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Subject: "Compression Test Question" Previous topic | Next topic
TeamDR1665Nov-22-02 02:19 PM
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#37907, "Compression Test Question"


          

I tried the search utility first, but no luck there.
I just did a compression test like was suggested back in my Operation Turbo Prep post and here's what I got:
165-155-160-160 (#1-#4, L-R)
Like I said, I'm pushing 135k, and I remember reading or hearing somewhere that 180->200 is the norm or ideal, so I'm a bit nervous. I can't say I feel the car as being any slower than when new and no matter what I do to it, it will never feel fast enough, so is this good, bad average? I'd like to try the leakdown test, but I honestly have no idea how that is done. Other than that, where do I go from here?
Thank you for humoring a newbie emoji

  

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Replies to this topic
RE: Compression Test Question, AkAicon, Nov-22-02 02:39 PM, #1
RE: Compression Test Question, TeamMetalJim, Nov-22-02 03:33 PM, #2
RE: Compression Test Question, TeamDR1665, Nov-23-02 03:52 AM, #3
      RE: Compression Test Question, TeamDR1665, Nov-23-02 11:08 AM, #4
           RE: Compression Test Question, TeamDR1665, Nov-23-02 11:09 AM, #5
                RE: Compression Test Question, SPL_Eclipse, Nov-23-02 02:51 PM, #6
                     RE: Compression Test Question, TeamDR1665, Nov-23-02 05:09 PM, #7

AkAiconNov-22-02 02:39 PM
Member since Nov 21st 2002
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#37908, "RE: Compression Test Question"
In response to Reply # 0


          

Recent compression check on my rebuilt 420a was 165-170 across the board with stock pistons

  

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TeamMetalJimNov-22-02 03:33 PM
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#37909, "RE: Compression Test Question"
In response to Reply # 0




          

Firstly - make sure the engine is warm when you do the compression test.

The numbers do look on the low side(better than mine though). You should try the leakdown to see if its due to ring wear. To do a leakdown, just pour a little oil in the spark plug hole and then test the compression. You don't need much. I usually use about an oil cap full. What this does is creates a hydraulic seal on the ring tops - and it'll make it look like you have perfect rings. If the numbers go up after the leakdown test, then the difference is how much compression loss is due to ring wear. If the numbers don't go up, then your compression loss is being caused by the headgasket or valves/valve-seats.

I'm not sure of there is an exact number on this one, but if you're loosing more than 25-30 psi from ring wear then you may want to think about re-ringing.


ride__________95 Eclipse RS : 5 speed
power________Gude cams : Jeep TB : AFX UDP : ram air : test pipe : GST catback
suspention___BOMZ F/R upper strut bars : ES inserts
sound________Kenwood KDC 5000 : Audiovox 8" sub toob - no sub amp(damnit!)
shizzle_______AutoCommand remote start : dual air horns : Caspers o2 simulator(rear)
incomming___Hurricane F/R lower strut ties : Field SFC Hyper-R
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html


95 Eclipse RS : 5 speed
14.76 @ 94.72mph
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

  

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TeamDR1665Nov-23-02 03:52 AM
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#37910, "RE: Compression Test Question"
In response to Reply # 2


          

Thanks!
I'm gonna do that leakdown test here in the next couple hours. We'll see what we shall see, huh?
Hey Jim! How hard was it to install air horns? I've always wanted to do that. That would scare the S out of people. Especially those in the lifted trucks around here who (literally) look down on tuners.

  

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TeamDR1665Nov-23-02 11:08 AM
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#37911, "RE: Compression Test Question"
In response to Reply # 3


          

NEW RESULTS!
I just finished the leak down. I redid the compression test since the engine was all warmed up this time for better results and consistency between the test conditions. Looks like I'll be checking into some of the Total Seal gapless rings in the near future...
#1-#4 (Cams->right)
160/240--155/300(pegged gauge)--175/265--265/260
Should I look into the Total Seal? How tough/expensive/much downtime will this be? TIA

  

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TeamDR1665Nov-23-02 11:09 AM
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#37912, "RE: Compression Test Question"
In response to Reply # 4


          

my bad! cylinder 4 was 165/260

  

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SPL_EclipseNov-23-02 02:51 PM
Member since Mar 11th 2002
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#37913, "RE: Compression Test Question"
In response to Reply # 5


          

holy jesus those numbers are WAY high. im not insinuating anything, but are you sure the guage and test were acurate? a 300 compression would be in the neighborhood of 15:1 or roundabouts, right? well, reagrdless even if it wasnt accurate the numbers DID go up, indicating worn rings, so you wont be in the wrong replacing them. BTW...165ish isnt too bad. the service limit (according to my chiltons) is 100.

:shhh: i do cocaine :/shhh:

  

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TeamDR1665Nov-23-02 05:09 PM
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#37914, "RE: Compression Test Question"
In response to Reply # 6


          

Maybe I just put a bit too much oil in that cylinder? I guessed on a "capful" since I use the Syntec and that's one big ass cap! She smoked like a chimney for about 15min after that. WOW. emoji
I was going to check the Chilton's, but where is it? I'm gonna have to ask the GF when she gets back into town tomorrow night, cuz she must have moved it. ("Your car stuff is always all over the place!") emoji
How much time and money am I looking at to do a ring job myself? At a mechanics? TIA

  

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