85 L98 Compression Reading
Thread Starter
Racer
Joined: Oct 2004
Posts: 278
Likes: 23
From: Rock Hill, SC [RCG] KANUCK
85 L98 Compression Reading
Hello
am wondering if someone could tell me what the compression should be on an 85 L98, mine is around 160 in most cylinders except for 2, which are around 175, ws wondering if maybe I have some carbon build up in these cylinders.
Thanks
am wondering if someone could tell me what the compression should be on an 85 L98, mine is around 160 in most cylinders except for 2, which are around 175, ws wondering if maybe I have some carbon build up in these cylinders.
Thanks
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Those two could be higher or the other six lower than when new.
Squirt a little motor oil into each cylinder and see if the others come up, if so it's ring wear; if not, it could be worn valve seats in the other cylinders.
Do the two higher cylinders pump up faster than the others?
Squirt a little motor oil into each cylinder and see if the others come up, if so it's ring wear; if not, it could be worn valve seats in the other cylinders.
Do the two higher cylinders pump up faster than the others?
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Was the engine warm? And were the high ones the first you measured or....? How many cranks it takes to reach the pressure is very important, take note of the approx pressure after each rotation, it should make it there on the 3rd or 4th turn.
Those numbers sound good btw. I got 180-190, but that was on a hot engine, and everyone elses numbers are close to yours.
Those numbers sound good btw. I got 180-190, but that was on a hot engine, and everyone elses numbers are close to yours.
Racer
Joined: Sep 2004
Posts: 495
Likes: 0
From: berwick pennsylvania
compression
Originally Posted by CentralCoaster
Was the engine warm? And were the high ones the first you measured or....? How many cranks it takes to reach the pressure is very important, take note of the approx pressure after each rotation, it should make it there on the 3rd or 4th turn.
Those numbers sound good btw. I got 180-190, but that was on a hot engine, and everyone elses numbers are close to yours.
Those numbers sound good btw. I got 180-190, but that was on a hot engine, and everyone elses numbers are close to yours.
got new heads to take care of that
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by selkirk24
Hello
am wondering if someone could tell me what the compression should be on an 85 L98, mine is around 160 in most cylinders except for 2, which are around 175, ws wondering if maybe I have some carbon build up in these cylinders.
Thanks
am wondering if someone could tell me what the compression should be on an 85 L98, mine is around 160 in most cylinders except for 2, which are around 175, ws wondering if maybe I have some carbon build up in these cylinders.
Thanks
RACE ON!!!
