Bad Rings?
Thread Starter
Instructor
Joined: Mar 2009
Posts: 225
Likes: 1
From: Dripping Springs TX
Bad Rings?
So I have an '01 Z06 with an ERL 427. I took the car in a couple weeks ago for a new tune, and long story short, #3 Exhaust spring was broken. New Lunati Gold Dual Valve Springs were installed. Downsized my 80# injectors to Fast 60# and added Hallteck Kikller Bee II intake. Commence Dyno tuning... The car was starting to make good numbers, wound up at 540/535. There was a lot of grey, oil smelling smoke billowing out above 3500 RPM all the way up. Oil residue on the exhaust tips as well. Did a compression check and all cylinders were 135-145#. Engine is supposed to be 11.5:1 No leakdown tester was on hand, but is on it's way. One run was done with the oil cap off and it billowed like a smoke stack. Was told I needed new rings. Before I bite the bullet on this, does this sound to be the culprit? The leakdown should be done in a couple days. Here's hoping there is a simpler solution....
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
See what the leak down tester says. See LOTS of engines with the intake manifolds full of PCV blow by oil. Do you have a catch can??
Please let us know what the leak down tester says.
Bill
Please let us know what the leak down tester says.
Bill
Le Mans Master
Joined: Jul 2010
Posts: 5,954
Likes: 711
So I have an '01 Z06 with an ERL 427. I took the car in a couple weeks ago for a new tune, and long story short, #3 Exhaust spring was broken. New Lunati Gold Dual Valve Springs were installed. Downsized my 80# injectors to Fast 60# and added Hallteck Kikller Bee II intake. Commence Dyno tuning... The car was starting to make good numbers, wound up at 540/535. There was a lot of grey, oil smelling smoke billowing out above 3500 RPM all the way up. Oil residue on the exhaust tips as well. Did a compression check and all cylinders were 135-145#. Engine is supposed to be 11.5:1 No leakdown tester was on hand, but is on it's way. One run was done with the oil cap off and it billowed like a smoke stack. Was told I needed new rings. Before I bite the bullet on this, does this sound to be the culprit? The leakdown should be done in a couple days. Here's hoping there is a simpler solution....
Last edited by helga203; Jul 17, 2012 at 08:40 PM.
Race Director
Joined: Jan 2008
Posts: 16,027
Likes: 169
From: oregon
let me share something about compression tests. one of my side hobbies is autocrossing FWD. one of my engines started using a lot of oil and i figured it needed a rebuild. it should of had 250-260psi of compression. it was showing 180 on the gauge in 3 holes and 100psi in the down cylinder. i sell the whole engine and just import another low mileage one to burn up. compression test the new engine. it's showing 180 in all 4. i freak, call the place screaming....then it dawns on me, i wonder if this gauge is wrong? i unscrew the tube i was using since these DOHC engines have deep spark plug tubes, just put the hose in the hole, screw it down best i can, crank it. boom, 260psi. it then dawns on me my older engine i sold for less than i should have at most needed a new piston and rings in one cylinder. it was not worn out and my compression gauge cost me about $1000
moral of the story: those "helper tubes" you put on compression gauges mess with the numbers and always use a quality gauge, keep 2 on hand if you can to check against each other.
moral of the story: those "helper tubes" you put on compression gauges mess with the numbers and always use a quality gauge, keep 2 on hand if you can to check against each other.
