Crankshaft Inspection

[biggercb]

What do you guys look for when inspecting a crankshaft? I came across a spare bottom end and I want to determine whether to split the cases or just slap a jug on it and use it.

Thanks!

 

[JonS]

look for side to side play and up and down play. measure to check the specs of it and compare them with factory tolerances.

 

[sicivicdude]

If you download the factory service manual from the general support section and go to page 2-4 to the general specifications, it has the crankshaft specs at the bottom of the page.

The really important ones are big end side clearance (how far the rod slides side to side on the crank) which is supposed to be between .016" -.028" and big end radial clearance (how far the rod is allowed to move "up and down") which is supposed to be between .0008" and .0014" (which is basically immeasurable)

 

[biggercb]

Sounds good, thanks again!

 

[sicivicdude]

But, as my dad used to say: When in doubt, pull out!

If something in there is not giving you "the warm and fuzzies" you'd be better to split the cases and check it all out thoroughly. Crank bearings are easier to put in if all you have to do is split the cases, much more difficult to do once they've flown apart and busted the engine into a million pieces....

 

[Blaner]

the purple heat treatment is normal that is from the factory when they assembled the crank.