wrx heads vs sti heads
09 January 2011, 01:53 AM
#2
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as far as what i can gather from what has been posted on this forum the only difference is in the cams....
more aggresive....
I'm after the same info for a V5 lol
more aggresive....
I'm after the same info for a V5 lol
09 January 2011, 12:22 PM
#4
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Hello Mate,
The wrx heads usualy have hyraulic lifters and the sti's have solid shimmed lifters, the solid lifters are better at higher rpm.
I know the cams are different but do not know how different, I will have to measure mine when I get them and compare them to the wrx cams.
Regards,
Greg
The wrx heads usualy have hyraulic lifters and the sti's have solid shimmed lifters, the solid lifters are better at higher rpm.
I know the cams are different but do not know how different, I will have to measure mine when I get them and compare them to the wrx cams.
Regards,
Greg
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09 January 2011, 06:33 PM
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dont think theres much difference tbh, the v1 sti's are basically wrx's with a few cosmetic parts as far as i know and i think that pretty much goes for v2's as well
Last edited by P1Drifter; 09 January 2011 at 06:35 PM.
09 January 2011, 10:08 PM
#11
Joz and Prodriverules - i know a little bit about the EJ20's lol
As said above,the Version 2 WRX/STi both share a common head casting,valves,springs and hyraulic lifters - but the STi has lightweight hydraulic lifters and cams with a higher lift and slightly longer duration.
The main drawback with these heads tuning wise is they can can suffer from 'lifter pump-up/jacking' at higher power levels/rpm. This is one of the reasons the STi Version 2 RA and STi Version 3 onwards went over to solid lifters with under bucket shims.
Mick
As said above,the Version 2 WRX/STi both share a common head casting,valves,springs and hyraulic lifters - but the STi has lightweight hydraulic lifters and cams with a higher lift and slightly longer duration.
The main drawback with these heads tuning wise is they can can suffer from 'lifter pump-up/jacking' at higher power levels/rpm. This is one of the reasons the STi Version 2 RA and STi Version 3 onwards went over to solid lifters with under bucket shims.
Mick
09 January 2011, 10:11 PM
#12
Joz and Prodriverules - i know a little bit about the EJ20's lol
As said above,the Version 2 WRX/STi both share a common head casting,valves,springs and hyraulic lifters - but the STi has lightweight hydraulic lifters and cams with a higher lift and slightly longer duration.
The main drawback with these heads tuning wise is they can can suffer from 'lifter pump-up/jacking' at higher power levels/rpm. This is one of the reasons the STi Version 2 RA and STi Version 3 onwards went over to solid lifters with under bucket shims.
Mick
As said above,the Version 2 WRX/STi both share a common head casting,valves,springs and hyraulic lifters - but the STi has lightweight hydraulic lifters and cams with a higher lift and slightly longer duration.
The main drawback with these heads tuning wise is they can can suffer from 'lifter pump-up/jacking' at higher power levels/rpm. This is one of the reasons the STi Version 2 RA and STi Version 3 onwards went over to solid lifters with under bucket shims.
Mick
10 January 2011, 06:53 PM
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i was under the impresion that the sti valves were injected with some thing to also keep the heat down.
not the sti v2. but the v3on
as this was why i got my sti v4 heads.
and this was why also they can take 500bhp no issues at all.
not the sti v2. but the v3on
as this was why i got my sti v4 heads.
and this was why also they can take 500bhp no issues at all.
10 January 2011, 09:19 PM
#18
Some Version 5~6 heads do suffer from cracks radiating out from the spark plug thread towards the valve seats - this is normally caused by the spark plug not reaching the end of the thread in the cylinder head ( usually about 2~3 threads shy ) and the open thread is exposed to the flame front.
You can machine the spark plug seat in the head to ensure the spark plug comes fully to the end of the thread on a non cracked head to prevent this happening.
The hair line cracks dont seem to affect the integrity of the heads/valve seats though - not personally seen a tipped/loose valve seat yet.
Mick
You can machine the spark plug seat in the head to ensure the spark plug comes fully to the end of the thread on a non cracked head to prevent this happening.
The hair line cracks dont seem to affect the integrity of the heads/valve seats though - not personally seen a tipped/loose valve seat yet.
Mick
03 March 2012, 11:31 PM
#21
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call me an idiot but how do you tell the difference between hydraulic and solid lifters?. ive aquired allegedly v2 type ra heads and dont know how to tell. then i went onto tinternet and noticed ra heads that came up as images were all covered in crosshatching and mine arnt. mine do have the cloverleaf combustion chambers though
04 March 2012, 10:15 AM
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call me an idiot but how do you tell the difference between hydraulic and solid lifters?. ive aquired allegedly v2 type ra heads and dont know how to tell. then i went onto tinternet and noticed ra heads that came up as images were all covered in crosshatching and mine arnt. mine do have the cloverleaf combustion chambers though
