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R32 Gtr Cylinder Compression Values

PhilGTR

By PhilGTR,
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PhilGTR Rising Star

PhilGTR

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Hi Guys,

Im planning to buy an 1990 r32 GTR. and I am having the engine compression tested. But im not sure what the values should be in PSI. Can someone please help? Thanks in advance!

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Abo Bob Grand Master

Abo Bob

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There has been a couple of threads on this in the last few weeks.

A leak down test is more informative than a compression test.

Also, it's more important that the compression is even than that it is a particular psi on a particular gaugue on a particular day with a particular battery level with whatever temperature the engine is.

All of those things affect the reading.

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PhilGTR Rising Star

PhilGTR

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Thanks for your reply, i got the results in and the compression in each cyclinder is as follows: 90 75 90 75 90 90. The guys at the workshop reckon this is okay. But like you said its pretty even. So should this be a worry at all?

There has been a couple of threads on this in the last few weeks.

A leak down test is more informative than a compression test.

Also, it's more important that the compression is even than that it is a particular psi on a particular gaugue on a particular day with a particular battery level with whatever temperature the engine is.

All of those things affect the reading.

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Amaru Veteran

Amaru

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Thanks for your reply, i got the results in and the compression in each cyclinder is as follows: 90 75 90 75 90 90. The guys at the workshop reckon this is okay. But like you said its pretty even. So should this be a worry at all?

If the compression test was conducted properly (warm engine, wide open throttle when cranking) then those results are pretty poor and the engine is fairly worn out. I believe Nissan specifications say 130 - 170psi.

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PhilGTR Rising Star

PhilGTR

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WHat do you mean by wide open throttle when cranking? This GTR also has a worn out clutch would that affect the reults at all?

If the compression test was conducted properly (warm engine, wide open throttle when cranking) then those results are pretty poor and the engine is fairly worn out. I believe Nissan specifications say 130 - 170psi.

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GTRsean Grand Master

GTRsean

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Engine should be adequately warmed, fuel pump fuse taken out, throttle floored and crank engine until gauge doesn't move. 8 or so compression strokes.

from nissan manual

new 171psi

normal 160psi

limit 128psi

14psi max variance between cylinders.

I tested mine and got 175 175 175 165 170 173psi, 1992 GTR

It was higher than stock? Could it be from carbon in the cylinders increasing the compression ratio?

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RellikZephyr Proficient

RellikZephyr

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when i got mine tested 1990 GTR

i got 140 140 135 140 135 140

which is ok for one thats done 100k little low but even so...

and as far as i understand u dont wanna go below 130

i dont know the whole deal but those pressures dont sound good

good luck

RellikZephyr

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GTR032 Experienced

GTR032

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I just had mine comp tested at Grey imports here in sydney. 190 highest and 180 lowest..maybe gauge was reading high? But still pretty even which is a good sign, nathan there said, no need for a leak down test, its pretty good.

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The Dan Grand Master

The Dan

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after I rebuilt my gtst - which is practically the same so be quiet all you GTR owners - I had a reading of 120 140 130 160 80 120 when it was cold and a reading of 160 160 160 160 160 160 when it was warm.

This is how much of a difference it will make so get it checked when it is at operating temp.

I also have forged pistons so be quiet all you cast piston owners....lol

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