pushes on the "lifter" or in this case what is called a hydraulic lash adjuster and opens the valve.

Flat tappet

Flat tappet works the same, just no roller.

 

[asiancivicmaniac]

Thanks for the pics. I was wondering why I didn't see any springs.

 

[ls1mike]

Actually the rocker arum pushes on the valve the lash adjuster does just what it says. It is basically the pivot point for the rocker arm. Some cars like the DOHC above don't even have the rocker, just a lobe hitting the lifter.
I labeled this one. Makes it easier to understand.

 

[440Magnum]

Originally Posted By: ls1mike
Roller is nice, less wear, quieter. Flat Tappet (some folks call it a slider)works well and has for years, but give my a roller any day. Just becuase the motor is a flat tappet motor doesn't make it prone to wear. I put lots of hard miles on flat tappet 2.2 Trubo cars, running hight boost.
Overhead cam Roller from a 2.2 Mopar turbo


All true, but I would add a couple of other things. Roller cams sap WAY less horsepower. That's why Ford rollerized the 302, and Chrysler rollerized the 318 and 360 way back in the 80s- the efficiency gains were significant. Really don't know why Chrysler never bothered to rollerize the 4.0, except that being a lower-revving torque engine it could get away with softer valve springs that also suck less power. That, and they were "just about to end production" of it for at least 6-7 years before they actually did

The other big difference is that roller cams allow MUCH more aggressive valve opening/closing rates, so you get the performance of a long-duration cam profile without the idle roughness and inefficiency of a high-overlap cam profile. It lets you "de couple" overlap and duration somewhat by using aggressive ramps. If you use too aggressive a ramp on a flat tappet, the edge of the lifter will eventually dig into the ramp of the cam. Bigger diameter lifters help (which is why old Chevy engines always had to suffer from more overlap for the same duration than AMC, Ford and Chrysler engines which used larger lifters), but only up to a point. Roller takes it to another level entirely.

 

[Gary Allan]

Quote:
Really don't know why Chrysler never bothered to rollerize the 4.0, except that being a lower-revving torque engine it could get away with softer valve springs that also suck less power.


Wow!

I've been asleep!!

They rollerized the 4.0 before sending it off to never never land? I've had roller rockers since somewhere in 50k range, but they managed a roller cam and lifters?

 

[440Magnum]

Originally Posted By: Gary Allan
Quote:
Really don't know why Chrysler never bothered to rollerize the 4.0, except that being a lower-revving torque engine it could get away with softer valve springs that also suck less power.


Wow!

I've been asleep!!

They rollerized the 4.0 before sending it off to never never land? I've had roller rockers since somewhere in 50k range, but they managed a roller cam and lifters?


I think you missed the "never" in my post.

Seems like it should have been (relatively) easy since the Chrysler "Magnum" v8s basically used roller versions of an AMC valvetrain. I suspect the hold up was that it would have required a casting change to get lifter alignment guides down in the pocket in the block in the 4.0, whereas on the v8s it could be a bolt-in piece that sits in the lifter valley. But even then, you'd think that they could have used paired-and-crossbarred lifters like aftermarket roller cams for big-blocks do. Maybe that wasn't considered durable enough for factory build. Who knows?

 

[SLCraig]

Looks good. Probably about what mine looks like inside. Spying through the fill hole did not appear too bad inside at all. The P.O. never checked the oil, but he was dilligent about getting it changed at 3k mi (conventional)

As for the plugs, they don't look too bad actually. They look about the same as the ones I took out of mine. It was still running good on them, I just wanted to change them since they had 100k miles. (their specified interval for change)

 

[asiancivicmaniac]

If you ever take off your valve cover, post a pic or two. Kind of curious what other's look like. Saw a few on the maxima forum that looked varnished. And the Nissan vg's I've seen look varnished as well. Was starting to think it was typical of higher mileage Nissan's.

The new plugs seem to improve mid-upper range power. Feels more responsive and smoother. Still have yet to see if it improves fuel economy.