What do you think about the condition of my 64 Riviera 425 cam shaft? Do the lobes look ok? Bought the car from the owner's son, he thought the motor was rebuilt with about 200 miles on it (no paperwork). I'm concerned about the dark texture spots on the lobes. It's a CA desert car, so it hasn't been exposed to much moisture. Car was sitting for 14yrs, started a couple of times about 6-8yrs ago, and I had it running for 15 minutes to move it about 3yrs ago. Does this look normal? Or do I got worry?
Kinda looks like a new cam that has just been run in. But gimpy is right you have to pull the lifters (keeping them in order to their matching lobes) to check for cupping or galling. Lifters should have a slight crown.
It appears that unlike other pushrod engines, the Buick lifters are not offset from the cam lobe...Do Nailhead lifters spin?
Most Nailhead engine builders grind the casting flash off from around the lifter bores, so suspect of the quality of the build. I would pull a lifter and look at it.
The cam looks great to me . Like SS said,,,,,it looks like a fresh broke in low mileage cam . The dark areas of the lobe are where the Parkerizing is wearing off,,,like it will from being used . The peak of the lobes still has a patch of dark area ,,,,so the lobes are not worn . The lobes are ground on a slight taper,,,that assist in the lifter being able to spin . Also,,,,the tops of the lifters are all sitting the same in the bores at the base of the lobe . If the lifters were badly worn,,,,,they would be uneven . The peaks of the lobes look uniform,,,,,so I don’t see any need to worry . Unless you are just looking for something to worry about or work on ,,,,,,and spend money . Has it given some reason to suspect an issue ? If it was running and sounding good,,,,,I wouldn’t worry . And besides,,,,it’s a California car,,,,,it should be in great shape . And as far as the casting flash still being present,,,,,,not everyone ground that out years ago . Especially if it was a normal rebuild,,,,,,it cost more because of the labor involved,,,,,and it wasn’t the expected practice back then . I wouldn’t give it a second thought . It looks very good to me ,,,,,I wouldn’t think twice about it . Tommy
looks good to me also, like said above, the wear on one side of the lobe is just what you want. The cam is ground with a taper, this makes the lifters rotate, this looks like it was done correctly. If you are still worried, check the bottom of a lifter or two.
If you polish the ramps on the cam & the convex surface off the lifter face , you might as well pitch the whole thing IMO .
A little time with a dial indicator will tell you about the lobes , a visual inspection of the lifter faces with a straight edge will tell you the condition of the lifters , no need for speculation .
Almost impossible to tell without pulling all the lifters and examining them. Based on your pictures, I would probably run it as is. It is nice an clean inside.
Really appreciate the info guys, thanks to all of you so much. Had my fingers crossed, glad for good news. Been about 20yrs since i've done anything with a cam, I wasn't sure what I was seeing. Once it gets below broiling here in the desert, i'll pull some lifters and see what they look like. I bought some break in oil for it, i'll get some lube for those lobes too. I ran a borescope into the fuel pump opening, the timing chain is a plastic gear, but looks brand new too. Already shopping for a new one. For timing chain sets, is a replacement with iron gears good? Should I pay up for a double roller? TA Performance has one with a bunch a keyways on it, should I advance or retard the cam any?
Isky Rev Lube or equivalent moly paste lube is best for cam . put a quality steel double roller chain/ gear set in & forget it !
If I remember right the factory timing sets were about 4 degrees retarded. They used to do that to lower hp or torque for different engine options and or emissions. If it were me I’d be buying a good double row timing chain set and degree it straight up.
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