Superfinishing (Burnishing)

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Comp Cams Factory Tour: How Does a Performance Camshaft Get Made?

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What happens here

The final stage for camshafts is 'superfinishing' (also known as burnishing or microfinishing). This process occurs in a dedicated room using specialized machinery that contains ceramic or porcelain media. The camshafts are tumbled within this media, where the compound and mechanical action smooth out any remaining 'mountain tops' (roughness) on the lobe surfaces, creating an exceptionally smooth, uniform finish. This process does not alter the overall lobe profile but improves surface texture and lubricity, leading to enhanced performance and durability.

Goal: Achieve an exceptionally smooth and uniform surface finish on camshaft lobes.

Tools and materials

Burnishing Machine — Performing the superfinishing process
Camshaft Comp Cams — The item being superfinished
Burnishing Compound — A liquid mixture used in the burnishing process
Ceramic Media — Small abrasive pieces used for polishing

What they say

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exactly what it should do so when you grind the camshaft like when you look at that you could see there was all these little mountain range on there no matter how good whether you grind to a 20 ra finish or 10r8 or 5ra you're still going to have like mountain tops now what super finishing does is it's not like having a a road grader that goes through there and shapes it it's more like having a finishing mower out on fenway you know you go in there and you just take that little rough grass and you trim it off to be all one nice smooth smooth finish so this guy really we can't help it a ton but actually we'll run it and see what it looks like all right let's make a nice trophy out of so we've got a nice little soupy mixture of burnishing compound and if we go through here and run it at about 10 to 20 g's 200 pounds of media in there becomes all of a sudden 2 000 pounds of force equally across the surface of the camshaft and it will go in there and basically just mow the grass it won't fix anything in there that's messy you know if you have a bag cam it just makes it look worse but if you have a good cam it can take a good cam and make it really really good so this might look worse after it's done no it's gonna look pretty okay how does it take you bob you all get 10 minutes around i guess you just have to sit around and wait is that what you do all day two of them running so i'm running both at the same time i'm gonna do some stuff and i'm back and forth so i'm always moving i just don't have anything now to keep it really just going so that's why i was over there what do you do over there i'm polishing cans on the belt polisher over here that doesn't get msc yeah the the steady rest will leave a little line on the girdle so jackson will come over here and make sure that see this this real small line here yeah this is that carbide foot on the steady rest on that akuma grinder so you send it out looking like this people get mad jackson's job is to make people not mad yep quality chance yeah and so he does a great job with this the other thing that he does is like i said when it when the cam runs to the msc if there's any fault in the grinding like the dress was bad or anything like that when he takes it out he's going to look at it really good and he'll be able to tell the light will catch it differently and you'll be able to see things visually that you can almost can't pick out with anything other than prophylope so he's really the last step for quality…

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