MR-series engine

[Ever Victorious]

Well, with the new Sentra being released, it's time to talk about the new MR-series engine that is going into it.

Someone should be following up shortly with a picture of the engine bay (I'm at work and can't download it for repost), but there are some new features about the design.

In an effort to increase interior room, the MR series switches up from the traditional 4-cylinder layout of IM on the rear and exhaust manifold on the front. The MR has the IM on the front, and the EM on the rear. This allows the firewall to be moved up several inches, and move the whole passenger compartment forward.

To keep the car quiet and retain the correct length of intake tubing, they actually route it towards the rear of the engine bay, under the mid-bay mounted battery, and to the front draw box.

Kinda neat from an engineering perspective. Not built for performance, but for economy and space.

I'll try to test-drive a new Sentra this weekend to give a full account of the Versa-vs-Sentra comparison.

[Eikon]

[The 240 kid]

Hmm.. they did the same in the Honda Fit. It makes the engine and bay look microscopic. I don't really like it, but I'm sure this motor probably is a little better off the line than my SR20. I'm interested to hear in your comparison to the Versa, but more importantly something else with a SR20.

[Eikon]

So the actual runners of the intake manifold go up over the top of the engine.. just below the plastic cover? I bet there more than a few companies out there looking to clean up that design (AEM, Injen, etc..)

I understand the desire for long runners in the plenum itself, but for some reason all the routing from the hood, down under the box on the right, then back to the MAF and stuff in the back... boy that's a lot of tubing to get air into that engine.

I am impressed that they finally turned that engine around... It just makes so much more sense to have the exhaust manifold on the back side of the engine.

Hopefully they did a nice job with sound deadening to keep that noise out of the engine bay. (Though from the couple reviews I've read.. .they did a spectacular job of keeping the car quiet on the road!).

[NSR_s30]

Interesting. Nice to finally see it.

[RED_DET]

The MR is a family of straight-4 all-aluminum automobile engines with variable valve timing co-developed by Renault and Nissan.

The MR20DE is a 2.0 L (1997 cc) version, the first in the family, bore is 84.0 mm and stroke is 90.1 mm. It was designed to use the XTRONIC CVT continuously variable transmission.

MR20DE 2.0-liter DOHC 16-valve 4-cylinder engine 140 hp @ 5,100 rpm 147 lb-ft of torque @ 4,800 rpm Emissions ULEV Continuously Variable Valve Timing Control System (CVTCS) Nissan Direct Ignition System Iridium-tipped spark plugs Electronic drive-by-wire throttle Drivetrain Front engine/front-wheel drive 6-speed manual transmission Xtronic CVT (Continuously Variable Transmission) Brakes 11.02" Vented front disc/rear drum brakes 4-wheel Anti-lock Braking System (ABS) Electronic Brake force Distribution (EBD) Suspension and Steering Front: Independent strut suspension Rear: Torsion beam axle with integrated rear stabilizer bar Front stabilizer bar Electric power-assisted steering

Curb Weights Manual transmission 2.0(2853) 2.0S(2907) 2.0SL (NA)Xtronic CVT 2.0(2897) 2.0S(2951) 2.0SL(2991)

[Renaissance'D]

From http://www.nissan-global.com/E...a.pdf