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Brief backstory - I started getting some engine knocking noises at around 1.5k - 2.5k rpm. It sounded like a collapsed lifter, so I sent it away to be rebuilt. Today they find this:
WTF could have caused that? It almost looks like the rod has been lacking lubrication or something.
P.S: bonus points for anyone who knows the part numbers for a new rod, crank (dry sump) and bearing
Collapsed lifter, ruined bearings... sure looks like some sort of oil distribution issue. Or maybe some casting sand didn't make it out of the block before assembly.
100% for sure some thing of trash has gotten into the oil & did that to the bearings. Same thing happen to my new motor in my c2 guy wouldn't stand behind it at all. I had a guy to rebuild it & with 30 over pistons & he didnt really clean the block good from that & some of that got down into the oil & did that & worse to almost ever bearing in the crank. I then had to get a diff guy to redo my new motor plus it only took less than 100 miles to do that to my motor...
100% for sure some thing of trash has gotten into the oil & did that to the bearings. Same thing happen to my new motor in my c2 guy wouldn't stand behind it at all. I had a guy to rebuild it & with 30 over pistons & he didnt really clean the block good from that & some of that got down into the oil & did that & worse to almost ever bearing in the crank. I then had to get a diff guy to redo my new motor plus it only took less than 100 miles to do that to my motor...
Thats really worrying. A couple of weeks before it started knocking I performed an oil change and noticed a fair amount of material on the magnetic drain plug I installed when I bought the car:
I thought it was probably just because this was the first oil change the car had ever had (4000miles on odo) and it was just material from the engine bedding itself in?
Another question - My engine builder tells me I need a new rod, bearing and crankshaft. I can understand the crankshaft because he isn't able to machine it, and obviously it needs a new bearing. But why a new rod?
Thats really worrying. A couple of weeks before it started knocking I performed an oil change and noticed a fair amount of material on the magnetic drain plug I installed when I bought the car:
I thought it was probably just because this was the first oil change the car had ever had (4000miles on odo) and it was just material from the engine bedding itself in?
Another question - My engine builder tells me I need a new rod, bearing and crankshaft. I can understand the crankshaft because he isn't able to machine it, and obviously it needs a new bearing. But why a new rod?
That is quite a bit of larger particles on the magnetic drain plug. I have not gotten anything like that is my 2014 C7 or 2nd change in my Grand port (installed magnetic plugs on my first 500 miles change. I just see a small amount of very fine material.
Don't understand why a new crack?? Most mechanics don't have their own crack grinding machines but send it out to a pro. Sure does not look like the journal can't be ground to the next size bearing. I'd also have him look at what caused the oil starvation. Also don't understand the reason for a new rod. What does the builder say is the reason?
The rod needs to be replaced because the big end is not perfectly round. You have to do it right...
John
Sounds like there was more damage than a “Bad Bearing.” Yep, Do it right!
SideBar
Remined of the first engine I rebuilt, a ‘50 Olds (that or a Caddy is what we used back “in the day.”). Bought the engine from a friend, all in pieces except the block literally in peach baskets! Back then the machine shop would come out and mic the block to check wear and taper. I recall the machinist said, “should be OK.” Should was not what I wanted to hear and Hot Rod said the block could be bored 1/8 inches for ‘55 Olds pistons (303 to 324 cid.). Machine shop said they could be in the water jacket, you’ll have to pay up front and buy the pistons from us!
Put the money up (was working part time and ever dime went into that car!). I was getting a mechanics 50% Discount because of a relative in the business so price was not that bad. Engine rebuilding was common back then. Recall having to wait for the pistons to arrive as they mic’ed each one before boring and honing, matching each bore to that piston. Yep, back in the day they also knew what they were doing!
Recall a phone call saying we found 3 rods were “stretched!” No problem as another friend had an Olds engine he was not going to use so gave the shop 8 more rods and said pick the best! He was also taking an automotive class and polished those heads so you see yourself! Got him an “A!”
I used a 4 barrel carb and installed what was called a 3/4 cam. Since that ‘41 Coupe had come with a small cid flathead (60 V8) it also came with a 4:56 rear! Thank goodness for the skinny tires we had back then or something would surely have broken.
Thats really worrying. A couple of weeks before it started knocking I performed an oil change and noticed a fair amount of material on the magnetic drain plug I installed when I bought the car:
I thought it was probably just because this was the first oil change the car had ever had (4000miles on odo) and it was just material from the engine bedding itself in?
Another question - My engine builder tells me I need a new rod, bearing and crankshaft. I can understand the crankshaft because he isn't able to machine it, and obviously it needs a new bearing. But why a new rod?
Man that is a lot for the first oil chg something was not set up correct r something started to come apart. warr work for sure..
with the oil pan being like it is build I will tell you this for sure much more small shavings of bearing in that oil pan & also in the oil pump. Also did your oil pressure drop any at all in the last few days before. Robert
Last edited by robert miller; 07-21-2018 at 09:18 PM.
100% for sure some thing of trash has gotten into the oil & did that to the bearings. Same thing happen to my new motor in my c2 guy wouldn't stand behind it at all. I had a guy to rebuild it & with 30 over pistons & he didnt really clean the block good from that & some of that got down into the oil & did that & worse to almost ever bearing in the crank. I then had to get a diff guy to redo my new motor plus it only took less than 100 miles to do that to my motor...
Robert, i find your theory of trash getting into the oil with an oil filter there hard to believe? Educate me on your guess? I am no trying to trash you I want to be educated if this is a possibility with oil filter in place?
Man that is a lot for the first oil chg something was not set up correct r something started to come apart. warr work for sure..
with the oil pan being like it is build I will tell you this for sure much more small shavings of bearing in that oil pan & also in the oil pump. Also did your oil pressure drop any at all in the last few days before. Robert
Would I have got a notification about low oil pressure? I have to admit that I don’t tend to keep an eye on it.
Happened to me also (more than once) re-trash in oil after rebuild. If every oil passage/plug isnt pulled out and cleaned thoroughly more than once the risk of getting any machining fallout in the bearings, can do damage fast.
Having worked at Machine shops in younger years it happens more than most would want to know.
Pay the money for the 1-2 man shops, guys. Youre asking for it w/cheap mass built crate engines no matter what the warranty.
So is the op’s a factory engine ??? So not under warranty?
Yes it was a factory engine. But no longer under warranty.
Originally Posted by Avanti
What year is the car. Did your buy it used? Sorry, if I missed it here. I'm wondering how long the thing sat around not running, and why.
2014. I bought it a year ago with 3k on the odo. It had been sitting for a while, but I put that down to the U.K. not being a big market for vettes. I put another 2k on it before it started to knock.
07-20-2018, 12:11 PM
Crank and rod toast on LT1 - What caused this???
I then had to get a diff guy to redo my new motor plus it only took less than 100 miles to do that to my motor...
Sounds like there was more damage than a “Bad Bearing.” Yep, Do it right! 
