Solid cam damage diagnosis help

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Lil Demon

Lil Demon

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Calling on the solid cam experts here. I am working on a small block with a solid flat cam. The engine only has about 100 miles on it, engine was built and sat for about two years before turning on. It was generously lubricated during assembly but the FI system failed to start up successfully and went to carb. Once fired up engine was run at the recommended sustained over 2k rpm for 20 minutes. Once vehicle completed car was driven for roughly 100 miles and a tapping sound began. Valve lash checked and was found to be between .020-.023 (recommended was .010-.012) readjusted and oil changed. Noticed a lot of metal in the motor oil. High Zinc oil was used from beginning. Drove and noise went away but was concerned for the amount of metal in oil. Pulled motor out and disassembled. Confirmed lobe damage just not what I expected to see. Lifters all look perfect btw. Here are some pictures. TIA

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What spring pressure did you use when breaking it in........That looks like the spring pressure was not dropped or reduced when the cam was breaking in.
 
Lil Demon said:
Calling on the solid cam experts here. I am working on a small block with a solid flat cam. The engine only has about 100 miles on it, engine was built and sat for about two years before turning on. It was generously lubricated during assembly but the FI system failed to start up successfully and went to carb. Once fired up engine was run at the recommended sustained over 2k rpm for 20 minutes. Once vehicle completed car was driven for roughly 100 miles and a tapping sound began. Valve lash checked and was found to be between .020-.023 (recommended was .010-.012) readjusted and oil changed. Noticed a lot of metal in the motor oil. High Zinc oil was used from beginning. Drove and noise went away but was concerned for the amount of metal in oil. Pulled motor out and disassembled. Confirmed lobe damage just not what I expected to see. Lifters all look perfect btw. Here are some pictures. TIA

View attachment 1715557557

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I see the tip of the lobe completely missing on the second photo. Looks like double springs used for break in?
 
It failed. There was no substantial lube left on the camshaft when it was started. It sat up too long. Any camshaft break in lube that might have been applied ended up in the bottom of the oil pan.
 
dart19666 said:
What spring pressure did you use when breaking it in........That looks like the spring pressure was not dropped or reduced when the cam was breaking in.
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Assumption is correct, break in was done with both springs installed. Not too sure on what spring pressure is currently being used. I ordered spring pressure tool to verify but cam calls for 360 lbs at full lift
 
Lil Demon said:
Assumption is correct, break in was done with both springs installed. Not too sure on what spring pressure is currently being used. I ordered spring pressure tool to verify but cam calls for 360 lbs at full lift
Click to expand...

I've broken in cams with dual springs for years. Never had a failure. Not one. As long as you use the right break in lube and an oil high in zinc content and follow the correct break in procedure, you won't have a problem.
 
RustyRatRod said:
I've broken in cams with dual springs for years. Never had a failure. Not one. As long as you use the right break in lube and an oil high in zinc content and follow the correct break in procedure, you won't have a problem.
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I am with you on your opinion, that is what I believe happened. engine start up was attempted at least 12 times with EFI, probably went another 2 weeks until the carb was installed and fired up. Being the situation i'm in I am considering just taking out the inner spring for break in either way. I would just hate to have to open it up once more.
 
Lil Demon said:
Assumption is correct, break in was done with both springs installed. Not too sure on what spring pressure is currently being used. I ordered spring pressure tool to verify but cam calls for 360 lbs at full lift
Click to expand...

That would be my best guess at it and I do this for a living.....Spring pressure too high.
 
Had a friend with SBF that hit coil bind and ran, but not good. Got the right springs and ran great afterwards. It was a question, just something to check.
 
I have never pulled the inner spring for breakin and never had a problem. I use Joe Gibbs breakin lube, grease on the cam and on the lifters when assembled. It stays in place and wont drip off. Everything is set up when started so it fires and goes right to 2500 or more RPM then I set it down to 2300-2500 RPM and leave it there.
 
Lil Demon said:
I am with you on your opinion, that is what I believe happened. engine start up was attempted at least 12 times with EFI, probably went another 2 weeks until the carb was installed and fired up. Being the situation i'm in I am considering just taking out the inner spring for break in either way. I would just hate to have to open it up once more.
Click to expand...

It certainly won't hurt.
 
dart19666 said:
That would be my best guess at it and I do this for a living.....Spring pressure too high.
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Thanks, I do this for a living too, just my first time messing with a solid flat cam. If you notice I didn't try passing blame on the manufacturer. I'm a big boy and knew I had made the error, I was looking for counsel to not repeat the same mistake twice. I appreciate the clear and experienced opinions
 
brian6pac said:
I have never pulled the inner spring for breakin and never had a problem. I use Joe Gibbs breakin lube, grease on the cam and on the lifters when assembled. It stays in place and wont drip off. Everything is set up when started so it fires and goes right to 2500 or more RPM then I set it down to 2300-2500 RPM and leave it there.
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My process exactly, down to the brand of oil! except this one sat for 3 years! not the 2 years I originally posted LOL. It was likely a combination of factors I needed to hear from experienced people to help figure it out.
 
Thanks to everyone for the very quick and valued opinion. I already ordered everything and looking to get it back on the road within a couple of weeks. This car was way too fun to let it sit any longer!
 
Lil Demon said:
Assumption is correct, break in was done with both springs installed. 360 lbs at full lift
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That's why.
I can tell you right now with 360 open, assuming its .5-.550 lift... it had to be around 140ish+ seat pressure. I'm not saying the seat pressure is the reason, it was open really. Just wanna be clear. Break in is done at 2200-2800 rpm... you dont need that much control...aka pressure... at break in rpms.
Hypothetically you could run 180lb seat with a solid lifter if you keep the open reasonable.

Start over.
 
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The wear pattern looks terrible to me.
Way off to the edge.
You should check the lobe taper to see what it is.
(There’s either too much taper, or the lifter bores aren’t exactly perpendicular to the cam c/l, or there is insufficient crown on the lifters...... or a little of all of it).

It also appears to be a cam with a rather small nose radius.
Add in the wear pattern way off to one side and the high open spring loads, and it’s easy for me to imagine why there is a piece missing from the nose of the one lobe.
Too much loading concentrated in that one little area...... the material just gave way.

As for the lobe that’s getting squared off on the nose.

The only cams I’ve seen with that specific kind of wear were run with tool steel or Schubek lifters.

Im not seeing a “wear” problem...... it’s a problem with how the nose of the lobes are being loaded.
More specifically....... the load over the nose not being spread across the entire with of the lobe.
 
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The 12 attempted starts didn't help either. What lube that gravity hadn't pulled off the cam over time got wiped off by the lifters.
 
Lil Demon said:
Assumption is correct, break in was done with both springs installed. Not too sure on what spring pressure is currently being used. I ordered spring pressure tool to verify but cam calls for 360 lbs at full lift
Click to expand...

I missed the sprAng pressure. Yeah, I'd say that was a major contributing factor. lol
 
Question......

In the first two pics...... is the cam oriented the same way between the two, or was it flipped end for end?
 
Is that a hole EDM'd in that lifter? We are going to have that done to ours. That is the way to go. It doesn't look like the lifters were spinning freely. Break in is getting the lifters to spin it has nothing to do with the surface. Coil bind as stated above would be something I would check . Break in lube is just what is means "Lube" until they spin free . Then they work like a sideways roller. Your lifters could have been froze in the bores and were not spinning at start up.
 
Looking at the first pic, I’m assuming this is a SBM cam...... based on how the two lobes are basically lined right up.

There is a(at least somewhat) unique feature of SBM cams(older hemi and poly motors might be the same) relating to the lobe taper.
Each pair of lobes for one cylinder have the lobes tapered in opposite directions.
So the wear pattern will be on the opposite side of the lobe.
This makes the lifters spin in opposite directions.

In the first pic, those four lobes are all tapered the same way.
The second pic they’re tapered the other way...... or the cam was flipped end for end before the pic was taken.

I don’t know if it “matters” which lobes are tapered which way....... but all the ones I’ve seen have it where the pair of lifters for each cylinder turn in opposite directions.

In the pic below, from left to right:
#7 I
#8 I
#7 E
#8 E

As seen by the wear pattern, the 1st and 3rd lobes are opposite each other, as are the 2nd and 4th.

C8952D65-9A37-45B9-8C19-B2E7E8F957FC.jpeg


Again...... what the OP has going on is not “wear”.
The lifter didn’t rub that chunk out of the nose of the lobe.
The piece broke away from high point loading.

This is why the lifters aren’t worn.

Assuming the lifter bores are square, my guess is you’d need to have .003 or more lobe taper to see the wear pattern that narrow and so far off the edge of the lobe.
 
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Cam wear is consistently leaning towards the back end of the cam. I though that was weird too. Is that the result of the rear cam plug being too shallow? Not even sure if it makes contact with the about of the cam. The cam is a Hughes grind and yes they’re EDM lifters. What would be the correction then? Btw I did verify lifters would spin freely in their respective bores. They did require polishing to get them to spin freely during assembly

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