Knockin' On Heaven's Door, what to do for a rod knock?

[MrSony]

#7 Rod spun it's bearings in my lil 350 (my fault entirely), and it scarred the crank pretty bad. Toasted the bearings on that journal for 7 and 8 as well. Now, I know I have to have the crank turned, I'm gonna go ahead and get it done on the mains as well as the rod journals. Now, the questions I have is are: are my rods bad since the bearings spun in them, and are the bolts bad? I noticed they were pretty damn hard to get broke loose, although the I torqued them to spec at 40 ftlbs when I built the motor. To my understanding, rod bolts can stretch when the bearings go bad thus rendering the bolts useless and the rods potentially garbage... correct? The cap was still tight and flush against the rod end, nothing was loose or flopping about. Is there anyway to check the stretch using simple hand tools, or does a machine shop have to decide?

 

[pagrunt]

I would let the shop check them out. They will have everything to let you know if they are good, need to be resized or replaced. I had my local shop go thru every thing on my Chevy 350 I picked up since it I found #1 spun the rod bearing. The rod was resized & saved, costing $25. My crank does need to be resized on the #1/2 journal to be good to go but I had a perfect spare to use.

 

[lilbowtie]

If the bearing spun in the rod - resize, replace.

 

[pontiacgp]

I would also want to find out why 7 and 8 were not lubricated

 

[lilbowtie]

I would also want to find out why 7 and 8 were not lubricated

Read his post (Regal has died for the third time) and 7&8 are last on the food chain.

 

[pontiacgp]

Read his post (Regal has died for the third time) and 7&8 are last on the food chain.

I know they are the last ones to get lubricated but they need to be lubricated. I need to find out what actually caused the failure before I put everything back together

 

[pontiacgp]

here is an article with tips to improve the oiling system in a Buick 350

http://streettechmag.com/2015/08/04/buick-350-engine-build/

 

[64nailhead]

What and why are the questions.

I should have looked for the other thread 1st I guess - found it. Disregard my questions- I'll ask them in the other thread.

 

[UNGN]

here is an article with tips to improve the oiling system in a Buick 350

http://streettechmag.com/2015/08/04/buick-350-engine-build/

Most people reading that stop reading at the first paragraph and say "mental note: never build a Buick 350".

If a motor can literally explode just driving down the highway at 70 mph, that isn't one I'd be in a huge hurry to build.

 

[MrSony]

I've read that article 100 times. for a motor to grenade like that, I'm willing to be he wasn't "just driving". And as for why the rods weren't lubricated, I'd say 6,000rpm on a stock bottom end is what did it. Repeated 6k rpms, mind you. Not just whacking it once and it broke. Basically 5,000 miles of abuse.