Which of the STis have forged pistons?
#32
Piper do 3 cams 1 of them is for use with a restrictor, 270H is fast road .352 lift 264 deg 15bhp ish std motor, 285M .390 276 deg 20bhp ish std motor these cams would be far better with modified heads.Only the 270 can be run on hyd lifters and thats down to you. The reason being is that what ever extra lift, profile alteration is made to the profile of the cam lobe has to be removed from the base circle of the cam, this to make it simple would be your valve clearance, so if you have an extra .040 lift thats .040 off the B/C and your hyd lifters only have .050 opperating range it could be a rattly old bone, and anymore lift goes with out saying. Even with std solids you can go past the shim range, thick shims and high revs not good. If your like David and have a lathe you can remove the hyd part of the lifter and make a nice light solid replacement which can be machined for V/clearance, If you have large o/d solids these are same o/d as cossie and there are some nice proper solid lifter kits for these.
Steve
Steve
#33
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
Im not sure I quite follow the above?
What lifters does a 94uk 5dr turbo have as standard?? (I havent had the heads off yet ) May just get my hands on another block and work from there... I like the sound of the 285... is it driveable with that on the roads? Head work would go without saying when taking the heads off
David
[Edited by David_Wallis - 7/15/2002 11:07:46 AM]
What lifters does a 94uk 5dr turbo have as standard?? (I havent had the heads off yet ) May just get my hands on another block and work from there... I like the sound of the 285... is it driveable with that on the roads? Head work would go without saying when taking the heads off
David
[Edited by David_Wallis - 7/15/2002 11:07:46 AM]
#34
David i would guess you have the heads that have the small o/d lifters which are hyd. So you will have to make your own lifter shims which is quit simple with a lathe, just a little time consuming when shimmimg, when you have a better idea of what you have, and what you want i can help some more, if you had profiles put on to blank cams you would have no base circle/valve clearance problems but this is very expensive. The 286 will give you a rougher idle but this can be made better with mapping and by playing with valve timmimg, due to extra overlap (inet and exhaust valves open at the same time) rougher idle will occour, also your H/C on your MOT will be higher dew to unburnt fuel escaping on overlap this can be got around if it gives a prob, and check valve timmimg when cams have been fitted for optimal performance. you may have to make some larger valve pockets in your pistons. Dont let this put you of becouse its not that bad just precautions must be taken and the smiles will be big.
#37
Subaru have never released a factory production car with forged pistons.
However they do use stronger pistons in the 205Kw models which look like and are commonly called forged pistons. These Pistons use a stonger grained alloy and grind the casting lines smooth (this is also a part of balancing the pistons).
But as said before STI cars do not typically come standard with forged pistons either, but is an available option.
[Edited by submannz - 7/8/2002 11:47:37 AM]
However they do use stronger pistons in the 205Kw models which look like and are commonly called forged pistons. These Pistons use a stonger grained alloy and grind the casting lines smooth (this is also a part of balancing the pistons).
But as said before STI cars do not typically come standard with forged pistons either, but is an available option.
[Edited by submannz - 7/8/2002 11:47:37 AM]
#38
My EJ20 N/A has a standard redline of 8,000RPM and has cast pistons.
I live down the road from the Largest Subaru Wrecker probabily in the world and he has stripped thousands of STI's of all models and types and has never found a forged piston.
NOTE: STI's DO NOT Come out with standard with forged pistons, but as I mentioned before molybdenum pistons.
[Edited by submannz - 7/10/2002 11:11:13 PM]
I live down the road from the Largest Subaru Wrecker probabily in the world and he has stripped thousands of STI's of all models and types and has never found a forged piston.
NOTE: STI's DO NOT Come out with standard with forged pistons, but as I mentioned before molybdenum pistons.
[Edited by submannz - 7/10/2002 11:11:13 PM]