Author Topic: Sr20de compression  (Read 1830 times)

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Trpb

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Sr20de compression
« on: 09 January, 2015, 08:53:06 AM »
What should a healthy sr20de have per cylinder. Mines at 150psi keen to see what other motors are. I know there will be some variance ie tester and so on . Who's got psi

Nz new motor p11 99 gx



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Re: Sr20de compression
« Reply #1 on: 09 January, 2015, 09:56:34 AM »
You should google it before you ask - I found this online, probably taken from the FSM:

Measurement of Compression Pressure
1. Warm up engine.
2. Turn ignition switch off.
3. Release fuel pressure (See How to Change Fuel Filter)
4. Remove all spark plugs.
5. Disconnect distributor center cable.
6. Attach a compression tester to No. 1 cylinder.
7. Depress accelerator pedal fully to keep throttle valve wide open.
8. Crank engine (let it turn over 7 times) and record highest gauge indication.
9. Repeat the measurement on each cylinder as shown above.
Note: Always use a fully charged battery to obtain specific engine revolution.

Compression Pressure kPa (kg/cm2, psi) / RPM
Standard = 1,236 (12.6, 179) / 300
Minimum = 1,040 (10.6, 151) / 300
Difference limit between cylinders = 98 (1.0, 14) / 300

10. If cylinder compression in one or more cylinders is low, pour a small amount of engine oil into the cylinders through the spark plug hole and re-test compression.

* If adding oil helps compression, piston rings may be worn or damaged. If so, replace piston rings after checking piston.
* If pressure stays low, a valve may be sticking or seating improperly. Inspect and repair valve and valve seat.
* If compression in any two adjacent cylinders is low and if oil does not help compression, there is a leak past the gasket surface. If so, replace cylinder head gasket.


So 150 would be low, although I'd redo it again by the method above to confirm that.

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Trpb

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Re: Sr20de compression
« Reply #2 on: 09 January, 2015, 02:19:51 PM »
Hi thanks for your input I'm more trying to find out if there are variance between a
Jdm motor
Nz new motor
And years for that matter
A few of us have track cars and are trying to get them all on the same page so to speak. And I think a psi level will sort that.

More looking for data from primera owners than stuff off the web it seams to have been copied and pasted a lot.

Google is great though!

morrisman1

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Re: Sr20de compression
« Reply #3 on: 10 January, 2015, 08:53:55 AM »
If I find a compression tester that works I could do Dad's GXE, should be a good reading as the motor is well maintained.