VAC Rod bearing condition after 13k miles

[Doc Oc]

I finally got my car back last week after having it in the shop for a month getting a new engine installed. I posted on here several times under the impression that it was possible one or more of my VAC rod bearings may had failed. Finally had a chance to pull the oil pan off the old engine tonight and much to my surprise, all the bearings were in perfect shape! I expected to see a broken rod, a busted off end cap, something, given the noise it was making, but all looked great. I didn't take all the caps off at once so no picture of all the shells together, but every one looked just like the one pictured. Crank journals are all fine too, so I'm assuming we have a main bearing failure. I'm going to take the bed plate off this weekend and see what they look like. Will post pics of the results. Wanted to get this up asap just in case anyone saw my old posts and were worried about using VAC bearings....don't be. They've held up wonderfully.

The marks you see on the bearing face are just debris and light reflection. Bearing is perfect.

Edit: attached a new pic of all the shells now that they're out.

[aussiem3]

Thanks for sharing!

[Doc Oc]

No problem. I hope this gives folks some confidence that these bearings can be a permanent fix. There was no wear on any of them at all and I don't see why they wouldn't last the life of the motor. Anxious to get a look at the mains.

[Doc Oc]

Also wondering if anyone has seen a main bearing failure that didn't take out any rod bearings? And if a main bearing had failed to the point where it was loud enough to make me (and the mechanic who heard it) think a rod had snapped, wouldn't there be some slop when trying to wiggle the crank pulley?

[CHE///MIST3]

Cool ! Nice, slippery bearings.. Thanks for sharing.

GM

[BPMSport]

Very nice. Mileage on these bearings?

[Helmsman]

Originally Posted by Mike Benvo

Very nice. Mileage on these bearings?

Title Mike - 13k miles. "First you go blind on are the eyes"...😊

[GMWNashville]

Originally Posted by Doc Oc

Also wondering if anyone has seen a main bearing failure that didn't take out any rod bearings? And if a main bearing had failed to the point where it was loud enough to make me (and the mechanic who heard it) think a rod had snapped, wouldn't there be some slop when trying to wiggle the crank pulley?

No sir-when a main spins it usually creates enough heat to weld bearing material/crank/main pieces together. You wont be able to wiggle it but you can usually see dark areas on whatever cap had the issue. On the S65 I had that spun the front main it was completely locked up.

[Move Over]

Doc, are you supercharged?

[Doc Oc]

No s/c...just bolt ons.

[Doc Oc]

Originally Posted by GMWNashville

No sir-when a main spins it usually creates enough heat to weld bearing material/crank/main pieces together. You wont be able to wiggle it but you can usually see dark areas on whatever cap had the issue. On the S65 I had that spun the front main it was completely locked up.

OK thanks. Engine isn't locked either...cranks turns freely.

[pbonsalb]

Interesting. Hope it was not a transmission or clutch problem instead. I fused a clutch at the strip before and also broken a transmission. Let us know when you find the culprit.

[Malek@MRF]

Been saying this for a while now. These bearings are tried and true. I have personally disassembled a half dozen S65's with 20K miles or more on them with these bearings installed, and they always come out flawlessly. 3 engines were also disassembled that were mostly used for racing, and in those cases the bearings came out perfect as well. None of these engines were torn down for failure or damage.

[Doc Oc]

Originally Posted by pbonsalb

Interesting. Hope it was not a transmission or clutch problem instead. I fused a clutch at the strip before and also broken a transmission. Let us know when you find the culprit.

Thankfully clutch/tranny are doing great with the new engine. I'm really kind of stumped. If any of you have heard an engine throw a rod, it sounded exactly like that sounds right before the block gets vented...but the engine never quit running or seized and all rods are fine. And if a main bearing failed to the point where it sounded like that, I'm surprised the rod bearings were unphased.

[Doc Oc]

Originally Posted by Malek@MRF

Been saying this for a while now. These bearings are tried and true. I have personally disassembled a half dozen S65's with 20K miles or more on them with these bearings installed, and they always come out flawlessly. 3 engines were also disassembled that were mostly used for racing, and in those cases the bearings came out perfect as well. None of these engines were torn down for failure or damage.

You were dead on. I was surprised that they came out so flawless. Even with only 13k miles, judging by the shape of the oem bearings I'd expect some sort of wear. I'm actually going to install them in the new engine once the temps drop...

Now if I could only figure out what DID cause the problem

[deansbimmer]

Originally Posted by Doc Oc

You were dead on. I was surprised that they came out so flawless. Even with only 13k miles, judging by the shape of the oem bearings I'd expect some sort of wear. I'm actually going to install them in the new engine once the temps drop...

Now if I could only figure out what DID cause the problem

I haven't looked into any of your other posts, but I've seen a bad VANOS with no oil pressure cause racket that sounded like a spun rod.... Something to consider.

[Doc Oc]

Coincidentally the engine has always had a very loud cold start rattle. However, before it popped I noticed increased oil temps and a loud metallic tick that I assumed was from the bearings. The next start after I noticed the tick is when it started banging like a rod had let go.

[deansbimmer]

The vanos adjusters have a pin inside that holds the cam's position before pressure builds. If the pin doesn't seat or is broken then it will clatter very loudly. This scenario won't usually present any codes either. This is far fetched but possible.

If it's not a main bearing then I would look there next.

[Doc Oc]

Thanks...hoping to get to it tonight.

[Rajmun340]

Originally Posted by Malek@MRF

Been saying this for a while now. These bearings are tried and true. I have personally disassembled a half dozen S65's with 20K miles or more on them with these bearings installed, and they always come out flawlessly. 3 engines were also disassembled that were mostly used for racing, and in those cases the bearings came out perfect as well. None of these engines were torn down for failure or damage.

This ^^. These bearings had already proven themselves on a sc S65 a couple years back. The coating Molybdemum Disulfide (MoS2) is superior to any other coating material available on the market including the Mahle clevite coating based on material properties over temperature and water content in the oil. Just like I insisted years ago that the problem was never a clearance issue but an oil / bearing material mating issue , this is now proven by the number of spotless VAC Callico bearings checking.
Meanwhile people who marketed their own bearings alternative under the false assumption that "insufficient clearance" was the problem are now proven wrong again and again, calling the VAC bearing a "stopgap" solution on their website is false and misleading.

[Doc Oc]

Keep in mind these VAC bearings open up clearance nearly as much as BE....

[Malek@MRF]

Originally Posted by Doc Oc

Keep in mind these VAC bearings open up clearance nearly as much as BE....

The original coated VAC bearings did not however, and those bearings paired with the correct ARP hardware, also exhibited zero wear.

There is no question that the bearing clearances on these engines are far from where they should be and operating in a dangerous catastrophic range, but there are other factors involved too.