I think I screwed up
Thread Starter
|
Professional
Joined: Oct 2010
Posts: 160
Likes: 0
From: austin texas
I think I screwed up
Well when I did the head gasket job on my truck. when I put the rockers back on instead of putting the timing on the v8 mark at 147 past TDC I torqued them down @ TDC could this be holding my valve open now im getting a # 4 misfire and only a 55 with leaking down to 0 on a compression test. just wondering
Legend
Joined: Jul 2007
Posts: 7,843
Likes: 13
From: DFW, Texas
Only a major problem if you have adjustable rocker arms. Stock rocker arms will compress the spring at the correct lifter preload.
The biggest thing to watch with non adjustable rocker arms is torquing down the valve that has max lift on one valve but not the other. You'll know that when one pushrod is about a half inch higher than the other. It they are attached as pairs, you need to make sure the highest one gets tightened first, otherwise one will get bent up or snap.
The biggest thing to watch with non adjustable rocker arms is torquing down the valve that has max lift on one valve but not the other. You'll know that when one pushrod is about a half inch higher than the other. It they are attached as pairs, you need to make sure the highest one gets tightened first, otherwise one will get bent up or snap.
Legend
Joined: Jul 2007
Posts: 7,843
Likes: 13
From: DFW, Texas
the absolute safest way is as such:
Rotate the engine until the cam is on the base circle (no lift) of the cylinder in question. Tighten the rocker arm down to 21 ft lbs. For non-adjustable and stock rocker arms that's all there is.
If using adjustables, tighten the adjuster nut down to zero lash, that is the point where the up and down movement of the pushrod just stops, meaning there is no play up and down between the pushrod and the lifter or rocker arm cups. If you are ****, you can put a dial indicator on the spring retainer and find the exact spot where the dial indicator changes, signifying that you are transferring lift to the spring. After you find that spot, tighten 1/2 to 3/4 turn more to set lifter preload. Then rotate the engine and do the next cylinder.
Mopar has a chart to help you from needlessly turning the engine over and over again to find the base circle:
http://www.mopar1.us/valvelash.jpg
After you have adjusted the rocker arms, start the engine and idle. If the ticking sound doesn't go away in 3-5 minutes, go back in and tighten the rocker arm adjuster another 1/4 turn. If you overdo it, you will transfer lift to the valve and it will stay open.
Rotate the engine until the cam is on the base circle (no lift) of the cylinder in question. Tighten the rocker arm down to 21 ft lbs. For non-adjustable and stock rocker arms that's all there is.
If using adjustables, tighten the adjuster nut down to zero lash, that is the point where the up and down movement of the pushrod just stops, meaning there is no play up and down between the pushrod and the lifter or rocker arm cups. If you are ****, you can put a dial indicator on the spring retainer and find the exact spot where the dial indicator changes, signifying that you are transferring lift to the spring. After you find that spot, tighten 1/2 to 3/4 turn more to set lifter preload. Then rotate the engine and do the next cylinder.
Mopar has a chart to help you from needlessly turning the engine over and over again to find the base circle:
http://www.mopar1.us/valvelash.jpg
After you have adjusted the rocker arms, start the engine and idle. If the ticking sound doesn't go away in 3-5 minutes, go back in and tighten the rocker arm adjuster another 1/4 turn. If you overdo it, you will transfer lift to the valve and it will stay open.
Last edited by aim4squirrels; Jul 27, 2011 at 04:28 PM.