Crankshaft balancing pros and cons

[DriftNinjah]

Doing a full rebuild on my SR20DET with a spun bearing. I'm obviously going to need to resurface the crankshaft. That will cost $110 at the machine shop I'm going to, they will also balance it for another $150.

I'm just wondering if you all think I should do that or not and if so why? Whats the advantages? I have a basic understanding of what it would do, but is it really going to be worth the extra cash?

Random side info that might make a difference: Its an all stock motor that's getting a full Cometic gasket set, new ACL race main and rod bearings, and OEM rings.

[Edwin562]

if the spun bearing chewed up metal from the crank, obviously its out of balance because out of factory they are balanced.

[Frank_Jaeger]

Spend the extra money and get it balanced. Or find a stock crank in good spec.

[Walperstyle]

Spend the extra money and get it balanced. Or find a stock crank in good spec.

Be careful what you say when giving advice. A stock crank wouldn't necessarly just 'drop in' a different block. I do realize you said in 'good spec'. Elaborate that the OP should check fillet roll, ID vs OD of the block (with bearings).

From doing this first hand, its actually easier and more cost effective to give a block to a machine shop, with a crank and say 'order me some bearings that fit within xxx spec'. Then, the machine shop will micro polish and balance the crank specific to your engine.

I personally purchased bearings, installed them in myself, checked all my clerances, only to realize I needed to send my block back to the machine shop to get the crank polished to fit. aka, I could have saved about $200 if I did it right the first time.

Engines that come out of a factory are not all 100% the same. ...even more so when you are dealing with cams and cam caps.
..i made the mistake of buying a head without cam caps. That was another waste.

[Om1kron]

cheap out on an engine build, blow rebuilt engine 300 miles later if you're lucky and spend a few grand getting a completely different motor without all of your goodies in it. Lesson learned.

[DriftNinjah]

So I have the crankshaft pulled out and its bad. Cylinder 4 position had spun the bearing and its been eaten pretty good and the tab from the bearing is stuck in the groove. So my question is will the 93 SE-R sr20de crank fit my 93 180sx sr20det redtop? It would be around $150 cheaper to go this route, but even more importantly I don't think I'm within the proper tolerances for how small my current crank could be machined(quite a bit was eaten down). Will it fit and if so what do I loose by going with the DE crank?