Donte99TL

This is going to sound like a dump question but in my owners manual it said that the TL's are SOHC. Is this true?

Nate

Yeah, those manuals were in fact made for your car you know. SOHC is actually better than DOHC I believe.

AC

Damn sure ain't DOHC cuz that would be an NSX engine.

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2000 TL Taffeta White
Factory Body Kit and Spoiler
18' DAZZ MATIZ
Tenzo 700X Fogs
Custom Mesh Grille
Custom Mesh Bumper Center
Comptech Headers
Comptech Springs
Comptech Sway Bars
AEM CAI
Greddy CatBack Exhaust
Inspire Tails
Inspire Steering Wheel
Burlwood Knob
Apexi V-AFC

socal28

SOHC's will give better low end torque than DOHC's. That's why tegs and S2000's don't have low-end torques.
Just my 2 cents.

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1999 Dark Emerald Pearl TL w/ nav
Factory underbody kit and rear spoiler.
Comptech springs, sways, headers and exhaust.
RS Akimoto Funnel Ram III Intake.
18x7.5 +48 5Zigen Heidfeld wheels with 225/40ZR18 Nitto NT-555 tires.
Inspire Tail-lights with Polarg M-23 P8711R signal bulbs.
DEI Viper 550ESP Alarm
http://home.socal.rr.com/tada/socal28TL.htm

hunter001

It is all in the way manufacturers prefer to implement their engines.

All Mercedes Benz engines are SOHC (3 valves per cylinder) regardless of whether it is the Mercedes C-class with 3.2L and 2.6L engines, the Mercedes E-class with 3.2L and the various V8 engines, the Mercedes S-class with the various V8 engines and the V12, the Mercedes SLK, the Mercedes M-class etc.... while the Acura 3.2TL/CL-s engines are SOHC (4 Valves per cylinder).

This Acura engine in the 3.2TL (paired with the auto transmission) can thrash the 3.0L DOHC engine (4-valves per cylinder) present in the lighter Infiniti I-30 (with auto transmission) that theoretically puts out more power, all the way from 0-30, 0-40, 0-50, 0-60, 0-70, 0-80, 0-90 and the quarter mile. The same humiliating fate is dealt out to the Lexus 3.0L DOHC engine (4-valves per cylinder). In both of these cases, the Acura nets better mileage too, while slapping its competitors around in acceleration. Incidentally, both these cars (the Infiniti and the Lexus) are lighter than the Acura 3.2TL.

The Honda civic employs a 1.6L SOHC engine (in various configurations) while the Acura Integra uses a 1.8L DOHC engine (in various configurations). The Accord 4 cylinder is an SOHC 4 cylinder (4 valves per cylinder) while the Honda Prelude is a DOHC 4-cylinder (with 4-valves per cylinder).

The NSX employs a 3.2L DOHC engine (4-valves per cylinder).

All BMWs have a DOHC configuration (with 4-valves per cylinder) while all Audis have the DOHC configuration (with 5-valves per cylinder).

The new 4.0L V8 RL/Legend/NSX engine in development is believed to have a DOHC 5-valves per cylinder configuration.

Ultimately, it all depends on the way the car companies decide to implement their engine configurations and also the specific application (whether it is a car, SUV etc.) and the way they decide to tune it.




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2000 Naples Gold 3.2TL/Navi - Factory Stock but with up-graded tires

Atomix

Hmmm....no one has really answered the question, so i'll fill in for Einstein...

Ok, SOHC is cheaper, but in traditional form can only actuate 2 valves per cylinder. 2V engines have better low end torque because the low speed air has less space to move into the cylinder, thus moves faster, thus burns more efficiently....actually read this page...... http://www.fortunecity.com/silversto...tm#Multi-valve

The reason Acura used SOHC with rocker arms is essentially cost savings. SOHC is cheaper, and easier to make (especially for American's building Jap cars). DOHC is more sophistocated, more advanced, more expensive, but is more efficient and has a better top end. DOHC does not have to have poor low end torque. If the I30 had a 5-speed auto, or you just bought a 5-speed manaul Maxima, especially the latter, it is faster than a TL.

Also, as Einstein once told me, if the TL engine were DOHC, one of those cams would have to be punching up through the hood....

Therefore, SOHC is a little more compact, and a lot cheaper. And in earlier applications, without rocker arms, and thus only running 2 valves per cylinder, makes more power.

Another little size note, the DOHC I30 engine (the VQ30DE) has won the 10 best engine award for every year it has existed, whereas the TL's engine has quietly done it's job, using VTEC to make up for it's deficiencies

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"Now you see that evil will always triumph, because good is dumb." --Dark Helmet

www.distributed.net

Atomix

Ok, i agree with you on most points...

Honda does make a very good DOHC engine, but it seems to have difficulty doing so in mass quantities. While we all agree that the NSX, S2000 and type R have awesome DOHC's, they are hand built and in limited quantities, though still respectable.

Honda seems to be moving further towards SOHC now, with the new Civic being exclusively SOHC. However, the previous civic engines that were DOHC were quite excellent in their own right, but nothing like the S2000 engine as far as engineering achievements go.

It seems honda has placed it's faith in VTEC rather than DOHC, but the cost savings gained by using SOHC VTEC engines is nerely negated by the cost of implimenting VTEC.

All we can do is hope that honda will create a DOHC VTEC V6 for a mid-size sedan, then Honda will truely have a class leading engine and a very potent sedan.

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"Now you see that evil will always triumph, because good is dumb." --Dark Helmet

www.distributed.net

pimplaas

this is how it goes sohc engines are made to rev high and that's why honda put's vtec in them so they can get more power out of them than dohc engines however dohc is better for engines that don't have vtec

<FONT COLOR="#800080" SIZE="1" FACE="Verdana, Arial">[This message has been edited by pimplaas on January 20, 2001 @ ]</font>

Atomix

Hrmmm......one little thing.....S2000.

"thank you sir, may i have another?"

j/k, SOHC's do rev faster, because they have less reciprocating mass, thus less inertia to overcome to reach high revs quickly. However, in road going cars, this is less of an issue, especially in an automatic. What is really holding back the revs is the resistance provided by why the engine is connected to, the transmission, which is connected to the half-shafts, which go to the wheels, which connect the tires......to the road.

SOHC is actually not very good for top end power, where the cheap solution of rocker arms really begins to take it's toll. This is similar to the rather dramatic loss the pushrod engines suffer when their revs build to a frenzied pace. The Z06 corvette for example has torque from here to thursday, but it's power drops off fairly quickly as you come within about 1000 rpms of the redline. The mechanical friction provided by rocker arms, or pushrods, grows exponentially as the number of revolutions builds.

The TL's engine uses VTEC to help compensate for a low end that can be weak at times, due to the problems inherant in 4+ valve per cylinder engines. While this helps, the TL can still feel sluggish at lower engine speeds. The way in which the Maxima's VQ deals with this problem is variable length intake runners, this makes a very big difference, and does help a great deal. However, when mated to a 4-speed automatic, the breathing difficulties associated with a 4 valve per cylinder engine, have a longer duration, because of the longer gearing.

Ok, i'm tired now, that's enough learnin' for one night.

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"Now you see that evil will always triumph, because good is dumb." --Dark Helmet

www.distributed.net

hunter001

It is true that the Nissan engine has been winning the Ward's 10 best engines award.....so has the General Motors' ancient 3.8L pushrod V6 (which is booed and jeered everywhere else in the world except the US).....as soon as GM shifted their focus from the 3.8L pushrod V6 and developed a 3.5L DOHC V6 (currently available in the 3.5L Olds Intrigue and the Aurora V6), Wards immediately mentioned that pushrod engines (GMs 3.8V6) are out of the scope of the awards and the new awardee is the 3.5L V6......which leads me to the question, who are these fellows who determine these awards ?!!! Are they impartial automobile engineers...or are they a group who is owned in part by BMW, GM, Nissan and so on ?!!! Is there anything that the 3.5L DOHC V6 engine (210hp, 90 degree V6) of GM does that the 3.2L highly sophisticated Variable valve timing normally aspirated engine of Acura in the CL-s (SOHC, 260HP, 60 degree V6) cannot do ?!!!! Why does Ward's always makes sure that a GM engine (be it 3.8L or 3.5L) belong in the 10 best list ?......I frankly do not lay much credibility by "10 best engine award from Ward's" or whatever....the fellows last year, reluctantly bought the Honda S2000 engine into the "10 best list" because otherwise, people would jeer at those "awards"...just my 2c

Yes, it is also true that a DOHC configuration is more tunable than an SOHC configuration. No question about it. No way would Honda have accomplished the incredible 240 hp from the 2L engine of the S2000 from an SOHC configuration. The other part of the equation is that no manufacturer can play wizardry with engines like Honda (among the mass market manufacturers, BMW is a close second)....and to say otherwise is being "not so wise". Hell, a company which overwhelmingly dominated F1 racing during their years in F1 (neither Toyota nor Nissan stands anywhere near Honda in racing at that level, incidentally).... can do with SOHC engines, that takes many other manufacturers DOHC to accomplish....some additional 2c

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2000 Naples Gold 3.2TL/Navi - Factory Stock but with up-graded tires

hunter001

Actually, all the previous generation civic engines were 1.6L SOHC engines (LX putting out 106hp while the EX having 127Hp) with the Civic Si being the only exception which had a 1.6L DOHC Vtec engine (Putting out 160hp).....the Si was bought almost towards the end of the previous generation civic's life-cycle with its engine having made its presence felt earlier in the Honda del sol which was discontinued earlier.

The newer Civics are all 1.7L SOHC engines....I would expect a DOHC Si version to come within the next 2 years.

The new Acura Integras (or RS ?)would have a 2.0L DOHC engine that would have 200hp (in the lower trim levels) while the GSR 2.0L DOHC engine would have 220hp. Even though the Integras share a lot of components with the Civic, they have different engines/transmissions and are also exclusively built in Japan with 100% Japanese components. Incidentally, the new Acura MDX's Engine (3.5L but very similar to the 3.2L TL engine) and Transmission are built in Japan, while the 3.2L engine of the TL is built in the USA but the TL's 5-speed sportshift transmission is built in Japan.


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2000 Naples Gold 3.2TL/Navi - Factory Stock but with up-graded tires

hunter001

To simplify the previous paragraph:

Honda DOHC engine is better than a Honda SOHC engine of the same displacement.

Honda SOHC engine is better (or at least equal) to DOHC engines of competitors like Nissan or Toyota with comparable displacement.

Honda DOHC engines are in a different realm altogether (overwhelmingly superior) when compared to DOHC engines of an equivalent displacement of its competitors like Nissan/Toyota.


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2000 Naples Gold 3.2TL/Navi - Factory Stock but with up-graded tires

<FONT COLOR="#800080" SIZE="1" FACE="Verdana, Arial">[This message has been edited by hunter001 on January 20, 2001 @ ]</font>