oxblood!z28

Sory I placed this in the newb section earlier.....
Whats up you guys I had a question in regards to replacing a stock crank. I was wondering if it needed to be balanced if I replaced just the crank. It is going to be a stock replacement for my 2000 z28 and the pistons and rods are staying in. I'm under the impression that when you replace the crank you need to balance it to the lightest rod and piston. Is this needed if it is just a stock replacement.

bww3588

iTrader: (49)

Depends on what it came out of...5.3 ls1 and 6.0 cranks have the same part number but are balanced differently.

Most factory cranks are off balance by a little bit as they are all balanced the same. They aren't balanced to the exact pistonp and rods that are going in that particular engine, which could be heavier or lighter than other pistonp. If everything is stock and you have a crank that came out of an ls1, I wouldn't worry about it.

Sales3@Texas-Speed

iTrader: (2)

Like stated, if this is just a stock rebuild, then it should work fine. Balancing will only make it work more efficient.

oxblood!z28

Man now I'm confused I posted this on the newb section by accident and their saying balance it but i get it now only if i want it more efficient. It's going to be a stock ls1 replacement crank from another ls1. I suppose replacing the crank is better than tapping the snout of the crank(bolt broke off the in the crank). I'm sure some would say tapp the snout and leave it at that but what are the cons of doing that?

ls1fst98

iTrader: (3)

get an easy out kit...that may work and its like 20$. or if you do a stock ls1 crank with stock ls1 pistons and rods, you do not need to do a balance on it. its an option but not required. built a few of these with stock internals and have yet to balance any. now if you went with an aftermarket crank or stock crank and aftr market pistons and rods, then yes have it balanced. but no you do not need to have the rotating assembly balanced for stock stuff.

oxblood!z28

I tried an easy out kit it didn't work for me. I know people have had luck with it but i'm not one of them. I wish though.
@Jake i was wondering what you ment by being more efficient if I got it balanced.
Do you guys know the cons of tapping the snout of the crank to fit a new crank bolt. It was mentioned to me before, and its a seems ok to do in my head but what problems would you run into down the road in real life?

bww3588

iTrader: (49)

same principal as balancing your tires, close will work, but perfect is better.

less vibrations, more reliability. in turn, more efficient.

however, like i said, stock cranks are balanced to what the rod and piston combo is SUPPOSED to weigh, not what it actually weighs. casting and machining differences will throw the weight off some, causing all rotating assemblies to be balanced differently, some off by more, some less.

joecar

I think you will be better off if you find a way to remove the broken bolt and fix the threads (either by installing a thread insert or drilling/tapping for a bigger bolt).

Sales3@Texas-Speed

iTrader: (2)

Couldn't have said it better myself!

trey1010

iTrader: (3)

I had to tap the end of my crankshaft. My bolt also broke off and there was no way I was going to be able to remove it. Tapping it was very simple and didn't take long (hour) and it has remained very tight since I did it about 10k miles ago

oxblood!z28

I'm understanding the reason to balancing the crankshaft thanks guys.

I've tried removing the bolt with drilling a hole to use an easy out but I had no luck. I would tapp the snout but I'm worried that something catastrophic would happen down the road. I'm still wondering what the cons are if I tapp the snout and go that way. I miss my car and would like to get it back on the road I'm sure some of you gys can relate.
@trey1010 what size tap did you use for the end of the crankshaft?

oxblood!z28

To the top for today

bww3588

iTrader: (49)

use a tap one size bigger than the factory bolt. it should tell you what size drill bit to use.

LS1-450

iTrader: (33)

This.

oxbloodz28!, Re-tap it. It's not that big of a deal & far less expensive than buying & balancing (yes, you would need to balance). Just start w/ small bits until nearly all of the old bolt is removed, then use the bit for one tap size larger, then tap it. I have done it & run several thousand miles on the crank since, without issue.

bww3588

iTrader: (49)

I agree with LS1-450 except the need to re balance part. All ls1 cranks are balanced the same, no need to balance if going back in a stock rod stock piston engine.

ls1fst98

iTrader: (3)

I'd look for a deal on a crank and Put new bearing and rod bolts in to freshen it up. But that's my opinion. Guess it depends on how many miles are on the engine.

trey1010

iTrader: (3)

THE size was 10-3/4 I believe. I used a taper tap and then a bottoming tap.

ls1fst98

iTrader: (3)

Aren't the crank threads metric?

trey1010

iTrader: (3)

?? I tap the end with that tap measurement i believe then used a different shorter fatter bolt. So i dont think if it was metric it reallys matters.?

ls1fst98

iTrader: (3)

Oh ok gotcha. I was slightly confuses but I got what youre saying now, lol my bad a little slow on the uptake sometimes. What would you torque it down to? The arp spec? Or the stock specs?