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tb13
11-19-2017, 02:12 PM
I recently ripped apart a built SR20 I bought a while back. The #1 rod journal looks concerning, one side looks pretty normal where as the other side looks entirely different. The bearing was not spun, but it was worn which I understand because the engine was built over 6 years ago. Is this crank worth taking to the machine shop to have inspected and polished or should I just use the other crank I have?

https://i.imgur.com/ytFKucWh.jpg
https://i.imgur.com/MBLfMcth.jpg
https://i.imgur.com/fjgk8Qyh.jpg
https://i.imgur.com/TbNpmzAh.jpg
kyral
11-19-2017, 02:41 PM
Anything a fingernail can catch on?
RalliartRsX
11-19-2017, 02:45 PM
Drop it off at the machine shop. If you can feel it with a finger nail, it may be best grabbing anorter crank.

Mine looked similar and the machine shop was able to polish it out. It's out getting measured for bearings as I type this
tb13
11-19-2017, 02:56 PM
Anything a fingernail can catch on?

Drop it off at the machine shop. If you can feel it with a finger nail, it may be best grabbing anorter crank.

Mine looked similar and the machine shop was able to polish it out. It's out getting measured for bearings as I type this

Fingernail doesn't catch anything which is what makes me think it should be okay. I was mainly concerned with how it looks, but if this seems like something that can be polished out I'll probably take both to be inspected and polished and if both are good to go, the second will go in a cabinet to chill until I need it.
hanzbrady
11-19-2017, 03:01 PM
Get the crank polished and those rods re-sized. Notice how the wear is more aparent on the top and bottom of the bearing? That happens when you over-torque a rod and oval the rod journal.
tb13
11-19-2017, 03:03 PM
Get the crank polished and those rods re-sized. Notice how the wear is more aparent on the top and bottom of the bearing? That happens when you over-torque a rod and oval the rod journal.

Wasn't me that did it lol, but I see what you mean. Rods will be looked over before they go back in for sure, I was surprised when I disassembled it how tight the bolts were.
hanzbrady
11-19-2017, 03:05 PM
Wasn't me that did it lol, but I see what you mean. Rods will be looked over before they go back in for sure, I was surprised when I disassembled it how tight the bolts were.

No worries, it happens a lot when people just torque rods by torque spec and not with a rod bolt stretch gauge.

Think of the torque rating as a generally safe guideline, the rod bolt stretch gauge is an absolute science.
tb13
11-19-2017, 03:15 PM
No worries, it happens a lot when people just torque rods by torque spec and not with a rod bolt stretch gauge.

Think of the torque rating as a generally safe guideline, the rod bolt stretch gauge is an absolute science.

They are eagle rods so not the highest quality to begin with, but the motor has a fully balanced rotating assembly so I'd like to keep them if I can along with the crank in question.

Judging by some of the things I found disassembling the engine, it doesn't surprise me the bolts were over torqued :ugh: