Survey by Qualaroo
+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 20 of 21
Like Tree7Likes

Thread: DOHC Vs SOHC i.e Altis engine Vs Civic engine

  1. #1
    ok
    ok is offline
    PakWheeler Follow
    ok's Avatar
    Join Date
    Aug 2005
    Location
    Islamabad
    Age
    39
    Posts
    67
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default DOHC Vs SOHC i.e Altis engine Vs Civic engine

    Guys,
    I was reading the following article on the net on DOHC Vs SOHC.

    "Advantages to having a DOHC engine over a SOHC is that the engine has twice as many intake and exhaust valves as a SOHC motor. This makes the engine run cooler and more smoothly, quietly, and efficiently."


    Has any one really noted the difference ?? of Altis engine run cooler and more smoothly, quietly, and efficiently because of DOHC ??


  2. #2
    Senior PakWheeler Follow
    sali2002's Avatar
    Join Date
    Feb 2005
    Location
    Karachi
    Age
    30
    Posts
    1,077
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    hello!
    SOHC Vs DOHC...
    just wanna add that SOHC on 16 valve is difficult to manage but u get low end performance as compared to same DOHC engine...reason is due to on camshaft is doing that all....but SOHC can't give that High end performance as compared to DOHC...
    DOHC was designed to make engine run smoother and cooler...but DOHC engines are bit heavier than SOHC resulting in highly weighted engines....so i think DOHC can run better than SOHC and can be modified better than SOHC....
    Thanxx

  3. #3
    PakWheeler Follow
    evo8's Avatar
    Join Date
    Feb 2005
    Location
    Karachi
    Age
    35
    Posts
    93
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    i dont understand 1 thing correct me if in topic u said DOHC VS SOHC i.e Altis engine vs civic engine man civic have a V-TEC engine to yah SOHC kahan say agaya ??suzuki is the one who have SOHC enginez n civic have vtecz and toyota have DOHC am i write?? and i head the new corolla 1.8 got DOHC+VTEC technology plz explain as i m not sure abt it.
    The Diffrence b/w the ordinary & extraordinary is just tht little EXTRA

  4. #4
    Senior PakWheeler Follow
    bilalahm's Avatar
    Join Date
    Jan 2004
    Location
    Islamabad
    Posts
    3,045
    Follows
    2
    Following
    0
    Mentioned
    23 Post(s)
    Tagged
    7 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Civic has a VTec SOHC engine yar
    Apart from pakwheels, my blogs can be also be viewed at http://tajziat.blogspot.com/

  5. #5
    PakWheeler Follow
    tech_wiz's Avatar
    Join Date
    Feb 2004
    Location
    Lahore
    Age
    28
    Posts
    814
    Follows
    1
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    @ok, what you read is wrong.

    DOHC doesn't mean twice the vavles compared to SOHC. Take VTi, it is SOHC and 16V while SE Saloon is DOHC and 16V too. Moreover both are 1.6!

    DOHC "only" helps the engine to run efficiently as the intake and exhaust valves work on separate camshafts, where as in SOHC both the intake and exhaust valves work on the same camshaft! In some cases the DOHC engines make more noise as there is an addition of mechanical part in the engine (i.e. extra camshaft)

  6. #6
    PakWheeler Follow
    mazher's Avatar
    Join Date
    Jul 2005
    Location
    Karachi
    Age
    43
    Posts
    454
    Follows
    0
    Following
    0
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    wana add one point from experience.

    have driven both vti and Altis. the current vti/exi appear to be noisier than SE Saloon or Altis.

    engine noise in even a new civic can be heard in the cabin during hard acceleration. not sure what explains that phenomena? can anyone comment on that?

  7. #7
    Senior PakWheeler Follow
    mwm749's Avatar
    Join Date
    Mar 2008
    Location
    Dubai
    Age
    59
    Posts
    1,160
    Follows
    1
    Following
    0
    Mentioned
    29 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    I read this article on Paultan.org which is quite informative, so is being shared



    Plenty of people have been talking about how the Savvy only has an SOHC engine so it is inferior, and old technology. So I decided to post this entry so that people will be better informed on what SOHC or DOHC really is.

    SOHC and DOHC are basically two different ways to configure the valvetrain. In the whole valve train setup there are camshafts, lifters, rockers, valves and springs. It is best that the valvetrain is light. Valves open at intervals of 25 times a second at 3000rpm. If the valvetrain is heavy, when the camshaft lifts it the valvetrain will just keep going up until the valve spring catches it. This is called valve float. You can overcome this with stronger (which means heavier) springs, but this extra weight increases the power requirements to open the valve.
    The cams are driven by the crankshaft, using either a belt or chain called a timing belt or timing chain. If the timing belt/chain snaps and the camshaft stops spinning, the piston coming back up the combustion chamber might hit the open valves. This is very costly. That’s why you should always change your timing belt/chain at the interval specified by your car manufacturer.
    SOHC refers to Single Overhead Camshaft. In the days before DOHC, it was known as OHC, with no need to differentiate between a single or double camshaft. In SOHC, the camshaft is situated in the cylinder head, above the valves. The valves are opened and closed either directly with a shim between the cam lobe and the valve stem, or via a rocker arm. SOHC engine valve configurations typically have 2 or 3 valves per cylinder. It is also possible to have 4 valves per cylinder using SOHC but this translates into a complicated combination of rocker arms and cam lobe shapes. An example would be the 4G92P in my car which is a SOHC but has 4 valves per cylinder.
    DOHC refers to Double Overhead Camshaft. This arrangement uses two camshafts in each cylinder head. Two cams per cylinder head means that a DOHC V engine has 4 camshafts because it has 2 banks of cylinder heads. This allows the manufacturer to easily implement a 4 valve per cylinder setup. Most of the time it also allows the engine to rev higher. It also allows better placement of the valves in an optimized setup that gives you maximum performance. But the disadvantage of such a setup is more weight, more cost and more complexity. It takes more stuff to drive two camshafts. The main reason to use DOHC is to drive more valves per cylinder. If a SOHC setup can allow 4 valves per cylinder, having a DOHC engine will not bring that much benefits over SOHC and the additional weight becomes a burden instead. DOHC engines also allows the spark plug to be placed right in the middle of the combustion chamber. This promotes efficient combustion. With SOHC, the camshaft is usually in the middle of the head because it has to drive both the intake and exhaust valves, robbing the sparkplug of it’s optimal location.
    In the end, a SOHC 16 valve engine would have better torque on the low end where the DOHC valvetrain’s weight results in lower torque. But at high engine speeds, the 16 valve DOHC engine’s peak torque and horsepower would be greater. That’s the trade-off. With the amount of valves being equal, SOHC has better low-end torque because the valvetrain package is lighter while DOHC has better top-end power.
    Other benefits of DOHC would be making it easier to implement variable valve timing technologies (which I will cover in another blog post) and also you can tweak it better with adjustable cam pulleys. If you were to put high-profile cams in your DOHC engine, the cam lobe profile can also be more optimized than a SOHC engine because you can play around with the lobe shape easier with separate camshafts for the intake and exhaust valves.
    Why more valves per cylinder? Why not just make 1 huge intake valve and 1 huge exhaust valve? Bigger valves weigh more than the smaller one, so controlling the extra weight as it gets flung open and close becomes difficult. The spring has to be stiffer. A stiffer spring means more energy has to be spent overcoming the valve pressure. This partially oversets the gains which a bigger valve has to offer. Another problem with a single big valve is at lower RPMs the intake velocity will be lower. I’m sure you guys know this… the same amount of air going through a big pipe will have lower pressure than the same air going through a smaller opening. Think of how you can control the water pressure of your garden hose by adjusting the opening size with your finger. Because of the velocity drop, low RPM torque and driveability will suffer. Although two smaller valves weigh the same as 1 big valve, and with the extra rocker arms and springs they can actually end up weighing more, this is offset by less mass to be overcome when opening and closing the valves.
    So, are more valves per cylinder really that beneficial? Here’s comparing a Nissan VG30E to a VG30DE. Both are 3 liter electronic fuel injection engines, but one is a SOHC with 2 valves per cylinder and the other is DOHC with 4 valves per cylinder.
    DOHC Vs SOHC   i.e Altis engine Vs Civic engine - thumb sohcvsdohchp DOHC Vs SOHC   i.e Altis engine Vs Civic engine - thumb sohcvsdohctq
    We can see that torque at low RPMs are about the same for both engines, but at higher speeds the 2-valve per cylinder engine has reached it’s peak and has to switch to the next gear while the twincam 4 valve per cylinder engine continues making more power at the top-end of the powerband. The powerband is also longer. (Note: I’ve added this graph here to show you the difference between 2-valve and 4-valves, not SOHC vs DOHC. Couldn’t find any graphs for SOHC vs DOHC. Sorry!)
    So to sum it all up, SOHC has better low-end power, DOHC has better high-end power and overall maximum power. 4 valves per cylinder is much better than 2 valves per cylinder and it doesn’t matter whether 4-valves is achieved via SOHC or DOHC.
    I Dont Drive Fast, I Fly Slowly....

  8. #8
    Senior PakWheeler Follow
    levin's Avatar
    Join Date
    Oct 2005
    Location
    Select City
    Age
    51
    Posts
    23,112
    Follows
    5
    Following
    0
    Mentioned
    95 Post(s)
    Tagged
    6 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    what engine altis has?

    did you actually see timing belt going over two pullies outside the engine?

    can anyone post pic without cam cover?

    sohc engine actually has more low end torque. i found this out a decade before this thread.

    do you drive at 5000 rpm or above normally or do you drive at 2500rpm normally?
    ,,, unless you know the track, you're not good enough to sit behind the wheel." K T

  9. #9
    PakWheeler Follow
    fairleo's Avatar
    Join Date
    Sep 2006
    Location
    Pak pattan sharif
    Age
    33
    Posts
    279
    Follows
    1
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by levin View Post
    what engine altis has?

    did you actually see timing belt going over two pullies outside the engine?

    can anyone post pic without cam cover?

    sohc engine actually has more low end torque. i found this out a decade before this thread.

    do you drive at 5000 rpm or above normally or do you drive at 2500rpm normally?
    altis had a 1ZZ-FE DOHC 1.8l
    altis has timing chain not timing belts and it can only be seen by opening tappet cover.

  10. #10
    Senior PakWheeler Follow
    levin's Avatar
    Join Date
    Oct 2005
    Location
    Select City
    Age
    51
    Posts
    23,112
    Follows
    5
    Following
    0
    Mentioned
    95 Post(s)
    Tagged
    6 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by fairleo View Post
    altis had a 1ZZ-FE DOHC 1.8l
    altis has timing chain not timing belts and it can only be seen by opening tappet cover.
    oh i didnt know that.

    i used to have 2azfe, and it was not quiet , it used to scream at higher rpm, so i assume 1zzfe is also very noisy engine.
    ,,, unless you know the track, you're not good enough to sit behind the wheel." K T

  11. #11
    Senior PakWheeler Follow
    huzaifaa's Avatar
    Join Date
    Apr 2009
    Location
    Select City
    Age
    27
    Posts
    10,156
    Follows
    3
    Following
    0
    Mentioned
    131 Post(s)
    Tagged
    18 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by evo8 View Post
    i dont understand 1 thing correct me if in topic u said DOHC VS SOHC i.e Altis engine vs civic engine man civic have a V-TEC engine to yah SOHC kahan say agaya ??suzuki is the one who have SOHC enginez n civic have vtecz and toyota have DOHC am i write?? and i head the new corolla 1.8 got DOHC+VTEC technology plz explain as i m not sure abt it.
    r u kidding or what?
    suzuki liana is SOHC??????? no

  12. #12
    Senior PakWheeler Follow
    huzaifaa's Avatar
    Join Date
    Apr 2009
    Location
    Select City
    Age
    27
    Posts
    10,156
    Follows
    3
    Following
    0
    Mentioned
    131 Post(s)
    Tagged
    18 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by mazher View Post
    wana add one point from experience.

    have driven both vti and Altis. the current vti/exi appear to be noisier than SE Saloon or Altis.

    engine noise in even a new civic can be heard in the cabin during hard acceleration. not sure what explains that phenomena? can anyone comment on that?
    yar whats there in idsi its super silent then n e other car

  13. #13
    Senior PakWheeler Follow
    immad100's Avatar
    Join Date
    Aug 2010
    Location
    Lahore
    Posts
    5,503
    Follows
    1
    Following
    0
    Mentioned
    26 Post(s)
    Tagged
    8 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by evo8 View Post
    i dont understand 1 thing correct me if in topic u said DOHC VS SOHC i.e Altis engine vs civic engine man civic have a V-TEC engine to yah SOHC kahan say agaya ??suzuki is the one who have SOHC enginez n civic have vtecz and toyota have DOHC am i write?? and i head the new corolla 1.8 got DOHC+VTEC technology plz explain as i m not sure abt it.

    whufffff...
    @evo8 bro please gather some ri8 knwldge.rolla with vtec???????u r kiddin for sure.
    ''Peace is an unstable equilibrium,that can only be preserved by acknowledged supremacy and...equal power.'' ''We give up the fort when there is not a man left to defend it.''

  14. #14
    Senior PakWheeler Follow
    immad100's Avatar
    Join Date
    Aug 2010
    Location
    Lahore
    Posts
    5,503
    Follows
    1
    Following
    0
    Mentioned
    26 Post(s)
    Tagged
    8 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by mazher View Post
    wana add one point from experience.

    have driven both vti and Altis. the current vti/exi appear to be noisier than SE Saloon or Altis.

    engine noise in even a new civic can be heard in the cabin during hard acceleration. not sure what explains that phenomena? can anyone comment on that?
    well regardin 8th gen's cabin noise i dont agree at all.
    ''Peace is an unstable equilibrium,that can only be preserved by acknowledged supremacy and...equal power.'' ''We give up the fort when there is not a man left to defend it.''

  15. #15
    Senior PakWheeler Follow
    ahsanonline's Avatar
    Join Date
    Jan 2007
    Location
    Rawalpindi
    Age
    86
    Posts
    2,295
    Follows
    3
    Following
    3
    Mentioned
    19 Post(s)
    Tagged
    3 Thread(s)
    Problems Posted
    2
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    wow. a 6 year old thread resurrected.

    dohc vs. sohc have to be taken separate from 2 valves vs. 4 valves.

    dohc implies two camshafts, one for exhaust and one for intake. thus widely different cam profiles for both intake and exhaust can exist in a dohc engine. but coz of extra moving parts its usually more noisy.

    sohc implies all valves running off the same camshaft. any changes in cam profile affect both intake and exhaust valves simultaneously. less tunability. usually less noise because of lesser moving parts.

    the altis 1.8 and now the 1.6 altis both have dohc engines.

    the current 'reborn' civic and the current city both have sohc engines.
    Selling Vitz+local cars - compatible bluetooth Ecu Scantool, High-amp car chargers, Apple-certified Lightning Cables, etc. Click on my name and see my started threads for details.

  16. #16
    Senior PakWheeler Follow
    SpoonMotorSports's Avatar
    Join Date
    May 2010
    Location
    Peshawar
    Posts
    1,493
    Follows
    1
    Following
    0
    Mentioned
    15 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default don't under estimate sohc

    Save the SOHC
    Hide the Dohc! \../
    Honda Tuning Solutions
    03468152233

  17. #17
    Site Banned Follow
    BlueHorn's Avatar
    Join Date
    Apr 2011
    Location
    Lahore
    Posts
    1,717
    Follows
    0
    Following
    0
    Mentioned
    99 Post(s)
    Tagged
    5 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Where is son of civic AEROMERIX ?!!!
    If honda has SOHC then that is the best technology in the whole world. Period ... am i right Aeromerix bin Civic .... actually it is Aeromerix BINT Civic !!!

  18. #18
    Senior PakWheeler Follow
    accord7362's Avatar
    Join Date
    Jun 2008
    Age
    44
    Posts
    8,290
    Follows
    2
    Following
    6
    Mentioned
    197 Post(s)
    Tagged
    34 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Dont kn much about DOHC or SOHC , but I did give a SHOCK to 1.8Altis(auto) 2008-09(old shape) with my L15A, Vtec steermatic

    https://www.pakwheels.com/forums/mem...-accord7362-24

    Page 24 , post 478
    http://www.pakwheels.com/forums/members-member-rides/266031-accord7362s-merc-thanks-god-loved-ones-who-remember-me-prayers ,199119-thanks-god-2011-ford-edge-limited-awd-3-5-v6

  19. #19
    Senior PakWheeler Follow
    wasay_ahmed's Avatar
    Join Date
    Nov 2006
    Location
    Lahore
    Age
    29
    Posts
    4,959
    Follows
    3
    Following
    0
    Mentioned
    12 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    if you talk abt locally assembled DOHC based engine cars Altis,swift,gli etc all are perfect examples of Non fuel effiecent n underpowered on the same time.Yet if we see SOHCs lets talk abt City,Lancer,Civic,Cultus etc they are fuel effiecent if arnt atleast they are powerfull.
    DIY The Best Workshop on the Holy Planet!
    Every thing changes,Its only the "change" which never changes.

  20. #20
    PakWheeler Follow
    Devastator's Avatar
    Join Date
    May 2009
    Location
    Riyadh
    Posts
    421
    Follows
    0
    Following
    0
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by evo8 View Post
    i dont understand 1 thing correct me if in topic u said DOHC VS SOHC i.e Altis engine vs civic engine man civic have a V-TEC engine to yah SOHC kahan say agaya ??suzuki is the one who have SOHC enginez n civic have vtecz and toyota have DOHC am i write?? and i head the new corolla 1.8 got DOHC+VTEC technology plz explain as i m not sure abt it.
    i know this is a dig but still gotta troll over this one!
    this guy needs to get his facts clear, suzuki swift, jimny, liana all got the m13 engine i.e. dohc, vtec is a technology created by honda which alters the valve lifting timings as for economy to sports conversion mode for a layman, toyotas have the vvti technology, the civics we get in pk are all sohcs but hell the Honda B series is a killer dohc, but y m i telling you this!

    to me
    DOHC = sheer power
    SOHC = economy (i would swap em any day if i want to squeeze em horses from my motor)

    Quote Originally Posted by SpoonMotorSports View Post
    Save the SOHC
    Hide the Dohc! \../
    more like safe the sohc, drive the dohc!

+ Reply to Thread
Page 1 of 2 12 LastLast

User Tag List

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •