Fordmods Logo

Rod length and compression 

 

Page 1 of 1 [ 10 posts ] 

 
 Post subject: Rod length and compression
Posted: Wed Jun 04, 2008 1:51 pm 
Getting Side Ways
Offline
User avatar

Age: 35

Posts: 1775

Joined: 10th Jul 2007

Gallery: 8 images

Ride: BFII Turbo

Power: 253 rwkw

Location: Waurn Ponds
VIC, Australia

I was wondering in my wondering time this morning, if you could fit AU pistons onto E series con rods? since the e series rods are .2 or so of an inch shorter than AU rods, this would be a pretty easy way of de-compressing a 4 ltr for turbo's or superchargers wouldnt it? it would also rev slightly better due to being squarer, and the FI would make up for the slightly lower torque down low.

how much compression would one loose if the stroke is reduced by that much? would it get it under the 8.5:1 mark?

If it fell too low you could shave off the head a bit to bring it back up...

wonder what the literage would be with the combo. Bet its been done if it can be done. anyone heard anything of it?

 

_________________

enough isn't enough

Top
 Profile  
 
 
Posted: Wed Jun 04, 2008 5:45 pm 
Getting Side Ways
Offline
User avatar

Age: 33

Posts: 1802

Joined: 16th Jan 2005

Gallery: 7 images

Ride: EF Falcon

Location: Horsham
VIC, Australia

dude just save you self the probs
and get a decompresson plate/gasket

 

_________________

EFBIGNIK 145.9 RWKW Falcon / 16.27 @ 86.72mph (Stock)
http://s60.photobucket.com/albums/h38/e ... urnout.flv
Image

Top
 Profile  
 
 
 Post subject: Re: Rod length and compression
Posted: Wed Jun 04, 2008 5:47 pm 
Getting Side Ways
Offline

Age: 33

Posts: 6746

Joined: 13th Mar 2006

Gallery: 10 images

Ride: NCII Fairlane

Location: Bathurst
NSW, Australia

More Grunt wrote:
I was wondering in my wondering time this morning, if you could fit AU pistons onto E series con rods? since the e series rods are .2 or so of an inch shorter than AU rods, this would be a pretty easy way of de-compressing a 4 ltr for turbo's or superchargers wouldnt it? it would also rev slightly better due to being squarer, and the FI would make up for the slightly lower torque down low.

how much compression would one loose if the stroke is reduced by that much? would it get it under the 8.5:1 mark?

If it fell too low you could shave off the head a bit to bring it back up...

wonder what the literage would be with the combo. Bet its been done if it can be done. anyone heard anything of it?


this would be the better way to go to make full turbo only motor.

 

_________________

R.I.P Tobias my son.

Top
 Profile  
 
 
 Post subject: Re: Rod length and compression
Posted: Wed Jun 04, 2008 8:41 pm 
Getting Side Ways
Offline

Posts: 6449

Joined: 11th Nov 2004

More Grunt wrote:
I was wondering in my wondering time this morning, if you could fit AU pistons onto E series con rods? since the e series rods are .2 or so of an inch shorter than AU rods, this would be a pretty easy way of de-compressing a 4 ltr for turbo's or superchargers wouldnt it? it would also rev slightly better due to being squarer, and the FI would make up for the slightly lower torque down low.

how much compression would one loose if the stroke is reduced by that much? would it get it under the 8.5:1 mark?

If it fell too low you could shave off the head a bit to bring it back up...

wonder what the literage would be with the combo. Bet its been done if it can be done. anyone heard anything of it?


you'd lower the comp to far and create more problem then it solves.

the engine will not be any 'squarer'. that is determind by the stroke and bore. not by the installed lenght of the rod and piston

 

_________________

PERMANENTLY BANNED

Top
 Profile  
 
 
 Post subject: Re: Rod length and compression
Posted: Thu Jun 05, 2008 12:10 am 
Getting Side Ways
Offline

Age: 33

Posts: 6746

Joined: 13th Mar 2006

Gallery: 10 images

Ride: NCII Fairlane

Location: Bathurst
NSW, Australia

tickford_6 wrote:
More Grunt wrote:
I was wondering in my wondering time this morning, if you could fit AU pistons onto E series con rods? since the e series rods are .2 or so of an inch shorter than AU rods, this would be a pretty easy way of de-compressing a 4 ltr for turbo's or superchargers wouldnt it? it would also rev slightly better due to being squarer, and the FI would make up for the slightly lower torque down low.

how much compression would one loose if the stroke is reduced by that much? would it get it under the 8.5:1 mark?

If it fell too low you could shave off the head a bit to bring it back up...

wonder what the literage would be with the combo. Bet its been done if it can be done. anyone heard anything of it?


you'd lower the comp to far and create more problem then it solves.

the engine will not be any 'squarer'. that is determind by the stroke and bore. not by the installed lenght of the rod and piston


ahh but wouldn't an aduquatly shaven head raise some compression to compensate for the lower compression?? or using a polished 3.9 head to also compenstate

 

_________________

R.I.P Tobias my son.

Top
 Profile  
 
 
Posted: Thu Jun 05, 2008 12:25 am 
Getting Side Ways
Offline
User avatar

Age: 35

Posts: 1775

Joined: 10th Jul 2007

Gallery: 8 images

Ride: BFII Turbo

Power: 253 rwkw

Location: Waurn Ponds
VIC, Australia

lol the actual burning question that i was really wanting answered was can you put AU pistons on EL rods... i mean in the way they connect together.

coz without that answered its just conjecture.

Also is there a way to calculate a .2 inch drop (half a centimeter) in piston height vs how much compression lost?

and if so, how much head shave needed to bring it back to around the 8.5:1 level.

who can do the engineering physics maths thingy bit?

cos dropping to around 8:1 for FI would be ideal to get bigger boost, better than decomp plates and gaskets that can fail readily enough.

if it hasnt been done there must be a reason, i just want to hear a real reason why it hasnt.

not just probablies.

 

_________________

enough isn't enough

Top
 Profile  
 
 
 Post subject: Re: Rod length and compression
Posted: Thu Jun 05, 2008 12:35 am 
Fordmods Addict
Offline
User avatar

Age: 31

Posts: 7958

Joined: 1st Jun 2005

Gallery: 13 images

Ride: Falcon

Power: 237 rwkw

Location: Melbourne
VIC, Australia

Google "quench", and thats your reason why it's never been done.

 

_________________

ED XR8 Sprint - S-Trim, V500, 249rwkw
BF MKII F6 Tornado - 237rwkw

Top
 Profile  
 
 
 Post subject: Re: Rod length and compression
Posted: Thu Jun 05, 2008 12:36 am 
Getting Side Ways
Offline
User avatar

Age: 35

Posts: 1775

Joined: 10th Jul 2007

Gallery: 8 images

Ride: BFII Turbo

Power: 253 rwkw

Location: Waurn Ponds
VIC, Australia

tickford_6 wrote:

the engine will not be any 'squarer'. that is determind by the stroke and bore. not by the installed lenght of the rod and piston


good point this, didnt think of it both ways lol, sure enough the piston wont travel as far up but it would travel further down, creating the same swept capacity, thanks for highlighting that.

would have to make sure there is still cylinder bore half a centimeter lower than usual...

 

_________________

enough isn't enough

Top
 Profile  
 
 
 Post subject: Re: Rod length and compression
Posted: Thu Jun 05, 2008 12:41 am 
Getting Side Ways
Offline
User avatar

Age: 35

Posts: 1775

Joined: 10th Jul 2007

Gallery: 8 images

Ride: BFII Turbo

Power: 253 rwkw

Location: Waurn Ponds
VIC, Australia

Steady ED wrote:
Google "quench", and thats your reason why it's never been done.


I almost knew that it would be you who would know the reason why it wouldnt work, thanks man. clears that little wonder up.

should have just pm'd you and saved the forum space lol.

 

_________________

enough isn't enough

Top
 Profile  
 
 
Posted: Thu Jun 05, 2008 1:20 am 
Fordmods Addict
Offline
User avatar

Age: 31

Posts: 7958

Joined: 1st Jun 2005

Gallery: 13 images

Ride: Falcon

Power: 237 rwkw

Location: Melbourne
VIC, Australia

I don't know that much, only from reading books!

 

_________________

ED XR8 Sprint - S-Trim, V500, 249rwkw
BF MKII F6 Tornado - 237rwkw

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 1  [ 10 posts ] 

Who is online

Users browsing this forum: No registered users and 24 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 Wed Dec 13, 2017 12:00 am All times are UTC + 11 hours

 

 

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