2008 Honda Accord V6 engine details
December 4, 2007 by Alborz Fallah
Although Honda is among the leaders in hybrid technologies, the Japanese manufacturer has put practicality above PR. The 2008 Honda Accord, set for release in February 2008, is not a hybrid. It’s better.
The Thai-built Honda Accord uses a 3.5-litre, 200kW-plus SOHC V6 that utilises Honda’s unique, high-tech Variable Cylinder Management (VCM), which means the new Accord can switch between six, four or three cylinders depending on road speed and load conditions.
The system is broadly similar to the one found in the Chrysler 300C but with an additional setting. The system will not only help bring fuel consumption down to a four-cylinder equivalent but will subsequently reduce emissions.
The system works by using all six cylinders during acceleration or high load, and seamlessly switching to four or three cylinders when cruising on the highway or driving at very low speeds (e.g. traffic jams). According to Honda, drivers will not be aware of the automatic switching.
The company says it’s the automotive equivalent of having your cake and eating it too! More details – including fuel consumption, we hope – are expected before February.
Honda released the following regarding the operation of VCM:
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How it works
During start-up, acceleration or when climbing hills – any time high power output is required – the engine operates on all six cylinders. During moderate speed cruising and at low engine loads, the system operates just one bank of three cylinders. For moderate acceleration, higher-speed cruising and mild hills, the engine operates on four cylinders.
With three operating modes, the VCM system can finely tailor the working displacement of the engine to match the driving requirements from moment to moment. Since the system automatically closes both the intake and exhaust valves of the cylinders that are not used, pumping losses associated with intake and exhaust are eliminated and fuel economy gets a further boost. The VCM system combines maximum performance and maximum fuel economy – two characteristics that don’t typically coexist in conventional engines.
VCM deactivates specific cylinders by using the VTEC (Variable Valve-Timing and Lift Electronic Control) system to close the intake and exhaust valves while simultaneously the Powertrain Control Module cuts fuel to those cylinders. When operating on three cylinders, the rear cylinder bank is shut down. When running on four cylinders, the left and centre cylinders of the front bank operate, and the right and centre cylinders of the rear bank operate.
The spark plugs continue to fire in inactive cylinders to minimize plug temperature loss and prevent fouling induced from incomplete combustion during cylinder re-activation.
The system is electronically controlled, and uses special integrated spool valves that do double duty as rocker-shaft holders in the cylinder heads. Based on commands from the system’s electronic control unit, the spool valves selectively direct oil pressure to the rocker arms for specific cylinders. This oil pressure in turn drives synchronizing pistons that connect and disconnect the rocker arms.
The VCM system monitors throttle position, vehicle speed, engine speed, automatic-transmission gear selection and other factors to determine the correct cylinder activation scheme for the operating conditions. In addition, the system determines whether engine oil pressure is suitable for VCM switching and whether catalytic-converter temperature will remain in the proper range. To smooth the transition between activating or deactivating cylinders, the system adjusts ignition timing, drive-by-wire throttle position and turns the torque converter lock-up on and off. As a result, the transition between three-, four-, and six-cylinder operation is unnoticeable.
Print it: 
What the? SOHC? Why?
Wikipedia says Ford are working on a Boss V8 that will shut off 4 cylinders. So, wonder will that be the future of engines?
this is really old technology. the funny thing is only now is it being put to a really usefull purpose.
if you remember even ford had a version of switching off cylinders they brought out in ‘98 with the AU’s where they were sprooking you could drive with a busted radiator hose.
not for the same purpose as this but in a nut shell it is the same theory but for a different purpose.
the main thing with this system as it becomes more popular among manufacturers is who does the best job of having the transition where it is actually seamless.
it will be like Auto boxes all over again. you have some manufacturers who just have some clunky boxes and you have some that really do have a silky smooth one like the ZF6.
this time you will have some that have clunky noticable transition periods and others where it truely isnt noticable.
you would expect Honda to be the latter.
I would have thought power would have been much higher than the estimated 200kW from tis new 3.5 V6, considering my current 3.0 V6 Accord has 177kW. I would have expected at least 220kW.
This may be “old” technology but so is ABS – doesn’t mean it’s a bad thing just a good thing continually improved. If Honda are doing this they will make sure it is the best darn cylinder shut down system available. When Honda developed their first diesel engine it was (and probably still is) the best available.
its a nice V6 engine , might sound out dated or what ever SOHC and so on, but still its HONDA and its as good quality as TOYOTA , very reliable and high tech “in a way” , not mechanically but ECU wise “sofware wise” “firmware vise”
But again i am pushing the point here , the INLINE SIX engine is the best.
and ps: its INLINE so it doesnt need balancing , so even if you just have 3 pistons working instead all six , you’ll get more torque than a typical 2.3L 4 cylinder car.
Why did they chose SOHC design? , why not DOHC x 2 = QOHC ?
hmm 200kW? why isnt anybody mentioning the TORQUE?
again i go for the new FG , 409Nm on RON95 , awsome, and at just 3250rpm.
198kW/409Nm on RON95 , 205kW estimated and over 410Nm on RON98 from a naturally aspirated Australian designed and patented INLINE SIX 4.0Litre DOHC DVCT engine.
ps: on my AUII i broke the hose on purpose in 2005 , and it actually did run on 3 cylinders and let me tell ya i felt as if there was no power loss , at least the smoothness of the engine power/torque delivery. It acted as a typical 4 cylinder I4 car + with no water in the block just air and oil cooling;)
At the end of the day we could re-program the Falcons I6 and V8 engines to do the same , shut down a few INJECTORS and just run V4 , V6 or full V8 ;)
Sam
and ps: you expected 220kW? yea but at 7000rpm ;) vs Fords I6 that makes over 220kW “mechanically” at just 6000rpm … de-tuned to 191kW on RON91 for every day use.
And remember all I6 engines are restricted , from 200kW/440-450Nm + to under 200kW/400Nm as usual.
Again i expected to hear something more intelligent , like “I EXPECTED AT LEAST 380NM OF TORQUE” and NOT “220kW of power”
something that people dont understand is at which RPM the peak torque and power is made…
seriously , no V6 or I6 out there matches the Falcons I6 , at least from EF/EL/AU/BA/BF/FG
no joke.
How does a Chrysler 300C 3.5L V6 sound like being beaten by an all falling in to pieces EF Fairmont 4.0L?
hmmmm think about it. and once more the BA and BF/BF2 make 360Nm of torque at just 1500rpm;) thats from a stock De-tuned final product from the factory the stock 4.0L DOHC.
give it the mild cam , ECU tune , extractords from the block – back , and you get 500+Nm from a stock I6 and over 250kW.
And it will still be economical + its RWD vs FWD.
end of story.
Amazing how everything becomes a Ford Vs Holden discussion
Yeh, but how much fuel does the Falcon suck?
…..The Falcon six sucks less fuel than the Commodore six
Sam/BFII/etc, why do you keep posting your BS on this site? And I’m pretty sure the old M3 6 is a far better engine than the Falcons, just to name one.
I’m not sure if this VCM is yet another Honda gimmick to make their engines seem better than they actually are. Toyota’s 3.5 Dual VVTi offers class-leading performance and yet relatively economical. A head-to-head comparison with the Aurion should show who’s really the best.
One big reason for SOHC is not that it is old tech, SOHC actually weights a lot less than DOHCs do, and can control just as many valves per cylinder.
best ni power tapi minyak jimat
macam ek4 aku
myvi aku jimat minyak jugak