General Tech Ask model specific questions in the appropriate category below. All other general questions within.

OHV?

Thread Tools
 
Search this Thread
 
Old Aug 11, 2005 | 01:32 PM
  #1  
NewMexMustang's Avatar
NewMexMustang
Thread Starter
5th Gear Member
 
Joined: Jul 2005
Posts: 2,680
From:
Default OHV?

Ok, I know it stands for overhead valve, but is it still SOHC too? What's the difference w/ OHV's?
Old Aug 11, 2005 | 01:39 PM
  #2  
02StanGT's Avatar
02StanGT
4th Gear Member
 
Joined: Apr 2005
Posts: 1,036
From:
Default RE: OHV?


ORIGINAL: NewMexMustang

Ok, I know it stands for overhead valve, but is it still SOHC too? What's the difference w/ OHV's?
Not always. Single Over Head Cam (SOHC), means cams are over each head. When people say OHV they are usually referring to a pushrod motor (one cam and not over the head).
Old Aug 11, 2005 | 01:40 PM
  #3  
JD1969's Avatar
JD1969
Pro. B.S. caller outer
 
Joined: May 2004
Posts: 9,644
From: IL
Default RE: OHV?

You can have a single over head cam (SOHC) or a dual over head cam (DOHC). OHV refers to the placement of the valve, ie not a flat head type engine. So an OHV motor could be SOHC or DOHC or a pushrod like a 5.0
Old Aug 11, 2005 | 01:53 PM
  #4  
NewMexMustang's Avatar
NewMexMustang
Thread Starter
5th Gear Member
 
Joined: Jul 2005
Posts: 2,680
From:
Default RE: OHV?

So, what is the setup of the 3.9L V6?
Old Aug 11, 2005 | 01:55 PM
  #5  
JD1969's Avatar
JD1969
Pro. B.S. caller outer
 
Joined: May 2004
Posts: 9,644
From: IL
Default RE: OHV?

Thats a push rod setup, single cam in the block.
Old Aug 11, 2005 | 01:56 PM
  #6  
NewMexMustang's Avatar
NewMexMustang
Thread Starter
5th Gear Member
 
Joined: Jul 2005
Posts: 2,680
From:
Default RE: OHV?

Are pushrods good...disadvantages?
Old Aug 11, 2005 | 09:02 PM
  #7  
Guest
Guest
 
Posts: n/a
Default RE: OHV?


ORIGINAL: NewMexMustang

Are pushrods good...disadvantages?
good = creates more torque

bad = not as breathable in the top end of the power band.
Old Aug 11, 2005 | 09:44 PM
  #8  
GreyStang's Avatar
GreyStang
5th Gear Member
 
Joined: Apr 2005
Posts: 3,062
From:
Default RE: OHV?


ORIGINAL: 2000Si


ORIGINAL: NewMexMustang

Are pushrods good...disadvantages?
good = creates more torque

bad = not as breathable in the top end of the power band.
Why would the existence of pushrods create more torque?

Bottom line an cam-in-block or cam-in-head engine is gonna behave pretty much the same way. But the advantage of cam-in-head is there is less complexity, and less pieces. So they can rev much higher without risk of valve float.
Old Aug 11, 2005 | 10:48 PM
  #9  
Magiarn71's Avatar
Magiarn71
3rd Gear Member
 
Joined: Feb 2005
Posts: 646
From:
Default RE: OHV?


ORIGINAL: JD1969

So an OHV motor could be SOHC or DOHC or a pushrod like a 5.0
I have to disagree there. OHV was a way to describe the placement long ago, but they've started refering to an OHV meaning a pushrod engine. I realy think you cant have a OHVDOHC.
Old Aug 11, 2005 | 10:58 PM
  #10  
Guest
Guest
 
Posts: n/a
Default RE: OHV?


ORIGINAL: GreyStang


ORIGINAL: 2000Si


ORIGINAL: NewMexMustang

Are pushrods good...disadvantages?
good = creates more torque

bad = not as breathable in the top end of the power band.
Why would the existence of pushrods create more torque?

Bottom line an cam-in-block or cam-in-head engine is gonna behave pretty much the same way. But the advantage of cam-in-head is there is less complexity, and less pieces. So they can rev much higher without risk of valve float.
It's more in the design of the engine actually. Pushrods are just the usual design in torquey engines.

Low velocity air creates more torque. Pushrods have a horrible top end, usually redling around 5500ish. That puts their torque band from near idle to a few thousand RPMs. Look up the specs on the Viper engines. the SRT10 makes 525 ft lbs somewhere around 1700 rpm.

magiarn: ALL DOHC/SOHC engines are OHV. OHV simply means that the valves are overhead of the engine block. But since SOHC/DOHC are named accordingly, pushrods have been known to be called OHVs since there's only one cam and it sits inside the engine block and not in the head(s) itself/themselves.



All times are GMT -5. The time now is 03:38 PM.