 decent compression numbers? |
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| dlo914 |
 Sep 28 2004, 02:46 AM
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#1
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Whatchu' lookin' at?!?!  Group: Members Posts: 3,432 Joined: 6-September 04 From: San Gabriel, CA Member No.: 2,697  |
ran a compression test today: 100/100/100/115. (1st - 4th cylinder) should these compression numbers be higher in the 130 range? or am i gonna be fine? prossibly replace piston rings? valve adjustment?
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| thesey914 |
Sep 28 2004, 05:23 AM
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#2
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Senior Member Group: Benefactors Posts: 1,155 Joined: 1-January 03 From: Staffordshire -England Member No.: 66  |
The numbers sound similar to mine IIRC. They're all fairly similar to each other also which is good, If you had one cylinder at 75psi then you could worry. The CR is pretty low on these engines. If you haven't adjusted the valves then that would be a good thing and see if the numbers are any different. If you add a teaspoon of oil to the cylinders and the numbers improve then the rings may be worn.
I reckon they sound pretty healthy. |
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| Gint |
Sep 28 2004, 07:34 AM
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#3
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Mike Ginter Group: Admin Posts: 16,082 Joined: 26-December 02 From: Denver CO. Member No.: 20 Region Association: Rocky Mountains |
What's your altitude?
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| scruz914 |
Sep 28 2004, 10:12 AM
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#4
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Senior Member Group: Members Posts: 815 Joined: 26-February 04 From: Santa Cruz, CA Member No.: 1,724 |
What engine do you have?
I have a 2.0 built up with bigger P&Cs (PPO did the rebuild, don't know the actual size of the engine). My compression just tested at 150, 155, 150, 160. I thought that those numbers were pretty damn good. Since yours are all close to each other you are OK. The recommendation to adjust the valves is good but they would all have to be tight to get such an even reading. Higher readings with a little oil down the sparkplug hole will mean worn rings. If that is the case you could try some of the snake oil avaliable. It could give you a little longer service with higher compression. -Jeff |
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| dlo914 |
Sep 28 2004, 07:47 PM
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#5
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Whatchu' lookin' at?!?! Group: Members Posts: 3,432 Joined: 6-September 04 From: San Gabriel, CA Member No.: 2,697 |
ive got a FI 1.8 in the 74', the PO said the heads were rebuilt, but the bottom end prolly just needs new piston rings. the school shop hasnt had the time to adjust the valves, hopefully they'll adjust them. And since it's at the school shop i'm getting the entire car inspected for (IMG:style_emoticons/default/mueba.gif) free. (IMG:style_emoticons/default/biggrin.gif)
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| nebreitling |
Sep 28 2004, 09:34 PM
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#6
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Member Emeritus Group: Members Posts: 3,314 Joined: 26-March 03 From: San Francisco Member No.: 478 |
i think i'd rather have my 914 sitting in a snow/salt mixture than a school shop....
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