Fordmods Logo

3.9 head on 4.0 motor 

 

Page 1 of 1 [ 6 posts ] 

 
 Post subject: 3.9 head on 4.0 motor
Posted: Mon Apr 24, 2006 6:15 pm 
Fordmods Newbie
Offline

Posts: 7

Joined: 28th Jun 2005

Ride: EA Falcon

Location: Perth
WA, Australia

Does anyone know the pros and cons about fitting a head (complete) from a 3.9 litre motor onto a 4 litre block
Top
 Profile  
 
 
Posted: Mon Apr 24, 2006 6:18 pm 
Getting Side Ways
Offline
User avatar

Posts: 3115

Joined: 20th Dec 2004

Ride: Falcon

Location: Adelaide
SA, Australia

The head doesnt flow as well as the 4.0's, it will also bump the compression up compared to a 4.0 head on the same bottom end.

 

_________________

Stoke me a clipper, I'll be back for Christmas

Top
 Profile  
 
 
Posted: Mon Apr 24, 2006 6:28 pm 
Fordmods Newbie
Offline

Posts: 7

Joined: 28th Jun 2005

Ride: EA Falcon

Location: Perth
WA, Australia

Thanks for the info, I thought that there would be a reason why there would be a change, I will repair existing head(4 litre) rather than fir the good 3.9 head that I have.
Top
 Profile  
 
 
Posted: Mon Apr 24, 2006 6:31 pm 
Tyre Shredder
Offline

Age: 30

Posts: 376

Joined: 9th Feb 2006

Location: melbourne
VIC, Australia

the 3.9 head will have smaller ports and chambers, thus increasing air velocity (up to 3000rpm) and bump up compression ratio....this will give you good bottom end torque!

wouldnt you prefer that?

 

_________________

Image

Top
 Profile  
 
 
Posted: Mon Apr 24, 2006 6:38 pm 
Getting Side Ways
Offline
User avatar

Posts: 3115

Joined: 20th Dec 2004

Ride: Falcon

Location: Adelaide
SA, Australia

MYLO_XR6 wrote:
the 3.9 head will have smaller ports and chambers, thus increasing air velocity (up to 3000rpm) and bump up compression ratio....this will give you good bottom end torque!

wouldnt you prefer that?


the 3.9 makes peak torque sooner, but also makes less of it.

I doubt any torque increases would be enough to notice, but you certainly will notice the loss above 3000rpm. The 3.9 will work, but if possible its better to fit the head that was designed to go on the engine.

 

_________________

Stoke me a clipper, I'll be back for Christmas

Top
 Profile  
 
 
Posted: Mon Apr 24, 2006 11:59 pm 
Stock as a Rock
Offline

Age: 31

Posts: 153

Joined: 28th Apr 2005

Gallery: 4 images

Ride: EA Falcon Hybrid

Location: geelong
VIC, Australia

so the 4litres are alot better than da 3.9's are they, is it worth changin a 3.9 engine to a 4litre? is there that much difference? what are da diffrence between da two?

 

_________________

<<<DAN's CARS>>>
* 88 EA Falcon X2
* 81 FJ40
* 73 KE26 X2
* 73 KE20 x2
* 69 KE10 X2
and more

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 1  [ 6 posts ] 

Who is online

Users browsing this forum: Google [Bot] and 40 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

 

 

It is currently Sat Dec 16, 2017 10:49 am All times are UTC + 11 hours

 

 

(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names