Cam regrinds feasible? (roller regrind)

[Greg Hermann]

>You can do some regrinding to rollers, I did, but it was almost not worth
>it. The problem that I was told is that if you do too much you need to have
>it re-heatreated, and then it typically gets out of wack in terms of
>straightness or  so he said. They can take some off and change the profile
>a bit, but you need to check with a grinder that can do it to see how much
>and actually what it will cost. In the long run, more problems then it's
>worth, just get the grind you want and save the exercise.
>
>Sandy

Yep--Roller cams are generally made out of 8620 steel--a gear steel, like
is used for ring and pinion gears. These cams are case hardened, using
copper plating to mask the parts of their surface (everything but the
lobes)  which do not get the high carbon case (plate the whole thing, then
grind the copper off of the lobes). I think the carburized case is only
.030 to .050" thick, and you really need most of it for the lobes to live.
Re heat-treating such a cam is not at all simple to do properly--you would
have to rough grind to new profile, re plate, grind plating off of lobes,
recarburize, and then finish grind.  (If you want it right.) Pretty likely
to be every bit as expensive as a new one.

Just get one, new, the way you want.

Regards, Greg
>
>At 10:49 AM 5/1/99 -0700, you wrote:
>>well here's the last of my q's that have gone unresolved off other
>>resources....
>>
>>Local super comp dragster racing team has been selling of some unused new
>>stuff in the local penny ads.  They have one custom Bruce Crower ground
>>roller cam, 650 lift, 300 duration w/ 105 centre left brand new that's too
>>conservative for their efforts of late for $100CD.  They sold a 2nd one
>>same specs to a 'vette owner who had it reground to 575 lift, 112 lobe
>centres.
>>
>>I'll check out the regrind price from the local grind guru's "Shadbolt"
>>(any horror stories on them?  I've only heard good so far), but at their
>>price I should be able to get a reground roller for 30% or so below new and
>>to my own custom specs, assuming their's room in this monster for a 214/218
>>at 114 or 115 or similar (or v. open to reccomendations....).  I know I'd
>>need the Bronze distr. gear for $40CD or so as well.
>>
>>Just checking this out.  For their cost I might just pick it up and decide
>>later as I don't think  resale 'netwise would be hard to break even.
>>
>>thanks again
>>
>>Ross Corrigan  /  Vancouver, Canada
>>
>> '80 327ZX   IZCC#255, Edmonton Z-car Club #44, British Columbia ZCR
>>Life's a journey, not a destination.. Enjoy the pitstops and maximize the
>>straights
>>
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