GTL Compression

[Simon Knight]

HI all, i have just done a compression test on my GTL and all four cylinders were around 12 bar. I`m happy they are all roughly equal but can someone tell me what the pressure should be please?

Cheers Simon.

 

[mr-reno-139]

in old money 150 psi is normal

 

[Simon Knight]

Thanks Paul.

Cheers Simon.

 

[Jnr-Renospeed]

HI all, i have just done a compression test on my GTL and all four cylinders were around 12 bar. I`m happy they are all roughly equal but can someone tell me what the pressure should be please?

Cheers Simon.

12 bar equates to 174psi which is an 11.8:1 compression ratio.

Like Paul says it should be about 140-150psi, so I suspect that your gauge is not reading correctly.

 

[Simon Knight]

Hi Jr-Renospeed, thanks for the reply, the gauge was cheap on Ebay so I quess I need a better quality one. All cylinders were equal so I'm happy for now. The car is running fine I was just checking out of interest.

Cheers Simon.

 

[angel]

12 bar equates to 174psi which is an 11.8:1 compression ratio.

Like Paul says it should be about 140-150psi, so I suspect that your gauge is not reading correctly.

Geometrical compression ratio has very little to do with compression pressure readings, there are a lot of factors who affect actual readings like cam overlap duration, closing point of inlet valve etc. You will be amazed to see how much compression pressure can rise after, say, adjusting correctly rocker arm clearances that are only 5 thou too tight.

For start, 12 bars is an excellent reading, I would not be too much concerned if it actually was 10 or 9 or 13 bars - what matters is that there is little variation among cylinders.

 

[Simon Knight]

Hi Angel, thanks for the info i`ts much appreciated, As you say i`m happy all four cylinders are roughly equal.

Cheers Simon.

 

[AdamWilkes]

Like angel said; it's amazing also how much better the engine can run when tappet clearances are adjusted correctly!