help on cylinder leak down test
Thread Starter
Teching In
Joined: Feb 2004
Posts: 49
Likes: 0
help on cylinder leak down test Doing a little make over on my 2000 SS. I am doing a leak down. How long should it take for 100 psi dry air to leak out of a cylinder? 
please help! When I brought it down I thought I had scorched some valves and they were a little pitted. Just added heads, 232-238 , 114 cam, new tranny with all the goodies, 3600 stall, long tubes and 4.10s. I sure would hate to tear it back down. 
By the way I do all my own work so labor is at least free. 
please help! When I brought it down I thought I had scorched some valves and they were a little pitted. Just added heads, 232-238 , 114 cam, new tranny with all the goodies, 3600 stall, long tubes and 4.10s. I sure would hate to tear it back down. By the way I do all my own work so labor is at least free. Thread Starter
Teching In
Joined: Feb 2004
Posts: 49
Likes: 0
leak down
Originally Posted by derek_silvy
This does not help you... and I hate to get off topic, but how do you go about a cylinder leakdown test?
TECH Regular
Joined: Sep 2004
Posts: 404
Likes: 0
From: Raleigh, NC
Well first off, you should try doing a leak down test the RIGHT WAY. Go buy/borrow a cylinder leak down tester!! With the correct tool you will only supply about 35-40 pounds of air into the cylinder. Up to 60% leakage is acceptable. Less than 40% is good. 100 pounds of air is most deffinately going to leak somewhere fairly quick, even in a good engine (rings would be the easiest place to leak). I do not see how your method of using a compression guage tells you much of anything. You need the right tool.
Thread Starter
Teching In
Joined: Feb 2004
Posts: 49
Likes: 0
Found the solution to the problem. Took my setup to a buddys 99 SS. Knew his blow by was minimal because of a rebuild and compression test. Hooked him up and it took his 13 seconds to drop to zero. Mine took 15 seconds so I know I'm OK 
. thanx God 
! By the way CSTICK is absolutly right. It would have been much easier with the proper tools but I didn't have the right tools and my current expenditures have left my reserves at an all time loooow. got to save enough for a dyno tune and a trip to the track. Thanx for the imput.
. thanx God ! By the way CSTICK is absolutly right. It would have been much easier with the proper tools but I didn't have the right tools and my current expenditures have left my reserves at an all time loooow. got to save enough for a dyno tune and a trip to the track. Thanx for the imput. Trending Topics
I just filled the cyl. to 90psi and turned the engine until both valves were closed.Theres a fine line between open/closed but after doing it u kinda know where your at when u hit tdc or just before it.
I had less than 3% in every hole both hot and cold.The only thing I wish I wouldve done is go forged pistons.The stockers rock (Hypers) until there warm but ring seal is awesome in my motor.
I had less than 3% in every hole both hot and cold.The only thing I wish I wouldve done is go forged pistons.The stockers rock (Hypers) until there warm but ring seal is awesome in my motor.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Originally Posted by jazzz007
Found the solution to the problem. Took my setup to a buddys 99 SS. Knew his blow by was minimal because of a rebuild and compression test. Hooked him up and it took his 13 seconds to drop to zero. Mine took 15 seconds so I know I'm OK . thanx God ! By the way CSTICK is absolutly right. It would have been much easier with the proper tools but I didn't have the right tools and my current expenditures have left my reserves at an all time loooow. got to save enough for a dyno tune and a trip to the track. Thanx for the imput.
. thanx God ! By the way CSTICK is absolutly right. It would have been much easier with the proper tools but I didn't have the right tools and my current expenditures have left my reserves at an all time loooow. got to save enough for a dyno tune and a trip to the track. Thanx for the imput.David
