How can I tell the difference between STI and Normal UK cams
11 February 2005, 11:11 AM
#1
How can I tell the difference between STI and Normal UK cams
I have just aquired two Cylinder heads complete with cams and valves that I believe to be STI version 5/6.
Is there anyway that I can tell for sure if they are from an STI 5/6.
Are the cams stamped differently etc or would the cam lobes be bigger etc.
I have tried comparing them to my knackered UK cams and heads and they seem identical.
Please advise you knowledgable lot!!
Is there anyway that I can tell for sure if they are from an STI 5/6.
Are the cams stamped differently etc or would the cam lobes be bigger etc.
I have tried comparing them to my knackered UK cams and heads and they seem identical.
Please advise you knowledgable lot!!
11 February 2005, 11:49 AM
#2
Scooby Regular
Join Date: Nov 2001
Location: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
Posts: 15,239
Likes: 0
Received 1 Like
on
1 Post
You need to measure the lift on the cam, possibly with a micrometer or a dial gauge.
Pavlo will be able to tell you specifics.
Pavlo will be able to tell you specifics.
11 February 2005, 06:59 PM
#3
Scooby Regular
Join Date: Jan 2002
Posts: 500
Likes: 0
Received 0 Likes
on
0 Posts
You should be able to see it easily when you look at the buckets. When they have adjustment shims on top they are non STi, when you can't see any shims on top it has to be STi.
Mark.
Mark.
11 February 2005, 08:22 PM
#4
Subaru Tuning Specialist
Join Date: Jun 2002
Location: 7.74 @179 mph 1/4 mile - road legal
Posts: 6,654
Likes: 0
Received 1 Like
on
1 Post
If they were the ones on Ebay recently then they are UK heads with overbucket shims.
If so, get your money back, I told him what they really were !
Andy
If so, get your money back, I told him what they really were !
Andy
11 February 2005, 08:46 PM
#5
Scooby Regular
Join Date: Nov 2000
Location: 32 cylinders and many cats
Posts: 18,658
Likes: 0
Received 1 Like
on
1 Post
I saw those as well, T-uk was interested, but I also noticed he said overbucket yet said STi 5/6. I think I saw your username (or one like yours) daz1 or something in the bid list even then? Hope you haven't been messed about.
11 February 2005, 08:55 PM
#6
Scooby Regular
Join Date: Dec 2004
Posts: 35
Likes: 0
Received 0 Likes
on
0 Posts
Nah mate. I managed to swap them for a pair of headlights in the end.
I desperatley needed new heads as mine are scrap due to a valve dropping. see the pics below for damage..
So I know the cams and valves are different but what about the heads will they be the same as I am planning a 2.5 build and need to know which way to go. I was thinking of different cams and uprated springs with titanium retainers anyway. So are the actual head castings the same regardless of model??
I desperatley needed new heads as mine are scrap due to a valve dropping. see the pics below for damage..
So I know the cams and valves are different but what about the heads will they be the same as I am planning a 2.5 build and need to know which way to go. I was thinking of different cams and uprated springs with titanium retainers anyway. So are the actual head castings the same regardless of model??
Trending Topics
13 February 2005, 10:35 AM
#12
Subaru Tuning Specialist
Join Date: Jun 2002
Location: 7.74 @179 mph 1/4 mile - road legal
Posts: 6,654
Likes: 0
Received 1 Like
on
1 Post
I suppose when you consider that at 6000 rpm the pistons are going up/down 100 times per second then even switching it off as soon as you could then a lot of damage is going to happen 
13 February 2005, 11:37 AM
#13
Scooby Regular
Join Date: Dec 2004
Posts: 35
Likes: 0
Received 0 Likes
on
0 Posts
The engine had done 12000 miles and 6 months after a £8.5k rebuild and a further 4000 miles after a further £2k for a turbo, fuel pump cold air feed and a remap. The car permenantly ran on Optimax
The car was recently dyno'd at 399bhp - 382 ft/lbs.
Does anyone know if the actual head casings are the same? Is it just the valves and cams that are different between STI and UK model.
It was a MY99 RB5 by the way.
Banny do the heads still have the cams?
The car was recently dyno'd at 399bhp - 382 ft/lbs.
Does anyone know if the actual head casings are the same? Is it just the valves and cams that are different between STI and UK model.
It was a MY99 RB5 by the way.
Banny do the heads still have the cams?
13 February 2005, 11:44 AM
#14
I have a set of STi 6 cams for sale which were in the 585 bhp engine if anyone is interested, also two bare heads, skimmed. www.geocities.com/harveysmith3000
13 February 2005, 04:13 PM
#15
yes i have the cams too
Originally Posted by RB5263
The engine had done 12000 miles and 6 months after a £8.5k rebuild and a further 4000 miles after a further £2k for a turbo, fuel pump cold air feed and a remap. The car permenantly ran on Optimax
The car was recently dyno'd at 399bhp - 382 ft/lbs.
Does anyone know if the actual head casings are the same? Is it just the valves and cams that are different between STI and UK model.
It was a MY99 RB5 by the way.
Banny do the heads still have the cams?
The car was recently dyno'd at 399bhp - 382 ft/lbs.
Does anyone know if the actual head casings are the same? Is it just the valves and cams that are different between STI and UK model.
It was a MY99 RB5 by the way.
Banny do the heads still have the cams?
15 May 2005, 01:27 PM
#17
Scooby Newbie
Join Date: May 2004
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
I have found 4 cams that they are supposed to be STi5 cams.
I compare them with WRX 01 cams and the difference is on lobe's size.
The lobe size on WRX cams is arround 46,5mm but the "STi" lobes are 45,5mm.
Are those measurements normal?
Thanks,
Christos
I compare them with WRX 01 cams and the difference is on lobe's size.
The lobe size on WRX cams is arround 46,5mm but the "STi" lobes are 45,5mm.
Are those measurements normal?
Thanks,
Christos
16 May 2005, 07:09 AM
#19
Scooby Newbie
Join Date: May 2004
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
Thanks Harvey,
give me some time to conclude that the cams i have are (on not) real STi cams.
No one cam specialist out there?
The fact that the STi lobe is smaller from the WRX cam lob, isn't strange?
Thanks in advance,
Christos
give me some time to conclude that the cams i have are (on not) real STi cams.
No one cam specialist out there?
The fact that the STi lobe is smaller from the WRX cam lob, isn't strange?
Thanks in advance,
Christos
16 May 2005, 08:49 AM
#20
STI and uK version 5/6 have same lift so unless you put the cams in the head and measure lift at rotation to get actual duration it's hard to tell.
The easiest way is the rest of the heads. the STI heads will have solid followers and shims underneath. UK heads have solid followers with larger shims on the top.
STI valves tend to be marked with a 3 so ID3 for inlet and ED3 for exhaust where UK valves are ID2 for inlet and ED2 for exhaust.
The easiest way is the rest of the heads. the STI heads will have solid followers and shims underneath. UK heads have solid followers with larger shims on the top.
STI valves tend to be marked with a 3 so ID3 for inlet and ED3 for exhaust where UK valves are ID2 for inlet and ED2 for exhaust.
18 May 2005, 09:40 AM
#21
Scooby Newbie
Join Date: May 2004
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
I measured the intake cams and the results were strange.
Peak cam lift (wrx cams) :9.3mm
Peak cam lift ("Sti" unknown cams) :8.3mm
max WRX cam Duration at 0.1 lift with 0.2 valve lash 258.97
max "STi" .................................................. ...... 260.68
The guy who measured the cams told me that he does not suggest to use the "Sti unknown" cams cause the acceleration of the valve would be much smaller cause the peak cam lift is 1mm smaller.
Any ideas to this?
Thanks
Christos
Peak cam lift (wrx cams) :9.3mm
Peak cam lift ("Sti" unknown cams) :8.3mm
max WRX cam Duration at 0.1 lift with 0.2 valve lash 258.97
max "STi" .................................................. ...... 260.68
The guy who measured the cams told me that he does not suggest to use the "Sti unknown" cams cause the acceleration of the valve would be much smaller cause the peak cam lift is 1mm smaller.
Any ideas to this?
Thanks
Christos
18 May 2005, 10:18 AM
#22
Scooby Regular
Join Date: Sep 2002
Location: Glasgow
Posts: 429
Likes: 0
Received 0 Likes
on
0 Posts
Christos,
For comparison here's what I've measured on STi3 cams:
Inlet -
lift=8.3mm, duration @ 10 thou=276, duration @ 50 thou=207
Exhaust -
lift=8.6mm, duration @ 10 thou=272, duration @ 50 thou=211
Measurements are on cam not valve seat so no allowance made for lash.
The 10 thou duration is, I think, the usual 'advertised' duration while the 50 thou number is the commonly used 'real' duration.
For comparison here's what I've measured on STi3 cams:
Inlet -
lift=8.3mm, duration @ 10 thou=276, duration @ 50 thou=207
Exhaust -
lift=8.6mm, duration @ 10 thou=272, duration @ 50 thou=211
Measurements are on cam not valve seat so no allowance made for lash.
The 10 thou duration is, I think, the usual 'advertised' duration while the 50 thou number is the commonly used 'real' duration.
