Rb25 Compression Test

[abu]

Hi

I am looking at buying a motor which has already been removed from the car but would still like a compression test carried out so I know its 100% good

Just wanting to know is there any way to compression test a motor which has been removed from the car, I have never heard of it being done but I am sure there would be some way to do it?

Its an RB25DET which has approx 80,000km on it so I would be expecting compression to be about 150 across all 6 cylinders?

Anyways any help would be appreciated

Thanks

[madbung]

Off the top of my head you could run a rubber wheel against the belts or crank pulley using a high speed drill or similar.

Removing all plugs first of course.

Or fit a pulley on the drill then run a belt to the crank pulley.

[Craved]

has it got a gearbox on it? if so just use a battery to the starter motor

[abu]

has it got a gearbox on it? if so just use a battery to the starter motor

so it will be fine to crank it with the motor sitting on say an engine crane?

It won't jolt or twist when the starter kicks will it?

Thanks

[Craved]

so it will be fine to crank it with the motor sitting on say an engine crane?

It won't jolt or twist when the starter kicks will it?

Thanks

yes yes it will jolt and try to twist.

removing the spark plugs will reduce this and allow the motor to spin easily, but this will affect the actual reading on the guage. you want all cylinders within an equal reading, the number it shows can be inaccurate

[madbung]

Geez having a stater motor still bolted up does make things just a bit simpler.

I should have asked that first hey

[Guilt-Toy]

make sure it has oil in it

[abu]

yes yes it will jolt and try to twist.

removing the spark plugs will reduce this and allow the motor to spin easily, but this will affect the actual reading on the guage. you want all cylinders within an equal reading, the number it shows can be inaccurate

Alright thanks

What reading should be expected?

make sure it has oil in it

Will do

[tridentt150v]

readings may not be quite as high or as even or as accurate, comp tests are supposed to be done when the motor is at normal operating temp. But should be an indicator.....I mean if the bore is shagged, it will still read low on that cylinder