427 engine noise in my Kirkham :(

[ng8264723]

Well the engine is making a metallic noise. My enigne builder came over and we took the valve covers off and everything looking good. The noise is in the front of the engine but difficult to identify which cylinder even with a stethoscope. So I gotta pull the engine. I'm so bummed

[Apex_speed]

Originally Posted by ng8264723

Well the engine is making a metallic noise. My enigne builder came over and we took the valve covers off and everything looking good. The noise is in the front of the engine but difficult to identify which cylinder even with a stethoscope. So I gotta pull the engine. I'm so bummed

Sorry, engine problems are the among the most frustrating! Maybe you can use it as an opportunity for a bit more power?!

[rodneym]

Describe "metallic"?
From the snout?
Did you unbelt and listen?

[ng8264723]

Well I pulled the engine. It was the front rod bearing, it spun. I am not sure what caused tis since I never overreved it. I wonder since it sits somlong if I need a prelube? I'm bummed this season is done. I will post pics later. The sucker heated up pretty good. I hope the rod is fine. It has plenty of poer it is a 482 engne. That is enough! I once made a big blunder years ago. I installed the oil cooler lines backwards. I had no oil pressure at idle. I wonder if that was the culprit? I never drove it like that I shut her don and saw my mistake right away

[Gaz64]

I would be looking at poor oil supply from the the front main bearing, that's the path of flow to the front rod bearing, NO. 1 rod.

[ng8264723]

Pics of failed rod bearing

[Gaz64]

So either the oil passage is blocked/restricted, or the bearing outer edge is to close to the crank fillet restricting the oil flow leaving the bearing, or the bearing crush was insufficient.

Many guys does not measure bearing crush, it is what holds the bearing in the rod.

Now you need a full engine rebuild.

[blykins]

One thing I see is that you don't seem to have much rod side/side clearance on that rod pair.

Another thing I see is that the chamfer on the rod looks like it's been possibly running against the fillet on the crank rod journal.

If it's not those two things, then it could be a cracked rod journal. Normally, when you can find no other smoking gun and you have a spun rod bearing with the main bearing that feeds it looking good, then the crank could have developed a crack on that rod journal. When that happens, it bleeds out and you will have less oil getting to the bearing.

[Gaz64]

Can we see a photo of the crank with the other cap off please?

[Dominik]

Check also your oil supply, starting from the pickup, then the inside of the pump.
Sorry to hear about your misfortune..

[eschaider]

My thought processes are going down similar paths as Brent and Gary. If, as I suspect, the other bearings are not spun then you don't have an oil delivery problem. The bearings farthest from the oil supply will always fail first, not last if you have an oiling problem.

Something awry has happened to that rod bearing and possibly others. When you use a full radius crank you need to use narrowed bearings. Many times the bearing manufacturers will offer such a bearing and other times they do not. As Brent suggested the side clearance also looks very tight. When you assembled the engine where did you set the side clearance?

My suspicion is that you used a standard rod bearing and it was too wide to clear the radius the crank grinder cut into the crank. FWIW full radius cranks are stronger than the same crank with an undercut radius but, you need to use narrowed bearings to clear the radius or the bearing will spin in the rod.

Bearing manufacturers make narrowed bearings for common race applications usually SBC, BBC and Hemi engines and an occasional other. If you use a crank that has full radius journals and your bearing manufacturer of choice does not offer a narrowed bearing the job falls to you to narrow the bearing.

Lets say your crank uses a 0.100" radius on the journal, that means you should narrow your bearing width 0.100" on the side of the bearing closest to the radius to clear the radius. Rod bearings are usually set back slightly from the radius facing side of the rod. The minimum amount you will have to trim a bearing to clear a radius is the crank journal radius less the bearing offset in the connecting rod.

Crank manufacturers vary the radii they use usually between 0.100" and 0.125" depending on the crank's intended usage. The 0.125" radii are usually reserved for supercharged Chrysler and BBC cranks and the 0.100 radii is used for most everything else.

When I did a quick search of my Mahle (Clevite) and King Bearings catalogs I did not find any narrowed bearing offerings for 427 engines. That doesn't mean they don't exist but it does mean you would have to make a special effort to find them or make them yourself the way we did decades ago.

My bet is you used regular of the shelf bearings for the assembly and one was just too close to its crank journal radius and made contact. At that point the rest is history.

Your rod journal might be salvageable without cutting the crank. Your crank manufacturer could better advise you on that. If the failure was because of OEM bearing widths being used with a radiused crank journal then, I suspect there may be other wounded journals as well. If there are, you will find them as your disassembly continues. In the FWIW bucket, it would be interesting to see what the sister bearing on that journal looks like as Gary has already asked.

There are other plausible explanations also but standard width bearings on radiused journals almost always have an unhappy ending.


Ed



p.s. the big end on that rod will most likely require resizing to get its proper diameter and bearing crush restored.

[blykins]

If I recall, it’s a 482, which means it has an aftermarket crank that uses BBC rods. Bearings are available.

[eschaider]

That's good news Brent. I am not FE stroker crank knowledgeable or familiar. The use of BBC rod bearings means the builder had the opportunity and presumably used the correct narrowed bearings. That takes the bearing width question off the table and we are back to looking for other potential gremlins.

In the other gremlins bucket, as you previously suggested, the side clearance appears to be quite small. While pictures can be deceiving, the two rod caps did look suspiciously close together. Of course there were no fasteners in the damaged rod. To the OP, it would be helpful to know what you set your rod side clearance to. If you are not the builder you can measure the side clearance with a set of feeler gauges.


Ed

[Dominik]

"If, as I suspect, the other bearings are not spun then you don't have an oil delivery problem. The bearings farthest from the oil supply will always fail first, not last if you have an oiling problem."

Good point here, while I compared to a chevy with the same failure. Chevy pumps sit at the other end.

[eschaider]

I just noticed something in post #6 pic #2.

It appears the upper insert is still in the rod. Look at the edge of the insert adjacent to the crank pin radius. It appears all crumpled up against the crank pin radius. The other end of the insert appears to be properly aligned with the inside edge of the connecting rod.

It appears from this pic that the bearing was not narrowed.

To the OP:

If you get the bearing part number off the back of the bearing a quick check of the manufacturer's catalog will show if it is a std width or narrowed bearing.


Ed

[Gaz64]

Looking at the same pic, to me there is a connecting rod hard on the crank pin, with no shells present.

My bet is both halves came out with the cap.

This looks like the unlucky one to fail first.

Insufficient rod side clearance, total of three clearances looks like .006, would be better at .015.

Wrong shells used for radiused fillet crank versus rolled fillets.

Was bearing crush measured in the rods PRIOR to installation in the engine?

[eschaider]

There might be an upper brg shell still present, Gary. The pic clarity makes it hard to discern the different pieces but it appears there is an upper peeking out at the end of the yellow upper rod bearing arrow.



Bearing shell present or not, the manufacturer's part number off the back of the bearing is going to tell the story.

OP can you post up the part number?

Ed

[Gaz64]

I can see that, but I thought it might be a trick from the background light, or flash etc.

We the need the OP to respond.

He needs to remove a bearing that is not damaged to check the bearing part number.

I would also like to know the bearing crush measurement.

[ng8264723]

Will look when I get home. I’m in Bermuda

[Gaz64]

Ok, we'll all be here to help further when you are ready.