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School Me on Camshaft Cores
#2727769
12/28/19 04:44 PM
12/28/19 04:44 PM
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Joined: Jan 2003
Posts: 25,618 Rio Linda, CA
John_Kunkel
OP
Too Many Posts
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OP
Too Many Posts
Joined: Jan 2003
Posts: 25,618
Rio Linda, CA
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I admit to being out of touch with the latest in engine parts so a dummy question:
Are all aftermarket solid roller cores billet? Wondering about the suitability of solid roller cores that are compatible with the factory pump drive gear.
What are modern factory hydraulic roller cores made of? Could they be used with solid rollers?
The INTERNET, the MISinformation superhighway
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Re: School Me on Camshaft Cores
[Re: John_Kunkel]
#2728148
12/29/19 09:13 PM
12/29/19 09:13 PM
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Joined: Oct 2005
Posts: 265 Anchorage, Alaska
metallicareload
enthusiast
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enthusiast
Joined: Oct 2005
Posts: 265
Anchorage, Alaska
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I admit to being out of touch with the latest in engine parts so a dummy question:
Are all aftermarket solid roller cores billet? Wondering about the suitability of solid roller cores that are compatible with the factory pump drive gear.
What are modern factory hydraulic roller cores made of? Could they be used with solid rollers? As I understand, yes, and because of that they are incompatible with factory iron (cast?) drive gears. My guess is that a billet core is needed because cast iron is unsuitable due to being too soft for a rolling surface? At least for a cam and springs big enough to bother going through the trouble of going roller
Last edited by metallicareload; 12/29/19 09:16 PM. Reason: Clarity
440, 4-Speed, 3.54 1968, when Dinosaurs ruled the Earth
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Re: School Me on Camshaft Cores
[Re: John_Kunkel]
#2728203
12/30/19 06:46 AM
12/30/19 06:46 AM
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Joined: Jan 2005
Posts: 2,540 Milwaukee WI
TRENDZ
master
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master
Joined: Jan 2005
Posts: 2,540
Milwaukee WI
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If you see a black cam core, it is likely a high carbon steel(51xx) core. These are lower cost milder lobe candidates. These are also usually the cams you hear about that are compatible (sort of) with iron pump gears. Not all black cams are compatible with iron gears, just the ones with the pressed on gear/ lobe. The core is machined to accept a pressed on iron gear and last/ first cam lobe. They start out as bar stock. They are rough turned into the general shape, (round lobes) then rough milled into lobe shapes so the grinder doesn’t have to work on them all day. Then they are hardened. After hardening, they are finished into the final profile. Copper colored cores are almost always 8620 alloy steel. They start as bar stock. They are turned into the general shape(round lobe) then plated with copper, and rough milled to general lobe shape. the copper prevents hardening in the areas not masked with copper. This allows the core to have a depth of hardness only on the exposed steel, and only at a certain depth. This keeps the rest of the cam ductile so it doesn’t fracture. This why some cams cant be ground/ reground with some lobes or lobe center combination. The final grind can’t break through the surface hardening and still have a durable finished cam. There are also tool steel billets. These are pre heat treated all the way through. The tool steel and heat treat combo are hard enough to be resilient on the lobe surfaces, yet still machinable and not brittle. These are used where you want an “anything goes” type cam. No limits on shape, depth, lobe placement, journal diameter etc....
"use it 'till it breaks, replace as needed"
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