Johnson 5,5 compression

[MOTION LINE]

What is the right compression for a 5,5 from year 1957?<br /><br />The reading is now 65 PSI or 4,5 kg/m3!

 

[JB]

Re: Johnson 5,5 compression

PSI will vary a lot from different guages and techniques, ML.<br /><br />On that engine one might get numbers as low as 60psi or as high as 125psi, both on a healthy engine.<br /><br />The important number is the difference between the two cylinders when measured in exactly the same way. They should not differ more than 15%.