Sparkplug Install
Posted by Bob J On 2024/4/23 14:00:25
Embarrassing admission:
Ran into an issue I have not ever experienced before. Had bad missing occurring in the engine and got her running long enough to get the hood open. There was blow-by coming out and around of a number of sparkplugs! I had not tightened the plugs in tight enough!
With the blow-by carbon also reduced the ground and fouled the plug further. I took them all out, cleaned them up, then replaced them doing the final tightening with a torque wrench. All good now.
As an experiment I tightened them to what I felt was 30 ft/lbs on the socket wrench (25-35 ft/lb spec range on a 14mm plug) and found that I was actually around 20 ft/lbs. I expect the metal ring gasket is what fooled me, it took a few arcs of the torque wrench to crush that seal down and start gaining torque. I am always afraid of over-tightening as you can change the gap and worse, break the porcelain (I think the lower torque let them loosen themselves out after a bit of driving, as there was no issue upon first driving the fresh re-build.)
Just thought I would share to help those also not as used to these style plugs.
Bob J.
Attach file:
sparkplugs.JPG (141.75 KB)
Ran into an issue I have not ever experienced before. Had bad missing occurring in the engine and got her running long enough to get the hood open. There was blow-by coming out and around of a number of sparkplugs! I had not tightened the plugs in tight enough!
With the blow-by carbon also reduced the ground and fouled the plug further. I took them all out, cleaned them up, then replaced them doing the final tightening with a torque wrench. All good now.
As an experiment I tightened them to what I felt was 30 ft/lbs on the socket wrench (25-35 ft/lb spec range on a 14mm plug) and found that I was actually around 20 ft/lbs. I expect the metal ring gasket is what fooled me, it took a few arcs of the torque wrench to crush that seal down and start gaining torque. I am always afraid of over-tightening as you can change the gap and worse, break the porcelain (I think the lower torque let them loosen themselves out after a bit of driving, as there was no issue upon first driving the fresh re-build.)
Just thought I would share to help those also not as used to these style plugs.
Bob J.
Attach file:
sparkplugs.JPG (141.75 KB)This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=270629