CRG Discussion Forum

Camaro Research Group Discussion => Restoration => Topic started by: Dusk_Blue_Z on March 03, 2018, 02:12:16 AM

Title: 1178 Crank Question
Post by: Dusk_Blue_Z on March 03, 2018, 02:12:16 AM
I have two 1178 cranks that haven't been ground. Brought them to a crankshaft shop and they magged both of them and found many small hairline cracks. Is that normal for these particular cranks? Thanks.

Title: Re: 1178 Crank Question
Post by: 69Z28-RS on March 03, 2018, 04:36:58 AM
I would guess that the 'hairline cracks' are only in the surface of the journal, unless the machinist had a better idea... turning them 0.010 might totally take care of them?   
Title: Re: 1178 Crank Question
Post by: bcmiller on March 03, 2018, 03:21:53 PM
They found hairline cracks, but what else did the say or recommend?
Title: Re: 1178 Crank Question
Post by: Dusk_Blue_Z on March 03, 2018, 06:14:33 PM
They said I could have them ground but they won't warranty/guarantee that they would come out clean. I'll get one of them ground and see how it comes out.

I just found it odd that cracks were prevalent in both. Makes me think small hairline cracks are 'normal' for these cranks. Thanks for the replies.
Title: Re: 1178 Crank Question
Post by: 69z28302 on March 14, 2018, 01:42:21 AM
I would get a second opinion from a different shop and see what it say's
Title: Re: 1178 Crank Question
Post by: Tx-Z 302 on March 15, 2018, 01:48:00 AM
I'm curious if it isn't heatchecks vs cracks, I would get a second opinions to the value of the cranks.
Title: Re: 1178 Crank Question
Post by: 69Z28-RS on March 15, 2018, 02:37:51 AM
It could be a function of 'heat' and the tufftride surfaces put on those cranks;  I think cutting a few thousands will eliminate both... :)
Title: Re: 1178 Crank Question
Post by: Stingr69 on March 15, 2018, 12:59:11 PM
50 years of 1178 cranks and you have TWO outliers????  Second opinion is warranted. 
Title: Re: 1178 Crank Question
Post by: L78 steve on March 16, 2018, 01:55:27 AM
Thump the flange end of crankshaft on a concrete floor. It will have a distinct sound if its cracked. Your crank shop should know this.
Title: Re: 1178 Crank Question
Post by: bcmiller on March 16, 2018, 09:56:13 AM
Find a different shop.
Title: Re: 1178 Crank Question
Post by: Kelley W King on March 16, 2018, 03:14:36 PM
I think I would look elsewhere also. I have had 2 sets of heads deemed worthless by two different people. Running both today.
Title: Re: 1178 Crank Question
Post by: Arch Stanton on March 16, 2018, 11:22:41 PM
Did he say they were junk, but still offered to take them off your hands?