Honda Car Forum


 

Go Back   Honda Car Forum - Accord Parts Civic Tuning Acura Racing > Discussion > Honda Technical

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 12 Oct 2007, 04:33 pm
Junior Member
 
Join Date: Sep 2007
Posts: 12
Default what does DOHC for?

I know what it means, i just want to know what it's for and how it helps the engine work better.
Reply With Quote
  #2 (permalink)  
Old 12 Oct 2007, 04:36 pm
Junior Member
 
Join Date: Oct 2007
Posts: 1
Default

On a dual over head cam the cams are right in the head and have a direct drive to the valves this gives it more dependability and allows the vehicle to perform much better than a conventional camshaft.
Reply With Quote
  #3 (permalink)  
Old 12 Oct 2007, 04:39 pm
Junior Member
 
Join Date: Oct 2007
Posts: 1
Default

Dual Overhead Cams
Reply With Quote
  #4 (permalink)  
Old 12 Oct 2007, 04:42 pm
Junior Member
 
Join Date: Aug 2007
Posts: 9
Default

dual over head cam
Reply With Quote
  #5 (permalink)  
Old 12 Oct 2007, 04:45 pm
Junior Member
 
Join Date: Aug 2007
Posts: 4
Default

Dual overhead cams allows the engine to obtain higher RPMs and thus higher horsepower compared to an overhead valve engine with the same displacement and number of cylinders. Overhead valve (pushrod) engines are limited because the the pushrods will break if revved too high. A dual overhead cam engine allows for more valves as opposed to a single overhead cam engine and thus also produces more power. Having more valves allows an engine to "breath" better. There is usually one cam for intake valves, and the other cam for exhaust valves.
Reply With Quote
  #6 (permalink)  
Old 12 Oct 2007, 04:48 pm
Junior Member
 
Join Date: Oct 2007
Posts: 3
Default

Bad part, screw your cam; screw your block....
Reply With Quote
  #7 (permalink)  
Old 12 Oct 2007, 04:51 pm
Junior Member
 
Join Date: Sep 2007
Posts: 12
Default

Duel Over Head Camshaft,the reason an engine works a lot better is the engineers can design the intake duration and exhaust duration differently on separate cams than if they on one single camshaft,just by off setting the cam drive on each camshaft they can achieve more horse power.If you think this is technical try HCVVT.Hydraulically Controlled Variable Valve Timing.Does the same thing only a lot better and it's computer controlled.
Reply With Quote
  #8 (permalink)  
Old 12 Oct 2007, 04:54 pm
Junior Member
 
Join Date: Aug 2007
Posts: 3
Default

instead of having a single camshaft doing all the opening and closing of the intake and exhaust valves. A Dual Overhead Camshaft is cheaper to tune because in a SOHC, you need to grind a whole new camshaft to change the power/economy/emissions. In a DOHC, all you gotta do is change to timing on the exhaust camshaft if you wanna change power/economy/emissions settings. Also, 2 camshafts are smaller and lighter than 1 big camshaft. so it's lighter because it uses less metal, and it's less work to turn two little camshafts vs. a big heavy camshaft.My Chrysler 300M is a SOHC but it's got 24 valves, so it still breathes but it's got less parts than a DOHC so it's cheaper to make. And nobody is gonna be modifying the breathing on a Chrysler.The other big thing is the sparkplug. it sits in the middle of the DOHC so it fires in the center. The SOHC has to fire the plug from an angle.
Reply With Quote
  #9 (permalink)  
Old 12 Oct 2007, 04:57 pm
Junior Member
 
Join Date: Aug 2007
Posts: 5
Default

it work with both camshaft so the engine fire quicker when you start the car. most honda, toyota, and nissan has it. a very few american, german car have it.
Reply With Quote
  #10 (permalink)  
Old 12 Oct 2007, 05:00 pm
dky dky is offline
Junior Member
 
Join Date: Aug 2007
Posts: 15
Default

D = Dual. meaning it has separate mechanicals controlling intake(1) and exhaust(2) valves, hence, "dual"OH = overhead. meaning the mechanicals controlling the valves are "over" the engine head. they are located closer to the actual parts they're controlling. hence, less distance the force has to travel through the mechanicals.C = Cams. A part that controls the opening and closing of the valvesIn another words, DOHC = "There are two parts that control the valves (cams) located right over the head of my engine."DOHC doesn't always necessarily mean it's better than other designs; i.e. OHV (overhead valve: cam is located farther away from the valves that it controls) or SOHC (single: single cam does both duties, intake and exhaust)and it doesn't always mean it has a "variabale" (another can of worms) technology. it all depends on the application and individual design. But when all else are equal, DOHC design provides more flexible/efficient way for engine to breathe more.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
which is better? DOHC or VTEC? imJUSTcurious Honda Technical 12 23 Jan 2008 09:30 pm
OBD 2 SOHC does it fit OBD 2 DOHC? 011987@sbcglobal.net Honda Technical 2 05 Oct 2007 05:36 pm
What's the different between SOHC and DOHC? yan song h Honda Technical 11 29 Sep 2007 06:40 pm
How hard would it be to drop a 2.2l DOHC V-TEC into a 94 integra w/stock 1.8l DOHC non V-TEC? jcespinoza1978 Acura Technical 3 29 Aug 2007 03:04 pm
1.8l dohc ted5 Acura 2 10 Sep 2006 04:51 pm


All times are GMT -5. The time now is 08:24 am.


Attribution:
Honda News | Autoblog
Powered by Yahoo Answers




Powered by vBulletin®
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc.
HondaCarForum.com is not affiliated with Honda Motor Company in any way. Honda Motor Company does not sponsor, support, or endorse HondaCarForum.com in any way. Copyright/trademark/sales mark infringements are not intended or implied.