Compression test readings to expect from 2.5L Skyactiv?

[buyingconstant7]

It's a lazy Sunday and I want to do something. I'm thinking I'll do a compression test on the 2014 CX-5 2.5L. It has 56,000kms on it. What compression numbers should I expect? I know how to do compression test properly, so I don't need to be educated on how to do one, I just would like a rough number, I'm guessing upwards of 200PSI?

If anyone is curious as to why I'd do this on a new(ish) car:
1) I'm oddly curious, and I'm very bored today
2) I'd like to document compression every oil change (8,000kms) and see how quickly it decreases.

 

[Kedis82ZE8]

From FSM:

Specification:
Compression [SKYACTIV-G 2.0]
Standard: 885 kPa {9.02 kgf/cm2, 128 psi} (300 rpm)
Minimum: 708 kPa {7.22 kgf/cm2, 103 psi} (300 rpm)
Maximum difference between cylinders: 150 kPa {1.53 kgf/cm2, 21.8 psi} (300 rpm)

Compression [SKYACTIV-G 2.5]
Standard: 954 kPa {9.73 kgf/cm2, 138 psi} (300 rpm)
Minimum: 763 kPa {7.78 kgf/cm2, 111 psi} (300 rpm)
Maximum difference between cylinders: 161 kPa {1.64 kgf/cm2, 23.4 psi} (300 rpm)

NOTE:
Because the SKYACTIV-G 2.0 and SKYACTIV-G 2.5 retards the intake valve closing timing, compression pressure is low.

 

[erhayes]

The CR is a static measurement taken by comparing volumes and due to valve time may differ considerable with compression gauge measurements as stated above. Ed.

 

[yrwei52]

From FSM:

Specification:
Compression [SKYACTIV-G 2.0]
Standard: 885 kPa {9.02 kgf/cm2, 128 psi} (300 rpm)
Minimum: 708 kPa {7.22 kgf/cm2, 103 psi} (300 rpm)
Maximum difference between cylinders: 150 kPa {1.53 kgf/cm2, 21.8 psi} (300 rpm)

Compression [SKYACTIV-G 2.5]
Standard: 954 kPa {9.73 kgf/cm2, 138 psi} (300 rpm)
Minimum: 763 kPa {7.78 kgf/cm2, 111 psi} (300 rpm)
Maximum difference between cylinders: 161 kPa {1.64 kgf/cm2, 23.4 psi} (300 rpm)

NOTE:
Because the SKYACTIV-G 2.0 and SKYACTIV-G 2.5 retards the intake valve closing timing, compression pressure is low.

How do you keep the engine running at 300 rpm to measure the compression?

With Atkinson cycle on SkyActiv-G engines, the compression pressure would be low, so as the effectiveness of the engine brake.

 

[buyingconstant7]

Oh right! I totally forgot about the Atkinson cycle feature. It even does this when warm? I guess it would be pretty dumb to let the engine run on 3 cylinders when taking a reading on the other 1. So I guess there is no way around it, unless you heavily toyed with the computer...

 

[GAXIBM]

Will the starter turn the engine @300rpm with all plugs out and only one cylinder gaged?

 

[Unobtanium]

Will the starter turn the engine @300rpm with all plugs out and only one cylinder gaged?

Any vehicle I've had would spin at 3-500rpm with the starter and all plugs out. Hell, they would do 300rpm with the plugs IN!

 

[yrwei52]

Will the starter turn the engine @300rpm with all plugs out and only one cylinder gaged?

Any vehicle I've had would spin at 3-500rpm with the starter and all plugs out. Hell, they would do 300rpm with the plugs IN!

Are you sure about that? That would be 5 revolutions per second using starter and hopefully it won't be smoking. I could barely do 1 revolution per second when I was hand-cranking an engine back to very old days!

 

[Unobtanium]

Are you sure about that? That would be 5 revolutions per second using starter and hopefully it won't be smoking. I could barely do 1 revolution per second when I was hand-cranking an engine back to very old days!

Every car I've compression tested, from my 302 V8 to my 2.0 SR20DE would maintain AT LEAST 300rpm* with all the plugs in. More with them out.


*Per the dash tach