The Temple of VTEC - Honda and Acura Enthusiasts Online Forums > Legend (RL) Refreshed in Japan - 6AT is confirmed, in-wheel silencer is something new >

bOOgiZ wrote:
owequitit wrote:
bOOgiZ wrote:
owequitit wrote:
bOOgiZ wrote:
owequitit wrote:
osaze wrote:
I agree! Acura is long overdue to overhaul its engines with infinite valve timing on both intake and exhaust valves and six speed transmissions throughout the whole lineup. I can�t believe that Acura allowed Ford to build a screaming 306 HP V6 with infinite timing and DOHC to booth! Again, it seems like Acura is doing with it thinks is best for customers in its own tardy and listless fashion.

Don't you find it odd that for such an out of date pile of metal, the J series is making as much power, and as much torque, and making similar MPG numbers out of the same displacement?

That makes me curious as to what advantage the new Ford V6 really has... It needs all that tech to MATCH an 11 year old Honda engine?

The advantage is that it is a Ford V6 starting out with 300+hp and DOHC. The J series surely didn't start out with 300hp, but has been updated/stretched out over 15 years. With the amout of OEM and aftermarket support for Ford and the mustang, we will surely see what a few years will do for Ford's V6 engine.

The problem for Ford, and the others in a similar position, is what happens when Honda actually opens up the ports (the J series ports are pretty small by comparison), puts DOHC with VVT, puts dual stage IM's on everything, and makes all of the other changes they have learned in the last 13 years? Where does that put Ford, GM, Chrysler etc in relation to engine tech? Right back at the back of the pack.
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the real problem is that Honda had just about all that and more with the DOHC C32 .. they introduced a neutered j series with simpler tech for the masses and made updates as if they are breaking new ground..... they should have incorporated DOHC on the J series..at least for Acura models long ago. Honda spent 13 years on the J series to learn how much VCM sucks.

You probably need to recheck your facts.

1) The DOHC C32 was a highly exotic, high priced, low production engine in the NSX only.

The version of the C32A that was widely implemented in the Legend and TL, and the C35 derivative in the RL were SOHC.

This version of the C32 topped out at 230HP, a value which the J series surpassed long ago, in more pedestrian, less equipped versions of smaller displacement.

2) The reality is that the C series had a 90* V angle, which while it made more room for intake plumbing, was inferior from an NVH and packaging standpoint. Pretty much every 90* V6 design was replaced by a 60* unit because of the inherent vibration benefits. A 90* V6 can be done, but it needs balance shafts to run like a 60* V6, which adds friction, cost, complexity, and weight.

3) The J series has several architectural advantages over the C32 such as low friction roller rocker valvetrain, VTEC (which no SOHC C series offered), smaller dimensions, and lighter weight. It was also more expandable in terms of dimensions IIRC.

4) You seem to misunderstand the advantages of DOHC vs SOHC.

Honda didn't choose SOHC simply because it was "cheaper." They chose it for very several specific reasons.

First, it is more compact than a DOHC layout. This results in a tangible savings in head size, since they don't need as much material to house the camshafts. Less material = less weight AND smaller size. Since the heads sit at the top of the block, this has a direct benefit to mass distribution of the powertrain. Don't forget that the average camshaft weighs somewhere on the order of 15-20lbs and the engine has lost nearly 30-40lbs just by leaving the extra cams out. That is mitigated somewhat by the extra rocker assembly mechanism, but in the end, the extra rocker arms are lighter than the extra cam. They also have less mechanical friction, and less rotating inertia.

The SOHC packaging also more readily allows ideal valve angles, especially when compared to the first gen DOHC VTEC engines, which had very large, wide heads, with less than ideal valve angles. The F20C and K series largely rectified these issues, although they are probably still larger overall than a SOHC setup.

Also, there is no inherent advantage of DOHC vs SOHC. Once companies started to figure out efficient ways to get a SOHC to open 4 valves per cylinder, many of the advantages of DOHC were mitigated.

The only major advantage in this day and age is the ability to add VTC independently to the cams. With a SOHC design, you either have to move the whole cam at the same time (limited benefits), or you have to have a multi piece cam, both of which have already been done.

Also, keep in mind that Honda has already implemented VTEC on BOTH intake and exhaust valves with the latest versions of the J37, so other than cam phasing, and other architectural specifics that don't necessarily relate to a SOHC design, the J series is really only lacking cam phasing. Considering the output and torque curve though, it may help some, but not as much as some would think.

You can argue about VCM all you want, and I won't spend much time disagreeing. However, in non-VCM form, the J series really doesn't give up much of anything to the competition, especially considering its age and simplicity. I am sure the next V6, which should be debuting shortly, will probably advance the technology front quite a bit.

LMAO

no need to try and "school" someone...on engines

It is obvious that you do not believe in DOHC technology and what Honda has achieved with their original V6 series engine.

I'm "simply" saying that Honda should have incorporated DOHC heads with the design of its next gen V6 (j-series) if everything else was improved on compared to the C- Series, why not add DOHC tech

So what if SOHC is more compact than DOHC... Toyota and Nissan have installed DOHC V6s in their midsize cars since 1990.

Nevermind its power, materials, smoothness, friction, exotic materials, weight distribution, or 90*60*75* degree agles - that you are pushing -- the point is that DOHC V6 engines can and will fit within FWD car designs, and Honda's competitors have been installing them into lesser midsize cars for over 2 decades

funny that you bring up the Kseries- The DOHC K-series is "truly" an excellent successor to the wonderful DOHC B-series

imagine if the K- Series was SOHC

"SOHC with it's inherrent(packaging?) advantages over DOHC"

LMAO - imagine the backlash

-bOOgiZ