Piston advice please - Alfa Romeo Forum
You are currently unregistered, register for more features.    
Tuning & Upgrades Discuss performance enhancements for your Alfa Romeo

 3Likes
  • 3 Post By Gertie
 
Thread Tools
(Post Link) post #1 of 7 Old 11-02-18 Thread Starter
Status: -
AO Member
 
Join Date: Nov 2016
County: -
Posts: 137
Piston advice please

I had in mind to change my 3.0 to 2.8 using the 2.5 crank and con rods .
Now with these it will have a shorter stroke with this in mind i was wondering if its possible to use another cars pistons and rings if the same bore if they dont hit the valves.
as i have been given 6x pistons and rings from a turbo car new and 93mm bore which is the same as alfa 3.0 bore and the pin is 22mm.
If the dimensions all add up i cant see any reason why i cant use them..

So please could i have some advice if they will or will not work


Thanks
Overkill is offline  
Sponsored Links
Advertisement
 
Status: skint!
AO Silver Member
 
cannotstop's Avatar
 
Join Date: Aug 2009
Location: Ireland
County: Dublin
Posts: 1,489
Garage
I have to ask, why do you want to reduce displacement ?
cannotstop is offline  
(Post Link) post #3 of 7 Old 11-02-18 Thread Starter
Status: -
AO Member
 
Join Date: Nov 2016
County: -
Posts: 137
Quote:
Originally Posted by cannotstop View Post
I have to ask, why do you want to reduce displacement ?
to be able to run turbo at higher boost pressure
Overkill is offline  
Status: Quo!
AO Silver Member
 
alfaitalia's Avatar
 
Join Date: Jan 2010
Location: United Kingdom
County: West Sussex
Posts: 2,588
Why not just lower the compression on the engine you have?...or not run quite so much boost...it all add up to the same. There is "no replacement for displacement"!
Higher compression/capacity and less boost will make it a nicer driver when your are not racing/caning it...which in the real world is most of the time for most folks.
alfaitalia is offline  
Status: -
AO Member
 
_Petar_'s Avatar
 
Join Date: Feb 2017
Location: Belgrade
County: -Serbia
Posts: 37
Find posts from turbonutter he did turbo conversion on busso. You have to try with other pistons, or find dimension of busso pistons and compare them with pistons that you got. You have to pay attention on piston crown height or Piston-Deck Clearance.
_Petar_ is offline  
Status: -
AO Silver Member
 
Join Date: Nov 2013
Location: United Kingdom
County: Carmarthenshire
Posts: 3,982

Member car:

Alfa 156 Gta

Quote:
Originally Posted by Overkill View Post
I had in mind to change my 3.0 to 2.8 using the 2.5 crank and con rods .
Now with these it will have a shorter stroke with this in mind i was wondering if its possible to use another cars pistons and rings if the same bore if they dont hit the valves.
as i have been given 6x pistons and rings from a turbo car new and 93mm bore which is the same as alfa 3.0 bore and the pin is 22mm.
If the dimensions all add up i cant see any reason why i cant use them..

So please could i have some advice if they will or will not work


Thanks
its not really as east as that in all honesty.. to run higher boost you need a better piston crown or forged pistons which will take a higher load with less expansion.. its not just about compression ratio but crown design flame spread etc piston crown to first ring land and other things like that that will allow safe use of higher boost.. if it was me i would run either crank 2.8 or 3.0 but get a custom set of pistons made at around 500/600 quid designed for the application
if the other turbo piston fit with the correct pin height then you can always machined valve pockets if the crown is a suitable thickness
maxiboy wales is offline  
Status: Race cars in progress
AO Silver Member
 
Gertie's Avatar
 
Join Date: Oct 2007
Location: South Africa
County: Gauteng
Posts: 5,991
Garage
Quote:
Originally Posted by _Petar_ View Post
Find posts from turbonutter he did turbo conversion on busso. You have to try with other pistons, or find dimension of busso pistons and compare them with pistons that you got. You have to pay attention on piston crown height or Piston-Deck Clearance.
Turbonutter went straight 2.5 crank with 3.0 pistons and conrods. The CR is then 7.5:1 low. He boosts 1.5 bar

Making other pistons fit is doable but yeah a lot of research and measuring is needed if you don't want to fork out big cash for Wossner forged pistons or the like

Like in the 2.0TS you can either use 1995 BMW 325 pistons (4 of the 6 ) or Nissan 180DE pistons for N/A or Nissan 180DET pistons for boost
(The 2.0TS is after all a stroked 1.8 - like the 3.2 is a stroked 3.0 )

Last edited by Gertie; 09-03-18 at 07:20.
Gertie is offline  
Reply

Go Back   Alfa Romeo Forum > Supported Alfa Romeo Models > Technical & Vehicle Assistance > Tuning & Upgrades

Tags
advice , piston

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome