5efte compression
- Thread starter Naldo250
- Start date
gorganl2000
Lifer
with dished forged pistons ...my compression on a freshly built 5efte was about 170psi per cylinder.
that was 7 years ago, i've not done another compression test since
prior to that, with the shaved 4efte pistons, it was around 160psi per cylinder iirc
the typical 5efte compression is between 150 - 190 per cylinder with CR maybe between 8.7 - 9.1
was your car put down for a while (stuck ring maybe??)
90 is very low and may be why you're experiencing blow by....though it seems strange its on all the cylinders
that head gasket is half the thickness to the oem 4efte headgasket....so that may have raised your CR, which can increase the potential for detonation and ring land damage.
based on what you listed, i'd guess a CR of 9.6/9.8 and cylinder compression in the range 180 - 220,, which again is comparatively high
that was 7 years ago, i've not done another compression test since
prior to that, with the shaved 4efte pistons, it was around 160psi per cylinder iirc
the typical 5efte compression is between 150 - 190 per cylinder with CR maybe between 8.7 - 9.1
was your car put down for a while (stuck ring maybe??)
90 is very low and may be why you're experiencing blow by....though it seems strange its on all the cylinders
that head gasket is half the thickness to the oem 4efte headgasket....so that may have raised your CR, which can increase the potential for detonation and ring land damage.
based on what you listed, i'd guess a CR of 9.6/9.8 and cylinder compression in the range 180 - 220,, which again is comparatively high
Last edited:
dac69er
Super Moderator
If you have blowby on a fresh engine and you don't have excessive piston slap all the time it's most likely your ring gaps are too loose.
You may have also glazed your cylinders so you aren't getting a very good seal.
Does adding oil down the plug holes and trying the compression test again help the reading or makes no difference?
Is the compression the same across all 4 cylinders?
You may have also glazed your cylinders so you aren't getting a very good seal.
Does adding oil down the plug holes and trying the compression test again help the reading or makes no difference?
Is the compression the same across all 4 cylinders?
thank you very much for the info
turns out the blockk was wore
yes im glazed the cylinder walls with a hoaner
gorganl2000
Lifer
depending on how bad it is, may be inquire about a rebore with a bigger sized piston
hello guys another quick question.
im getting oil in cylinder 1 and 3
since i used the metal gasket im noticing that dont know if is becuase im not using headstuds maybe
i torque the head down to 70ft lbs and still getting oil in the cylinders
i notice right around the cylinder there is a sweat of oil so i dont know if that could be the issue
the car idles rough before of that but as i crosses 2000 - 2500 rpm its runs smoothly
im getting oil in cylinder 1 and 3
since i used the metal gasket im noticing that dont know if is becuase im not using headstuds maybe
i torque the head down to 70ft lbs and still getting oil in the cylinders
i notice right around the cylinder there is a sweat of oil so i dont know if that could be the issue
the car idles rough before of that but as i crosses 2000 - 2500 rpm its runs smoothly