Cylinder heads?
23 October 2005, 07:07 PM
#1
Scooby Regular
Thread Starter
Join Date: Jun 2005
Location: West of Scotland
Posts: 207
Likes: 0
Received 0 Likes
on
0 Posts
Cylinder heads?
Can anyone tell me, or tell me where to look for info on cylinder heads ie what the differences are between sti v2,v3,v4,v5... and cam profiles etc
Basically i'm looking for the good points and bad points for all the versions.
Kenny
Basically i'm looking for the good points and bad points for all the versions.
Kenny
23 October 2005, 07:30 PM
#2
Referring to STi heads only.
As far as I know there is nothing special with ver 1 and 2 head assemblies. Hydraulic.
Ver 3 and 4 heads are the same (as each other) and popular with modders and sought after. I understand that ver 3 cams are more aggressive than ver 4. I do not know the cam detail but I hope someone with more knowledge will come along with more factual information, particularly in respect of valve lift. Bucket and shim.
Ver 5 and 6 heads and cams are the same (as each other) and the combustion chamber has a different capacity and shape to the ver 3 and 4. I have used ver 6 heads and cams to good effect in the past. Bucket and shim.
Many ver 5 and 6 heads have a hair line cracks from the plug hole to the inlet valve seat. This does not effect performance, certainly in the short term.
I have not seen any ver 3 and 4 heads with these cracks but plenty 5 and 6.
As far as I know there is nothing special with ver 1 and 2 head assemblies. Hydraulic.
Ver 3 and 4 heads are the same (as each other) and popular with modders and sought after. I understand that ver 3 cams are more aggressive than ver 4. I do not know the cam detail but I hope someone with more knowledge will come along with more factual information, particularly in respect of valve lift. Bucket and shim.
Ver 5 and 6 heads and cams are the same (as each other) and the combustion chamber has a different capacity and shape to the ver 3 and 4. I have used ver 6 heads and cams to good effect in the past. Bucket and shim.
Many ver 5 and 6 heads have a hair line cracks from the plug hole to the inlet valve seat. This does not effect performance, certainly in the short term.
I have not seen any ver 3 and 4 heads with these cracks but plenty 5 and 6.
23 October 2005, 08:10 PM
#3
Scooby Regular
Thread Starter
Join Date: Jun 2005
Location: West of Scotland
Posts: 207
Likes: 0
Received 0 Likes
on
0 Posts
What's the deal with manifolds and the "phase" that goes with it? Is it possible to interchange them or do you have to swap manifolds?
At what point do the early heads ie V2 become a limiting factor be it torque, power usable rev range etc?
My car is a v2 sti ra in case you hadn't guessed
Kenny
At what point do the early heads ie V2 become a limiting factor be it torque, power usable rev range etc?
My car is a v2 sti ra in case you hadn't guessed
Kenny
23 October 2005, 09:52 PM
#4
Scooby Regular
You can fit any heads up to V4 to your engine and still use the same or phase 1.5 (V3+4) inlet manifold.
V5+6 heads will fit but you will need to use a phase 2 manifold as the bolt patern is different.
Swapping the manifolds is made more complicated by the idle stepper motor on the phase 2.
V5+6 heads will fit but you will need to use a phase 2 manifold as the bolt patern is different.
Swapping the manifolds is made more complicated by the idle stepper motor on the phase 2.
Thread
Thread Starter
Forum
Replies
Last Post
Mattybr5@MB Developments
Full Cars Breaking For Spares
12
18 November 2015 07:03 AM
