which pistons
15 April 2012, 12:30 PM
#1
Scooby Regular
Thread Starter
which pistons
as some of you know i blew my 5 speed up on the rolling road last week ive just bought a six speed and all the prop diff hubs etc but am thinking if its going to be in bits anyway why not change the pistons etc now i want to run 400ish got the turbo front mount intercooler injecters feul pump etc fitted already but have been told the pistons might fail as i have no idea what the tolerances of the parts are what do i need
15 April 2012, 01:19 PM
#3
Scooby Regular
Thread Starter
its a 2.5 open deck im on the hunt for a cheap 2.5 engine so i can have it closed well they do a cnc cut friction fit inserts for them supposed to be a lot better than pinning them costs like 1700 though but they recon they will stand 650 bhp ok thats my target but for now i just want to run my standard engine at 400ish
15 April 2012, 01:28 PM
#5
i thought it was about 600 quid to have the block pinned? personally if i was going to run over 450 ish on a 2.5 then i'd look at getting it relinered as the 2.5 liners are thin and balloon at high power. but then at the cost of relinering or converting to cdb i'd go with a 2ltr cdb for reliability
Trending Topics
15 April 2012, 02:02 PM
#9
Scooby Regular
Join Date: Dec 2010
Posts: 3,241
Likes: 0
Received 0 Likes
on
0 Posts
The 2.5 is not an open deck, it's a semi closed deck. pinning the liners is more than enough for 400-450 although id also want forged rods at over 400hp. The liners should be fine at that power also. Going over 500hp will be expensive and not worth it in a road car imho.
15 April 2012, 07:24 PM
#11
Scooby Regular
Thread Starter
The 2.5 is not an open deck, it's a semi closed deck. pinning the liners is more than enough for 400-450 although id also want forged rods at over 400hp. The liners should be fine at that power also. Going over 500hp will be expensive and not worth it in a road car imho.
15 April 2012, 08:21 PM
#13
the standard 2.5 pistons are very poor, 380's about the upper limit on them but some people do get away with running 400. no need to pin the liners if your not going higher than 450. at 450 i'd say manley rods and wiseco pistons would see you right
15 April 2012, 08:48 PM
#14
Instructing with fear
iTrader: (31)
Join Date: Feb 2007
Location: Www.Extreme-rally.co.uk
Posts: 5,101
Likes: 0
Received 1 Like
on
1 Post
Speak to A.p.i or Enginetuner for advice on the best route and parts to use as they are the most experienced when it comes to building engines. Listening to just members advice on here could cost you a fortune if it goes wrong.......
15 April 2012, 10:31 PM
#17
Scooby Regular
Thread Starter
but ive been told the power output and torque on a 2.5 closed deck will far exceed the 2.1 theres posts on here of ej25 reaching 800bhp with the right crank rods and pistons on a closed deck and the engine build cost is around 3200 i think thats quite cheap for the power not to say im going to do that because i actually use the car at weekends lol when its working anyway ive had it 9 weeks its spent 5 of them off the road already i want 420bhp safe and if it will cost less than 1500 im a happy man
15 April 2012, 10:39 PM
#18
Moderator
iTrader: (4)
Join Date: Jul 2004
Location: The Terry Crews of moderation. P P P P P P POWER!!
Posts: 18,687
Likes: 0
Received 0 Likes
on
0 Posts
Stadard block ok at sub 500 on a 2.5.
You'll need upgraded pistons (try Supertech) upgraded Rods (I have APi ones) and better head studs (I have Api 11mm ones)
Suggest you speak to David at APi for the low down.
You'll need upgraded pistons (try Supertech) upgraded Rods (I have APi ones) and better head studs (I have Api 11mm ones)
Suggest you speak to David at APi for the low down.
16 April 2012, 12:41 PM
#19
Former Sponsor
iTrader: (4)
Join Date: Jul 2003
Location: @Junc 12, M40 Warwicksh; 01926 614522 CV33 9PL -Use 9GX for Satnav. South Mids Alcatek ECu dealer
Posts: 6,377
Likes: 0
Received 3 Likes
on
3 Posts
The 2.5 is not an open deck, it's a semi closed deck. pinning the liners is more than enough for 400-450 although id also want forged rods at over 400hp. The liners should be fine at that power also. Going over 500hp will be expensive and not worth it in a road car imho.
EJ255 WRX block is open deck.........................
16 April 2012, 12:45 PM
#20
Former Sponsor
iTrader: (4)
Join Date: Jul 2003
Location: @Junc 12, M40 Warwicksh; 01926 614522 CV33 9PL -Use 9GX for Satnav. South Mids Alcatek ECu dealer
Posts: 6,377
Likes: 0
Received 3 Likes
on
3 Posts
Running a 2.5 above 500 hp is:
A: unwise
B: expensive [ as in VERY ]
C: unreliable
For many reasons. Stay with 2.1 or 2.33 for that power level.
A: unwise
B: expensive [ as in VERY ]
C: unreliable
For many reasons. Stay with 2.1 or 2.33 for that power level.
16 April 2012, 04:02 PM
#23
Scooby Regular
Join Date: Dec 2010
Posts: 3,241
Likes: 0
Received 0 Likes
on
0 Posts
Thread
Thread Starter
Forum
Replies
Last Post
Matt_182
Wheels, Tyres & Brakes
19
07 October 2015 01:05 PM
bluebullet29
General Technical
9
05 October 2015 02:17 PM
