Notices
Honda Prelude All Model Preludes

How does the Vtec work?

Old 01-17-2011, 12:49 AM
  #1  
Honda-Tech Member
Thread Starter
 
rumo1112's Avatar
 
Join Date: Mar 2010
Location: OC
Posts: 32
Likes: 0
Received 0 Likes on 0 Posts
Icon3 How does the Vtec work?

When the H22 Vtec solenoid activates the hydrolic control valve which moves the synchronizing piston to lock all 3 rocker arms. Does it lock the header rocker arms too? or just the Intake rocker arms?

I've seen all those how vtec work videos but they are %100 full descriptive, they just give the basics of how vtec works. None of them say how the oil flows through the Vtec solenoid or whether the rocker arms lock on both sides of the camshafts. Not good enough, lol
Old 01-17-2011, 05:23 AM
  #2  
Honda-Tech Member
 
Acidcrakker's Avatar
 
Join Date: Aug 2007
Posts: 3,895
Likes: 0
Received 0 Likes on 0 Posts
Default Re: How does the Vtec work?

Vtec works off oil pressure and the solenoid.

The higher the engine RPM the higher the oil pressure.

Vtec requires something like 50psi of oil pressure to work. So at 5200 rpms there is enough pressure.

The ecu sends a signal to the the vtec solenoid. The solenoid is activated and allows the oil pressure to flow into the rockers extra lobe. This extra lobe lifts up and is now part of the other 2 lobes, creating one big lobe that allows for more air to enter the combustion chamber.

Short story something like this
Old 01-17-2011, 05:54 AM
  #3  
Honda-Tech Member
 
ilikehonda's Avatar
 
Join Date: Jul 2005
Location: Springfield, mo, usa
Posts: 1,556
Likes: 0
Received 3 Likes on 3 Posts
Default Re: How does the Vtec work?

Originally Posted by Acidcrakker
Vtec works off oil pressure and the solenoid.

The higher the engine RPM the higher the oil pressure.

Vtec requires something like 50psi of oil pressure to work. So at 5200 rpms there is enough pressure.

The ecu sends a signal to the the vtec solenoid. The solenoid is activated and allows the oil pressure to flow into the rockers extra lobe. This extra lobe lifts up and is now part of the other 2 lobes, creating one big lobe that allows for more air to enter the combustion chamber.

Short story something like this
False.

MAGIC is how it works.

You are correct about the oil pressure but the pressure pushes a locking pin from the outside rockers in to the middle rocker. It locks all three rockers together and you are able to run off the vtec lobe.
Old 01-17-2011, 07:02 AM
  #4  
Cool Cool Island Breezes. BOY-EE
iTrader: (1)
 
B serious's Avatar
 
Join Date: Sep 2006
Location: TRILLINOIS....WAY downtown, jerky.
Posts: 11,953
Likes: 0
Received 4 Likes on 4 Posts
Default Re: How does the Vtec work?

He was asking a much simpler question.

Op:
SOHC VTEC activates only the intake side.
DOHC VTEC activates both sides. So the h22 activates both sides.
Old 01-17-2011, 10:25 AM
  #5  
Honda-Tech Member
 
autoluder's Avatar
 
Join Date: Sep 2007
Location: Evansville, IN, USA
Posts: 429
Likes: 0
Received 0 Likes on 0 Posts
Default Re: How does the Vtec work?

there are good youtube videos on this...
Old 01-17-2011, 10:57 AM
  #6  
Honda-Tech Member
 
nus_dogg's Avatar
 
Join Date: Oct 2008
Location: St. Paul, MN
Posts: 3,728
Received 7 Likes on 6 Posts
Default Re: How does the Vtec work?

Word.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
vtecn8ive
Honda CRX / EF Civic (1988 - 1991)
22
08-03-2005 01:06 PM
s1ngle
Honda Civic / Del Sol (1992 - 2000)
5
05-06-2005 06:50 PM
tunes12
Tech / Misc
16
10-04-2002 08:11 PM
r7
Honda CRX / EF Civic (1988 - 1991)
8
06-28-2002 02:24 PM


Thread Tools
Search this Thread
Quick Reply: How does the Vtec work?



All times are GMT -8. The time now is 08:39 PM.