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Old 04-11-2021, 08:39 PM   #1
68PanelTruck
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Does this camshaft look bad?

Hi guys,
I'm in the middle of restoring my 68 Panel with a 396 and need an opinion on the camshaft. I pulled the intake to paint it and replace some leaky intake gaskets. Looking at the camshaft from above it definitely has some shiney wear marks on the lobes but I'm not sure if it is ok to run as is or do you think it should be replaced?

I bought the truck almost a year ago and drove it a total of about 10 miles before starting work on it. It started and ran ok but the clutch was shot and the oil pan was leaking like mad so I really didn't get to drive it. The speedo says 78,000 but it probably went around once. I will be changing out the oil pan and oil pump.

My original goal was to fix the oil leaks and fix the rest of the truck (rust repair) and then, maybe down the road, put a mild cam in it. If the cam looks OK as is I'll probably leave it in and change it out at a later date. If you guys think it's a no-go then any recommendations on a mild street low RPM torque , say from 1500-3500 RPM? It will have cast iron exhaust manifolds and a Performer intake. Have a look at the pics:
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It's not rust, it's called patina

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Old 04-11-2021, 11:14 PM   #2
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Re: Does this camshaft look bad?

From the pictures the cam doesn’t look bad, if you see pitting or any kind of scuffs or a light grooves. In which where possible metal to metal contact, then of course you would have to replace. If it was me, as long as you are this deep into it. Disconnect and block off the fuel line to the pump, have someone crank the motor over or connect a remote starter button in line and watch the opening and closing of valves to look for a flat cam lobe or lobes. If this would come out with good results, then loosen rocker arms one by one and remove push rods inspection of push rods for straightness and look at each end for metal fatigue. Now removal of lifter, look at bottom of lifter for pitting, not flat ( mushrooming of lifter). Now you can do another visual of cam lobe. If everything looks good, making sure that you keep each lifter in the same hole that it came out of. Put back together, adjust the rocker arms 3/4 turn after 0 lash. Use good quality gaskets! I prefer Fel Pro gaskets and use Napa sells Permatex the right stuff gasket maker.don’t go crazy with it, you don’t need a lot.
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Old 04-12-2021, 08:38 AM   #3
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Re: Does this camshaft look bad?

Thank you for your reply. Good to hear that it is not obviously shot. What you said about inspecting it further makes sense and I think I'll do that now that it's torn down this far. I all ready have the starter and fuel pump out but I can turn it by hand easy enough with the spark plugs out. If everything looks ok, I'll run it as is. Thanks again.
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Old 04-12-2021, 03:36 PM   #4
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Re: Does this camshaft look bad?

I think I would go 1 step further and use a dial indicator to measure the lift of each lobe. All the intakes should be the same and all the exhausts should be the same. You should be able to get the lift measurement from a repair manual or someone here may know.
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Old 04-12-2021, 07:14 PM   #5
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Re: Does this camshaft look bad?

The lobes look great to me. If all the rocker arms are moving about the same amount it should be fine. You should see the rough pitted cams Honda used to put in their motorcyles and they would last almost forever. I bought a brand new one once and was shocked at how rough it was. It worked fine.
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Old 04-12-2021, 08:06 PM   #6
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Re: Does this camshaft look bad?

Quote:
Originally Posted by tdangle View Post
I think I would go 1 step further and use a dial indicator to measure the lift of each lobe. All the intakes should be the same and all the exhausts should be the same. You should be able to get the lift measurement from a repair manual or someone here may know.
Good idea thanks. I think I have the cam specs in the shop manual.
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Old 04-14-2021, 12:33 AM   #7
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Re: Does this camshaft look bad?

68, look for lobes that are shiny all the way across the lobe. Those will bad. The very peak of highest lift can look a little funky, and still be good. Good lobes should have wear on the back half of the lobe only, all the way around.
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Old 04-14-2021, 09:08 PM   #8
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Re: Does this camshaft look bad?

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Originally Posted by 68Gold/white View Post
68, look for lobes that are shiny all the way across the lobe. Those will bad. The very peak of highest lift can look a little funky, and still be good. Good lobes should have wear on the back half of the lobe only, all the way around.
I'm going to take a closer look this weekend but from what I can see know it looks like the peak of the lobes are shiny.
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Old 04-14-2021, 10:02 PM   #9
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Re: Does this camshaft look bad?

If it’s a stock cam the lifter won’t move more than a 1/4 inch.
Big block rocker ratio is 1.7 to 1.
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Old 04-15-2021, 03:51 PM   #10
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Re: Does this camshaft look bad?

The cam lobes shown dont look too bad....I would be more interested in the face of the lifters....

If you decide to pull the lifters to investigate...make absolutely sure you keep the lifters in order matching the original cam lobe it is running against.

If the lifters are pitted on their faces I would be replacing both the lifters set and the camshaft and timing chain and hear set....

Flat tappet cam lobes are tapered across their faces and lifter bases are not exactly flat, they have a small radius across their face....these two attributes make the lifter rotate in the lifter bore to minimize wear...if a lifter does not rotate, it will fail...(roller lifters are a different animal)....

Here is an interesting tech write up on flat tappet cams and lifters...

https://www.hotrod.com/articles/chec...-lifter-bores/

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Old 04-15-2021, 09:43 PM   #11
68PanelTruck
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Re: Does this camshaft look bad?

Thanks guys. I have some investigating to do.
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