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help with motor rebuild 07 STI

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Old 03-06-2009, 10:27 PM
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Originally Posted by subiefan7162
My compression test. All the cylinders were at 140 except cyl 4 which was at 135. A compression test for the 07 sti according to the shop manual should be in between 182 and 142 for normal operation but should read 160 to 180 to be good. My motor isn't bad yet but it will eventually go and I figured since its going anyway why not do the full rebuild I wanted to do it anyway for what I plan to do for the turbo setup.
Just FYI, the most important thing with a compression test is the cylinder to cylinder variance. They should all be within about 5% of each other, in which case 135 is fine. What kind of compression tester did you use? Did you hold have the throttle pegged when you did the test? While there are rough guideline numbers for target compression, 140 could be perfectly fine. When I did the compression test on my car, the 'good' cylinders were closer to 120, but this was with a shitty $15 auto zone gauge, and it was obviously reading low.
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Old 03-07-2009, 09:20 AM
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Originally Posted by blacksti
135 really isnt that bad you could have def kept driving it like that ... they recommend you rebuild it if it goes under 128 but thats a nice build you have there!

so how experienced are you with rebuilding motors? because maybe 1 person in the suby tech area has actually built their own motor and im not talking about bolting your heads to your block
... im talking about a full build like youre doing and saying 1 person is being gernerous...

honestly i would call a shop that has built blocks with a good rep and ask the questions . and take it slow!!!! dont want to fuck anyhting up good luck and post pics


good luck
+1 on that. I say look for a good shop
Old 03-07-2009, 11:19 AM
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Originally Posted by subiefan7162
The rings and ring lands tend to go bad in the 07 and 08 stis because subaru used a faulty brand when they built these year motors. I think there was a recall because of it but I couldn't recall it anyway cause I have too many mods lol
your so wrong its not even funny.
Old 03-07-2009, 05:08 PM
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yeah ill definitely call a shop but i couldnt have a shop do it do to money constraints thanks for the advice on everything though. and concord how am i wrong? ive done my research on it and my buddy works for subaru plus he's like a subie guru. as far as experience blacksti, i dont have any on doing it myself but i got the know how and im definitely gonna take it slow, i got the shop manual and im gonna make sure to double check everything and hopefully my friend out here in hawaii whose from tampa can hook me up with some connects hes got back there. im hoping to learn a great deal from this experience. oh yeah and the gauge i used was the craftsman compression tester from sears and i think the only thing i didnt do according to the shop manual was to do the test while the motor was hot... that probably had my reading off from what i was looking for but either way my tuner said thats what the problem was and either way still i want to rebuild it for the power gains and to be ready for the turbo im gonna get.
Old 03-11-2009, 07:38 AM
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def goodluck with the build and from now on spend all your time here:
Built Motor Discussion - NASIOC

you will def learn alot.
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Old 03-11-2009, 10:06 AM
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do it with the motor warm will give you better results. like i said you could have kept driving the car as is but theres nothing wrong with a built motor lol good luck and keep us updated
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Old 03-11-2009, 03:54 PM
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lol will do
Old 03-11-2009, 04:04 PM
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and thanks autocannon i appreciate the link its helping me already
Old 03-11-2009, 08:34 PM
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no problem bro anytime.
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