guess i should have done this 1st, what is a good price for a good 8cm cam? i found one for $150.
$50 for a good core.
$150 for a CHEAP stock regrind.
$200 for a good STOCK regrind.
Any NOS core should be reground at this point. There is NO preservative in existance that could keep it's surfaces good for this long except a full vacuum chamber and think of the cost to have operated a vacuum chamber since 1953.
A lobe surface that appears good to the naked eye will easily be rejected under a microscope.
It is far cheaper to use orginal steel lifters than adjustables. They are far better quality, not to mention they make a far superior finished product.
Any NOS core should be reground at this point.
A lobe surface that appears good to the naked eye will easily be rejected under a microscope.
It is far cheaper to use orginal steel lifters than adjustables. They are far better quality, not to mention they make a far superior finished product.
Now Pete, since YOU brought it up, I'm gonna let you show us just how dumb I really am. Please help me understand how a 70-year-old, NOS cam core is going to be "all messed-up" looking at it under a scope, whereas an ORIGINAL (70-year-old) steel lifter is going to be of better quality than an adjustable? How zat work?
Coop
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And how do you control valve clearance then? When a cam is reground, you're going to lose material. Granted, maybe just a few thousandths, but you are still opening up the clearance. Do you sink the valves (not good)? Do you buy new valves and grind to proper clearance (not cheaper, and labor intensive)?
I'm genuinely asking here, not trying to poke.
Now Pete, since YOU brought it up, I'm gonna let you show us just how dumb I really am. Please help me understand how a 70-year-old, NOS cam core is going to be "all messed-up" looking at it under a scope, whereas an ORIGINAL (70-year-old) steel lifter is going to be of better quality than an adjustable? How zat work?
Coop
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Coop, I have to comment on your statement about "dumb". You just lacked info on the subject. Same as I have very little info on round motors although I love to hear them run. I think you are one of the most knowledgeable people on here.
Ya know Pete, I really appreciate the compliment. It ain't that I'm really all that knowledgeable. I think it's more like maybe I have a little more info on a few more subjects than a lot of folks, and that I maybe pay a little bit of extra attention to most of the details, while overlooking the superfluous BS.
Hey, I LOVE round motors, too! So here's one for you. WHY MUST ALL ROUND MOTORS HAVE AN ODD NUMBER OF CYLINDERS PER ROW?
Coop
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You weld the stems and grind to length is how I understand it
There's no way that would be cheaper, as claimed. And I'd have to wonder how well the welded tip would hold up unless it was properly re-heat-treated. I like the idea of using the steel lifter; fewer pieces means fewer related problems, but is this actually the way guys are doing it?
Years ago, I had a flathead cam from an old 59A that I tore down for parts. The cam had what looked like air pockets, bubbles, pores throughout the whole cam. It was that way on the lobes and brg surfaces. I could not believe that it had run for years that way and still looked like it was still usable. Has anybody ever seen anything like that? How could that make it through "quality control"?
Yes, grinding tips is nothing new. It's been done for many, many decades. All the old machines that I've ever seen had that function. But welding them first? Never heard of that, and I have to question it's viability.