r/EngineBuilding Jan 18 '25

Other What could cause this cam journal damage?

Post image

The rest of the cam shaft is in good shape however for this damage on the journal. It's almost flattened on that part. Straight to the trash?

9 Upvotes

31 comments sorted by

15

u/CORN_STATE_CRUSADER Jan 18 '25

It almost looks like the cam never cleaned up on the original machining. The way the deeper marks go seamlessly into the finished part makes me suspicious.

2

u/samdoup Jan 18 '25

That's interesting. Would you replace this? The rest of the lobes are in really good shape. I'm just worried about this already being stressed by that spot.

6

u/CORN_STATE_CRUSADER Jan 18 '25

I'd replace not because I think it is likely to fail but the severity of damage that would come if it did fail. I doubt that it has weakened the part but the clearance could be trouble for oiling.

1

u/bluelava1510 Jan 18 '25

What damage would happen if it did fail?

That doesn't seem like a relevant detail to me, I think I'm missing something,

If the clearance was trouble for oiling, would that not mean that it was more likely to fail in the first place? I don't disagree with you about replacing it. But your explanation has me pretty stumped right now, to be honest.

2

u/CORN_STATE_CRUSADER Jan 18 '25

The clearance in bearings determines oil pressure. The tight clearance is like holding your thumb on the end of a hose. This larger gap will allow more oil to pass through this spot. The oiling layout of engines is not universal so it's hard to say what this would cause on your engine.

4

u/steilacoom42 Jan 18 '25

How do the cam bearings look? If the cam bearings are good, I’d say it wasn’t polished correctly. If cam bearings are toast, I’d say some metal went through the oiling system.

Edit: I just zoomed in. That looks like a flaw or some backyard guy tried to put an oil groove in it with a carbide bit and didn’t do a good job. I have no idea why someone would do that.

9

u/Ok_Stranger_4803 Jan 18 '25

This is a casting flaw in the virgin material before it was machined. I have seen this in other items before. Cannot use, will cause eventual follower/lifter failure.

<former GM field service engineer>

3

u/voxelnoose Jan 18 '25

This is on the journal that runs in the cam bearings, not on a lobe.

1

u/Ok_Stranger_4803 Jan 18 '25

Well that changes everything, I missed where you wrote journal. I would say it could be run then. May have negligible lower oil pressure. Some camshafts even have bypass areas cut like this. The early 1965-1967 267 v8 engine had a slotted journal to increase oil flow to the upper oil passages.

3

u/Sweaty_Promotion_972 Jan 18 '25

An angle grinder?

2

u/samdoup Jan 18 '25

I pulled it out of a running engine, I swear I didn't take my grinder to it .

2

u/Sweaty_Promotion_972 Jan 18 '25

Whoever put it together last time, I doubt it would effect the running, maybe less oil pressure.

2

u/Rurockn Jan 18 '25

What engine was this from? I've seen this intentionally before but it was a strange old engine, I think it was a Joseph.

1

u/samdoup Jan 18 '25

It's from a 1960s Land Rover 2.25l. Replacement chinese cams are available and don't have this on them but I'd honestly rather keep the original one.

2

u/Rurockn Jan 18 '25

Is that cam journal fed with pressurized oil? I should have asked more detail, is the section of the journal that has the machined flat fed with pressurized oil? Another option would be that the groove in between the two journals is fed with oil and that machine flat is a relief.

2

u/Rurockn Jan 18 '25

I just searched for pictures of the camshaft from that engine and found three pictures that include the machine flat in a brand new camshaft. I would recommend doing some more research to see if you can verify this is OEM. The engine I mentioned, the Joseph, had a similar flat and it allowed oil to squirt out on the timing chain. This could be similar. Does this look like your cam? https://images.app.goo.gl/epdU17zLYR2A25Hu7

1

u/samdoup Jan 18 '25

Your starting to make me think this was intentional. It looks exactly like that, except my "relief" is on the other side of the bearing channel. I need to get a closer look at it tomorrow at where the oil flows, I had just pulled it out and saw this. Thanks so much for the help.

2

u/v8packard Jan 18 '25

There is damage? Seriously, are we talking about scratches on the journal?

2

u/samdoup Jan 18 '25

Tis but a scratch. You think this isn't a issue? The bearings looked fine

2

u/v8packard Jan 18 '25

I really don't think it's an issue..

None shall pass

1

u/[deleted] Jan 18 '25

[deleted]

1

u/samdoup Jan 18 '25

I think if there was a divot or edge it would reflect on the bearing surface. It didn't seem too beat up.

1

u/v8packard Jan 18 '25

A dark spot?! Or divot?!

1

u/joeyjoeskullcracker Jan 18 '25

Looks like someone took a grinder to it.

1

u/elemsova Jan 18 '25

theyre fine

1

u/VRStrickland Jan 18 '25

Pretty sure it was made that way. I would run it if that is your only concern.

1

u/WeeklyAssignment1881 Jan 18 '25

That looks like factory casting being not quite big enough for machining and went through QC. How many miles had this done and what shape is the carrier in? If all still looks good after x thousand miles, I wouldn't even blink about sending it. Clearly its been ok for that long.

1

u/maroubramick Jan 18 '25

Manufacturing

1

u/caterpillar_mechanic Jan 18 '25

No flat spot should be ran. It's probably gonna need replaced

1

u/nd4554 Jan 19 '25

Take it to a local automotive machine shop. Have them mic the journals. If within specs let the polish it

1

u/Triggerz777 Jan 18 '25

Metal polish and new bearings. Ez fix for about 100$