SOHC is better then DOHC

[softmuffin]

Hi there,
Myself going to change my satria 1.6 (4G92 SOHC) to DOHC(not engine tukar ya) this weekend but the guy told me after to DOHC, my car pick up is not as good as it is now (SOHC). izzit true.
Pls give me some info here cos the cost of the SOHC to DOHC is around Rm900..
thanks..

 

[acbc]

SOHC has better low end than DOHC which has better mid to high end... also, SOHC is lighter.

 

[mengz]

DOHC has better throttle response compared to SOHC...and like wat acbc said...DOHC has better mid to high end power.....but dun expect lotsa hp increase by converting from SOHC to DOHC. let us know how did the mod go ya....cheers!

 

[chiku]

wat the different max rev SOHC compare to DOHC... if SOHC convert to DOHC... izzit max rev will increase or not.... :unsure:

 

[alien]

Originally posted by acbc@Feb 21 2005, 10:18
SOHC has better low end than DOHC which has better mid to high end... also, SOHC is lighter.

really?.. :huh:
it applies to all cars..?

 

[acbc]

Originally posted by alien@Feb 21 2005, 12:42
really?.. :huh:
it applies to all cars..?

Applies to any car...

SOHC has some advantages over DOHC especially same displacement.

 

[chiku]

Originally posted by acbc+Feb 21 2005, 12:46 --></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (acbc @ Feb 21 2005, 12:46 )</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-alien@Feb 21 2005, 12:42
really?.. :huh:
it applies to all cars..?

Applies to any car...

SOHC has some advantages over DOHC especially same displacement. [/b][/quote]
:unsure: can anyone tell me the different...

 

[taqu]

The more complete question is "4G92 12-valve SOHC convert to 4G92 16-valve DOHC, pros/cons?" :) Coz there're 4-cylinder engines having 16 valves but only use SOHC eg Waja engines or some Honda engines.

About pros & cons of 12-valves (3 valve per cylinder) vs 16-valves (4 valve per cylinder), I copy-paste this statement from Autozine :

A typical 2-valve engine has just 1/3 combustion chamber head area covered by the valves, but a 4-valve head increases that to more than 50%, hence smoother and quicker breathing. 4-valve design also benefit a clean and effective combustion, because the spark plug can be placed in the middle.

4 valves are better to be driven by twin-cam, one for intake valves and one for exhaust valves. Honda and Mitsubishi models prefer to use sohc, driving the valves via rocker arms like the aforementioned Triumph. This could be a bit cheaper, but introduce more friction and hurt high speed power. Therefore the sportiest Honda and Mitsubishi still use dohc.

Hmm it is correct to say that generally DOHC engines have abit weaker low-end compare to SOHC (coz DOHC results in larger intake area resulting in slower air flow) , but most DOHC engines have smaller-diameter & curved intake manifold to improve those low-end torque (I think this also applies to 4G92), so u won't notice that low-end loss, on the other hand this may effect hi-end power, but since DOHC have more potential for hi-revving than SOHC, this is OK.

So, gor for it dude :)

 

[tajulsans]

answering on my friends experience, not my personal experiance..

he converted his wira a/b 1.6 from sohc to dohc.. according to him his top speed has reduced abit but pick up really improve..

dont flame me kay.. :)

 

[acbc]

Australia's most powerful SOHC RB30...

http://www.stalkerz.com/RB30.gif

Or download the PDF: http://www.stalkerz.com/RB30.pdf

 

[TiBuN]

I think the new question is : Is it worthwhile to spend the money for a SOHC -> DOHC conversion???

My personal 2 cents, no. Unless you're planning to keep the car for like.... the next 5 years perhaps?

 

[trex92]

Originally posted by softmuffin@Feb 21 2005, 10:08
Hi there,
Myself going to change my satria 1.6 (4G92 SOHC) to DOHC(not engine tukar ya) this weekend but the guy told me after to DOHC, my car pick up is not as good as it is now (SOHC). izzit true.
Pls give me some info here cos the cost of the SOHC to DOHC is around Rm900..
thanks..

Definitely not true. With a DOHC engine, you can afford to rev your RPM higher which would improve your acceleration. SOHC does not perform as efficiently as DOHC at high RPM.

 

[Revo]

Yep. DOHC is good in HIGH rpm....

 

[tajulsans]

i think the better choice is upgrading the head to Mivec.. cost should be about 1.3k - 1.5k.. can rev much higher than normal dohc..

 

[TypicalGuy]

wonder why mercedes still using SOHC 3 valve tech