compression test

[Emode]

howdy all
did a compression test on my speed today, all cylinders were within 133-136psi
just checking around, sound about right ot everyone?
also installed those extended reach colder plugs after having normal colder ones for awhile, noticed a difference, much smoother idle and response

 

[Brian MP5T]

The extended reach is standard is it not???

Besides, if you were to get a longer plug, do you not think that it would take up more area inside the cylinder and therefore make more compression (Which is not a really good thing to do on a motor that is already 9:1??)

 

[Emode]

msp came stock with extended plugs, people didnt realize this until recently, i had switched out the original plugs early for colder copper ones that werent extended.

 

[Dexter]

i THINK that pressure number sounds right...

 

[Emode]

yeah at first i got one that said like 220, and all the others were way low
then i realized i forgot to bleed the pressure the first time(wedge)

 

[Dexter]

Okay, I emphasized THINK mainly because i thought they sounded low, but I thought I just had a bad memory...

anyways, after searching:

Koolidino - So anyway, I did a compression test...Each cylinder read between 180 and 183 or so.
pdhaudio- dealer said normal compression was 175

Hmm....are you sure you did it right?

 

[BlkZoomZoom]

ENGINE COMPLETE

COMPRESSION INSPECTION [FS]



WARNING:

• Hot engines and oil can cause severe burns. Be careful not to burn yourself during removal/installation of each component.

1. Verify that the battery is fully charged.
   • Recharge it if necessary.
2. Warm up the engine to the normal operating temperature.
   
3. Stop the engine and allow it to cool off for about 10 min .
   
4. Perform "Fuel Line Safety Procedures". Leave the fuel pump relay removed.
   
5. Remove the ignition coils.
   
6. Remove the spark plugs.
   
7. Connect a compression gauge into the No.1 spark plug hole.
   
8. Fully depress the accelerator pedal and crank the engine.
   
9. Note the maximum gauge reading.
   
10. Inspect each cylinder as above.
    • If the compression in one or more cylinders is low or the compression difference between cylinders exceeds the maximum, pour a small amount of clean engine oil into the cylinder and recheck the compression.
      • If the compression increases, the piston, the piston rings, or cylinder wall may be worn and overhaul is required.
      • If the compression stays low, a valve may be stuck or improperly seated and overhaul is required.
      • If the compression in adjacent cylinders stays low, the cylinder head gasket may be damaged or the cylinder head distorted and overhaul is required.

Compression



kPa {kgf/cm<SUP>2</SUP> , psi} [rpm]

<TABLE border=2><TBODY><TR><TD rowSpan=2> Item </TD><TD rowSpan=0.0> Engine type </TD></TR><TR><TD rowSpan=0.0> FS </TD></TR><TR><TD rowSpan=0.0> Standard </TD><TD rowSpan=0.0> 1,177 {12.0, 171} [300] </TD></TR><TR><TD rowSpan=0.0> Minimum </TD><TD rowSpan=0.0> 824 {8.4, 119} [300] </TD></TR><TR><TD rowSpan=0.0> Maximum difference between cylinders </TD><TD rowSpan=0.0> 196 {2.0, 28} </TD></TR></TBODY></TABLE>

1. Disconnect the compression gauge.
   
2. Install the spark plugs.
   • Tightening torque
   • 1522 Nm {1.52.3 kgfm, 1116 ftlbf}
3. Connect the ignition coil connector.
   
4. Install the fuel pump relay.

yours seems alittle low, did you follow this procedure?

 

[Brian MP5T]

Holy Information OVERKILL!!

 

[Emode]

yeah i havent done one before, this was first time
forgot to depress gas pedal
at least this showed me that there was any big differences between cylinders
thanks for the help