Hi can somebody let us know what kind of compression readings/results we should be getting from a 4x4 saph with around 106k (not too sure if its been rebuilt but know the top end has been done @90k)

On a dry test we got the following results:

Cyl 1: 160 psi
Cyl 2: 135-140 psi
Cyl 3: 140 psi
Cyl 4: 150-160 psi

On a wet test (dropping some oil into each bore/spark plug hole)

Cyl 1: 160 psi
Cyl 2: 145-150 psi
Cyl 3: 150 psi
Cyl 4: 160 psi

Car starts & drives fine no overheating, losing/mixing water etc...

The reason the test was done because it seems to give out blue'ish smoke now and then. When the spark plugs were removed for the test no. 4 plug was covered in Oil, is this normal?

Any input appreciated

 

im not sure but you might have oil getting past the rings or it might be worn valve guides /stem rubbers

marco

 

sounds like just general wear and tear on the rings particuarly on the middle two cylinders.

Exactly the sort of engine that keeps going forever at standard power, but dies very quicky at stage 3 IMHO!

 

Thought as long as they are all within 10% of each other its ok?

 

Forgot to add its a Stage 3 and what do you mean by it'll die what will happen like will it just sieze up or something?

 

Depends on what you mean by "ok"?

It will run, yes.

 

Nope, they NEVER seize in my experience, they just get smokier and smokier and slower and slower until you feel you have to eventually do something about it!

Dramatic failures almost never happen on an old YB if they are given regular oil changes and belt changes and pump changes etc, nothing that loose is EVER going to seize, lol

 

Any idea why i have oil in no.4 spark plug area?

 

If they were all 1psi they'd be within 10% of each other So thats that theory fucked then

 

Good point, well made

 

if you knew my old saff you'd take that back

mine smoked as std spec ar 93k, at 100 it was stage 1, then 110k stage 3

348 and 14000miles later still goign strong, still smoking on hard throttle,

then i smashed it up

the engine is now going in a puma


but general you are right

 

if the spark plug was covered in oil, somthing isnt quite right, but the test dis-proves massively worn rings.

Maybe whip the head off for a look if you;re that concerned?