The importance of paying attention while engine building.
04-01-2013, 06:26 PM
#1
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The importance of paying attention while engine building. I know im new here but what I just discovered Im sure can be applied to anyone assembling an engine. I am in the process of rebuilding my LQ9 to put into my 240sx. Complete refresh, new oem rods, pistons, rings, bearings, ground and polished crank etc etc. This is also my first LS assembly, having put nissan motors together prior. Getting to the specifics, assembly of the crank/pistons/rods went rather easy. Having the factory service manual out makes it almost fool proof. However what I found tonight, human error always can mess things up!
One of the OEM rods I recieved had a bad wrist pin bushing so I only assembled 7 of the 8 piston/rods into the motor and it sat while I was waiting on the replacement to be delivered. Something however was nagging me that I felt like I had missed final torquing with the angle gauge on one of the rods. It has been in the back of mind the entire week that I should really check each bolt and make sure everything was good. Got the new rod in over the weekend and finally got to putting it in tonight. Cleaning, lubed, installed etc everything good. I figured while its still open I NEED to check everything. So I set my torque wrench to 45ft-lbs. Figured if each bolt reacted the same way to this setting, breaking immediately with no movement that bolt was good. Started at the back and went rod to rod even checking the one I just did. Turns out I missed one rod and not only one bolt BOTH bolts! Unbolted the cap, and re-torqued per the FSM and rechecked just as I did all the others good to go.
Decided I might as well check the main caps too since I was in that mindset. Turns out I MISSED one outer bolt on #4 main. Got everything to spec and told my wife about the importance of paying attention, look I checked my work so it wont come apart, got the stank eye look like "ill sell that POS car if you break it" etc.
Trying to figure out what went wrong, led me to my camera to check my photos that I took during the build and thats when it hit me. I took two photos of the angle gauge on the motor. Both photos were the rod and main that were not final torqued! This was the first time I ever took photos of a rebuild and it will be my last! I know its a long story but I know there's a bunch of me's out there excited to build a block and document it, but I cant stress the pay attention and not getting distracted part because if I didnt keep thinking about missing something my motor would have come apart immediately and all that money down the drain.
One of the OEM rods I recieved had a bad wrist pin bushing so I only assembled 7 of the 8 piston/rods into the motor and it sat while I was waiting on the replacement to be delivered. Something however was nagging me that I felt like I had missed final torquing with the angle gauge on one of the rods. It has been in the back of mind the entire week that I should really check each bolt and make sure everything was good. Got the new rod in over the weekend and finally got to putting it in tonight. Cleaning, lubed, installed etc everything good. I figured while its still open I NEED to check everything. So I set my torque wrench to 45ft-lbs. Figured if each bolt reacted the same way to this setting, breaking immediately with no movement that bolt was good. Started at the back and went rod to rod even checking the one I just did. Turns out I missed one rod and not only one bolt BOTH bolts! Unbolted the cap, and re-torqued per the FSM and rechecked just as I did all the others good to go.
Decided I might as well check the main caps too since I was in that mindset. Turns out I MISSED one outer bolt on #4 main. Got everything to spec and told my wife about the importance of paying attention, look I checked my work so it wont come apart, got the stank eye look like "ill sell that POS car if you break it" etc.
Trying to figure out what went wrong, led me to my camera to check my photos that I took during the build and thats when it hit me. I took two photos of the angle gauge on the motor. Both photos were the rod and main that were not final torqued! This was the first time I ever took photos of a rebuild and it will be my last! I know its a long story but I know there's a bunch of me's out there excited to build a block and document it, but I cant stress the pay attention and not getting distracted part because if I didnt keep thinking about missing something my motor would have come apart immediately and all that money down the drain.
04-01-2013, 07:03 PM
#4
Exactly why I always use a yellow parts marking pen. Torqued.. It gets a dot of yellow paint....
I always use an assembly record sheet, too. As each is torqued, marked, the sheet is checked off.
I did have a BAD deal on my alky rail engine,,,Due to bull$hitting while putting the wrist pin locks in!
Current RULE: If someone shows up, the engine gets covered up, til they leave.
I always use an assembly record sheet, too. As each is torqued, marked, the sheet is checked off.
I did have a BAD deal on my alky rail engine,,,Due to bull$hitting while putting the wrist pin locks in!
Current RULE: If someone shows up, the engine gets covered up, til they leave.
04-01-2013, 07:44 PM
#6
I just finished mine working solo in a sorta busy shop with other projects happening. Distractions are a part of life, but check, recheck, and final checks are sure good for piece of mind. I feel very confident in my current build and seeing it on the stand is a real piece of satisfaction. Hammering it down the track will be another.
