UKSaabs

THE site for UK Saab people!
It is currently Fri Dec 14, 2018 5:11 am

All times are UTC





Post new topic Reply to topic  [ 7 posts ] 
Author Message
PostPosted: Sat Mar 10, 2018 8:19 pm 
Offline
Full Pressure Turbo

Joined: Sun Jan 20, 2013 12:45 pm
Posts: 969
Location: South Norfolk
Car Model: 9-5 DE Aero stage 3+ Quaife
I've been doing some research and I have read that some seem to have experienced excessive wear of the cylinder lining due to forged pistons being harder than the liners and there being more lateral piston movement when cold.

Has anyone experience of this? Would forged pistons in the 9-5 Aero wear the engine more quickly than stock, assuming everything else is reliable and working properly of course.

Jimbo

_________________
06 9-5 Aero Man Chilli Red stg 3+ 'RCP' no more sob
17 220d M Sport GT
04 320cd M Sport


Top
 Profile  
 
PostPosted: Sat Mar 10, 2018 10:50 pm 
Offline
Barrelling Along
User avatar

Joined: Fri Nov 23, 2007 6:13 pm
Posts: 19404
Location: Maidstone
Car Model: 9-5 Aero
Kev (soulfirer) had a set of forged pistons in his big power 9-5 aero......... they got a lot of use and they eventually needed replacing after hundreds of thousands of miles. As far as I know, the bores were OK - no reason why they shouldn't be, as most cast iron (b202 & b2*4/5) is harder than forged aluminium.
That's not to say there will not be any wear, as bores will wear over time, but I do not believe it to be excessive. I imagine the problem could be with more modern aluminium blocks with liners (materials dependent).

_________________
Rich
CC Carlsson - The colour's a secret
9-5 Aero saloon - Espresso


Top
 Profile  
 
PostPosted: Sun Mar 11, 2018 7:36 am 
Offline
Talking Turkey
User avatar

Joined: Mon Apr 02, 2007 11:52 am
Posts: 23278
Location: not in a SAAB.
Car Model: One of the first RHD 9-5s
Possibly the fact much higher power levels are involved would mean more internal wear on the engine liners?

_________________
52 9-5 2.0LPT Vector Sport B235R/GT17562
05 9-5 Aero with all the options.


Top
 Profile  
 
PostPosted: Sun Mar 11, 2018 3:41 pm 
Offline
Full Pressure Turbo

Joined: Sun Jan 20, 2013 12:45 pm
Posts: 969
Location: South Norfolk
Car Model: 9-5 DE Aero stage 3+ Quaife
I have no real desire at present to go above my current estimated stage 3+ just wanting a safe and reliable car. In any case I want a quaife before anything else now. I like the idea of lighter components, reducing inertia and improving throttle response etc. Would consider a lightened flywheel if I ever get the quaife done.

Cheers

Jimbo

_________________
06 9-5 Aero Man Chilli Red stg 3+ 'RCP' no more sob
17 220d M Sport GT
04 320cd M Sport


Top
 Profile  
 
PostPosted: Wed Mar 14, 2018 9:18 am 
Offline
Full Pressure Turbo

Joined: Sun Jan 20, 2013 12:45 pm
Posts: 969
Location: South Norfolk
Car Model: 9-5 DE Aero stage 3+ Quaife
So having done some more eading up it seems actually that forged pistons are generally heavier than cast as I'm sure most of you knew :wall:

This leads me to asking is it still a good idea to change the rods at the same time as heavier pistons will create more kinetic energy/stress on the pistons as they hit TDC then start on the down stroke?

Jimbo

_________________
06 9-5 Aero Man Chilli Red stg 3+ 'RCP' no more sob
17 220d M Sport GT
04 320cd M Sport


Top
 Profile  
 
PostPosted: Wed Mar 14, 2018 11:40 am 
Offline
UKS Veteran
User avatar

Joined: Wed May 12, 2004 9:46 pm
Posts: 14608
Location: Mulbarton,Norfolk
Car Model: TTid's only now :-(
Shouldn't it be the really hard piston rings touching the bore, not the soft aluminium (or slightly harder forged aluminium) piston?.....

_________________
What we need are more people who specialise in the impossible


Top
 Profile  
 
PostPosted: Wed Mar 14, 2018 12:22 pm 
Offline
Full Pressure Turbo

Joined: Sun Jan 20, 2013 12:45 pm
Posts: 969
Location: South Norfolk
Car Model: 9-5 DE Aero stage 3+ Quaife
To put it another way imagine holding a heavy mallet and thrusting it up into the air then pulling it down sharply and repeating this action a few times as quickly as possible. Then see how your arm/shoulder feel.

Jimbo

_________________
06 9-5 Aero Man Chilli Red stg 3+ 'RCP' no more sob
17 220d M Sport GT
04 320cd M Sport


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 7 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 6 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

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group

follow UKSaabs on Twitter



UKSaabs silhouette logo images by Mark Green www.greenphotos.com
"subsilver2" slightly bodged by UKSaabs for our own use.

:: Disclaimer ::
Comments posted here are the views of their individual authors and are not necessarily shared by the owners of this Web site.
Authors assume all responsibility for comments posted here.

UKSaabs The biggest and best privately owned UK based independent Saab forum for all SAAB enthusiasts.
Whilst we encourage our users to support our advertisers the site wishes to remain independent and therefore does not endorse any particular advertiser(s)
UKSaabs is not affiliated with Saab Cars UK or Saab Automobile AB