Forums
New posts
Search forums
Image search
Shop
Amazon Store
T-Shirts
Stickers
Members
Current visitors
Supporting Member Upgrade
Sponsors
About
Log in
Register
Search
Search titles only
By:
Search titles only
By:
New posts
Search forums
Image search
Search
Search titles only
By:
Search titles only
By:
Menu
Install the app
Install
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Forums
Jeep Wrangler YJ
YJ General Discussion
New Cam, Timing Chain & Head. #1 No Compression
Reply to thread
Message
<blockquote data-quote="Gilaguy23" data-source="post: 429505" data-attributes="member: 19498"><p>The harmonic balancer should have a nice visible line on it to indicate TDC. That lines up with the timing cover tab or casting where it shows degrees of timing. I can say have heard of the outer ring slipping a bit on the inner part which would cause bad timing marks basically but its pretty uncommon.. Keep in mind there are 2 TDC's on a 4 stroke engine. One TDC setting is where #1 piston is top dead on the compression stroke. If you rotate the engine by the crank 1360 degree revolution you now align the balancer mark to TDC again but have it somewhere in either the intake, exhaust stroke or valve overlap. Probably would take 2 people but If you pull the plugs and stick your finger over cyl #1 plug hole you'll feel the compression building. Once it hits the timing marks as it builds you know its on the compression stroke. </p><p> But...If I understand you correctly after it was tore down and reassembled you ran a comp test and had 0 in #1. That would indicate deeper troubles as you note. Going back here if you pulled the valve cover and rotated the engine by hand by the crank bolt aligning the TDC points twice ,one of them should give you completely closed valves on #1,compression stroke. Being the cam may be off you might find at no time when those marks are aligned the valves are fully closed,but one or both are being held open slightly. Then in fact you have cam alignment issues and it needs to be torn into again. Hope this all makes sense.</p></blockquote><p></p>
[QUOTE="Gilaguy23, post: 429505, member: 19498"] The harmonic balancer should have a nice visible line on it to indicate TDC. That lines up with the timing cover tab or casting where it shows degrees of timing. I can say have heard of the outer ring slipping a bit on the inner part which would cause bad timing marks basically but its pretty uncommon.. Keep in mind there are 2 TDC's on a 4 stroke engine. One TDC setting is where #1 piston is top dead on the compression stroke. If you rotate the engine by the crank 1360 degree revolution you now align the balancer mark to TDC again but have it somewhere in either the intake, exhaust stroke or valve overlap. Probably would take 2 people but If you pull the plugs and stick your finger over cyl #1 plug hole you'll feel the compression building. Once it hits the timing marks as it builds you know its on the compression stroke. But...If I understand you correctly after it was tore down and reassembled you ran a comp test and had 0 in #1. That would indicate deeper troubles as you note. Going back here if you pulled the valve cover and rotated the engine by hand by the crank bolt aligning the TDC points twice ,one of them should give you completely closed valves on #1,compression stroke. Being the cam may be off you might find at no time when those marks are aligned the valves are fully closed,but one or both are being held open slightly. Then in fact you have cam alignment issues and it needs to be torn into again. Hope this all makes sense. [/QUOTE]
Verification
Post reply
Forums
Jeep Wrangler YJ
YJ General Discussion
New Cam, Timing Chain & Head. #1 No Compression
Top
Bottom