Ok heres the deal. We rebuilt a B18c1 about 6 months ago. It boggled us that the compression was only 175.
Now were are messing with the same motor. We added some upgrades, AND put new rings in AGAIN. And the compression is at 160??

Heres the specs
Cylinder bore 81.5 mm (+.003)
pistons 81.5mm
end gap on rings

Am I missing something? How the hell can this happen??? TWICE?

 

how about the valves. are they seating correctly?
no scratches in the cylinder wall are there?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bay Area Baller &raquo;</TD></TR><TR><TD CLASS="quote">Ok heres the deal. We rebuilt a B18c1 about 6 months ago. It boggled us that the compression was only 175.
Now were are messing with the same motor. We added some upgrades, AND put new rings in AGAIN. And the compression is at 160??

Heres the specs
Cylinder bore 81.5 mm (+.003)
pistons 81.5mm
end gap on rings

Am I missing something? How the hell can this happen??? TWICE?

</TD></TR></TABLE>


how many miles on the motor?

 

cold motor? cranks number of times? ran it for the rings to sit?

 

What mod did you do to it? since you are stating you changed something up in the motor. Also psi in a cylinder is not always a bad thing. If they are all even it's should be fine. Now if you changed something that will change the static compression of the motor but all psi in each cylinder corresponds with all other's I dont see a problem ( then again there is not much to go on in the above mentioned post)

Give us more info, since I hate being a e-mechanic

 

was the throttle wide open?

 

How was the compression test done? did you remember to disable the fuel system?