What's the difference between- wrx and sti engines in classics?
#1
Scooby Regular
Thread Starter
Join Date: Aug 2009
Location: northants
Posts: 365
Likes: 0
Received 0 Likes
on
0 Posts
What's the difference between- wrx and sti engines in classics?
Sorry im new, unsure if this subject has come up before, im sure is has, can anybody give me some links so i can read it myself?
Or if anybody knows, please fill me in.
Cheers
Or if anybody knows, please fill me in.
Cheers
#3
Scooby Regular
iTrader: (18)
Join Date: Jul 2007
Location: Guildford Surrey
Posts: 693
Likes: 0
Received 0 Likes
on
0 Posts
On the pre '96 there is not much difference between the 2 at all.
All the pre 96 heads have hydraulic valve lifters.
On the 97/98 (v3/v4) the sti's had forged pistons as standard and under bucket shims on the heads/valves, with better cam profiles.
The 97/98 WRX and Uk heads had large above bucket shims.
On the 99/00 the heads were revised again with different castings, cams and inlet manifolds, with low compression pistons and rear thrust cranks.
If buying a second hand complete engine there is no way to tell from the outside whether the engine has forged pistons, unless you had access to a bore scope type camera.
For heads/valves/cams the rocker covers will need to be removed to check.
Reliabilty wise they are all the same as its the big ends that go normally, before pistons/heads on the lower/medium powered cars.
All the cranks, conrods and bearings on the classic engines are the same except for v5/v6 which had rear thrust blocks and cranks, but not really improved reliabilty.
Correct me if I am wrong.
All the pre 96 heads have hydraulic valve lifters.
On the 97/98 (v3/v4) the sti's had forged pistons as standard and under bucket shims on the heads/valves, with better cam profiles.
The 97/98 WRX and Uk heads had large above bucket shims.
On the 99/00 the heads were revised again with different castings, cams and inlet manifolds, with low compression pistons and rear thrust cranks.
If buying a second hand complete engine there is no way to tell from the outside whether the engine has forged pistons, unless you had access to a bore scope type camera.
For heads/valves/cams the rocker covers will need to be removed to check.
Reliabilty wise they are all the same as its the big ends that go normally, before pistons/heads on the lower/medium powered cars.
All the cranks, conrods and bearings on the classic engines are the same except for v5/v6 which had rear thrust blocks and cranks, but not really improved reliabilty.
Correct me if I am wrong.
Last edited by Brett_555_Sti; 01 November 2009 at 06:54 PM. Reason: added info
#5
Scooby Regular
iTrader: (18)
Join Date: Jul 2007
Location: Guildford Surrey
Posts: 693
Likes: 0
Received 0 Likes
on
0 Posts
No difference to the rods on the classics AFAIK, that only came in on the later newage cars. Yours would be the version 2 '96, so should have hydraulic lifters with ribs and DOHC 16 VALVE on the rocker covers, if its the original engine.
#6
Scooby Regular
iTrader: (3)
Join Date: Aug 2000
Location: 1600cc's of twin scroll fun :)
Posts: 25,565
Likes: 0
Received 2 Likes
on
2 Posts
As Brett has said, rods are all the same, these normally are one of the first things to let go when going for big power, nice hole in your block as a result big end bearings are due to several issues, oil starvation being the biggest due to oil pumps/incorrect oil filling procedure.
Tony
Tony
#7
Scooby Regular
Thread Starter
Join Date: Aug 2009
Location: northants
Posts: 365
Likes: 0
Received 0 Likes
on
0 Posts
interesting, so changing the oil pump maybe an idea on a engine that's already out?
what's the correct procedure in filling with oil then? maybe disconnecting the crank sensor and priming it by turning the engine over?
what's the correct procedure in filling with oil then? maybe disconnecting the crank sensor and priming it by turning the engine over?
Trending Topics
#8
checking the screws on the back of the pump are tight is always a good thing
they tend to work loose ans bye bye engine. two of mine were loose when i had my cam belt changed.
they tend to work loose ans bye bye engine. two of mine were loose when i had my cam belt changed.
#10
Scooby Regular
Thread Starter
Join Date: Aug 2009
Location: northants
Posts: 365
Likes: 0
Received 0 Likes
on
0 Posts
ok, so i may aswell get myself a wrx engine to keep me going, instead of paying out more for an sti one, only want 300bhp tops.
this wont be my everyday car, so would this be achievable safely?
this wont be my everyday car, so would this be achievable safely?
#12
Scooby Regular
iTrader: (18)
Join Date: Jul 2007
Location: Guildford Surrey
Posts: 693
Likes: 0
Received 0 Likes
on
0 Posts
So it does not matter if you get a complete 97/98 engine just use your old wiring and coil packs, it all fits straight on.
#13
Scooby Regular
iTrader: (50)
Join Date: Jan 2009
Location: in my car
Posts: 1,012
Likes: 0
Received 0 Likes
on
0 Posts
Just out of interest if pre- 96 sti and wrx's have the same heads, how come the sti /wrx ra , has a higher rev limit , just i have a pp chip/ecu from a wrx ra with the higher rev limit, fitted in my 95 wrx and was told not to rev it past 7000rpm as the hydraulic valve lifters can't keep up past 7000 rpm, not that i want to rev it past that , just wondered whats different , cheers
#14
Scooby Regular
iTrader: (1)
Just out of interest if pre- 96 sti and wrx's have the same heads, how come the sti /wrx ra , has a higher rev limit , just i have a pp chip/ecu from a wrx ra with the higher rev limit, fitted in my 95 wrx and was told not to rev it past 7000rpm as the hydraulic valve lifters can't keep up past 7000 rpm, not that i want to rev it past that , just wondered whats different , cheers
As you said, Hydraulic lifters can pump up at higher sustained rpm's but the Early STi's with Hydraulic heads have lightweight hydraulic lifters fitted - each one is approx 10g lighter (when stripped and cleaned) than the WRX one's - that makes for a nice weight saving on the valvetrain.
STi Version 2 RA had Top hat Inner shims instead of hydraulic lifters.
Mick
#15
i've got a version 1 sti wagon(no.120/200).it is a s.c.b with standard pistons but uprated rods and uprated head's(lifters etc.) to allow for the higher rpm(has a different ecu to the wrx) and it boosts .2 higher than a wrx,that's standard from the factory(apparently also the engines were hand built there).also there is something about the gearbox that isn't wrx aswell(according to the mechanic at subaru)
mik
mik
#18
Scooby Regular
Join Date: Dec 2012
Location: England
Posts: 282
Likes: 0
Received 0 Likes
on
0 Posts
Intake Manifolds on V1/2 can't directly interchange with v3/4 directly as the tps and idle valve are different but could be used if modded
Last edited by jason_2013; 06 February 2013 at 10:37 PM. Reason: typo
#19
Scooby Regular
Join Date: Dec 2012
Location: England
Posts: 282
Likes: 0
Received 0 Likes
on
0 Posts
V2 sti and wrx cams are the same. Sti Ra cams are better.
So best choice would be to fit a v3/4 sti engine and modify the inlet manifold to fit= headache or use your V2 intake manifold which restricts you using a front entry turbo without modding again and also the slanty intercooler ain't too good. Or find a genuine sti V2 ra engine whIch is closed deck block and better heads. Remembering also that changing things can lead to a remapped ecu = more money.
So best choice would be to fit a v3/4 sti engine and modify the inlet manifold to fit= headache or use your V2 intake manifold which restricts you using a front entry turbo without modding again and also the slanty intercooler ain't too good. Or find a genuine sti V2 ra engine whIch is closed deck block and better heads. Remembering also that changing things can lead to a remapped ecu = more money.
#20
Scooby Regular
iTrader: (2)
Join Date: Aug 2011
Location: london
Posts: 275
Likes: 0
Received 0 Likes
on
0 Posts
Hi guys,
I know this is a very old thread, but I've just got a version 2 wrx wagon.
The person I got it off, said it seems as if the engine has been rebuilt at some stage of its life.
The side covers say 4 cam 16 valve on them, and the inlet manifolds have a fifth injector hole ( so I was told & shown )
I just want to try and get some idea about the engine, as it didn't come with much history.
It's a jdm, so all the pre uk service history is in Japanese.
It's also fitted with a z4 ecu, and a td05 turbo.
Any help and advice would be much appreciated, as I also own a hawkeye Sti spec d.
But I know what's what with that one.
I know this is a very old thread, but I've just got a version 2 wrx wagon.
The person I got it off, said it seems as if the engine has been rebuilt at some stage of its life.
The side covers say 4 cam 16 valve on them, and the inlet manifolds have a fifth injector hole ( so I was told & shown )
I just want to try and get some idea about the engine, as it didn't come with much history.
It's a jdm, so all the pre uk service history is in Japanese.
It's also fitted with a z4 ecu, and a td05 turbo.
Any help and advice would be much appreciated, as I also own a hawkeye Sti spec d.
But I know what's what with that one.
Thread
Thread Starter
Forum
Replies
Last Post