Cam Follower Wear Rate

**supple** · 05-16-2016 07:29 AM

Hi All:

We all know the follower is one of the maintenance items for our generation and I haven't seen any real measurements done before. As an engineer this bugged me and since I have drop gauges at work, I did an easy experiment (currently still on-going).

DISCLAIMER: My experiment should not be held as law as cam followers all will differ in exact measurements and wear rates are highly dependent on condition of the individual's car, parts, oil levels, how 'spirited' you drive, ECU Tunes, upgraded parts, etc. I am not responsible for any damage to your own cars. You can see my upgrades in my signature, I do oil at 5k and top off a quart at about 4000-4500.

I have since bought two INA cam followers from ebay. The first one (I'll call it CF1) measured at 0.079" brand new on the drop gauge. I just removed it after 5000 miles of mostly highway driving, I do like to hit 4-5k RPM at least a couple times a day. There is basically zero wear in height after 5000 miles, the black coating started rubbing off in the center but the numbers didn't change with any real significance.

I measured the second follower (CF2) new this weekend at 0.069" and have installed it into my car. I think I will measure CF2 after it's run for 10,000 miles and remove/remeasure.

So from what we know, the INA followers seem to hold tolerance new from 0.069-0.079 (from a sample size of 2, LOL) and at 5000 miles no significant wear is measurable. My plan is to find a wear rate and divide by a factor of safety of 2 and consider that my time to check/change out followers.

**I noticed that there could be a slight error in measurement technique since the center seems to wear first, I place the CF face down and the unworn parts of the plane may be hiding the wear at the center point. I could do these measurements as well as height drops next time to both sides of that face separately.

**supple** · 05-16-2016 07:45 AM

Cam Follower 1 (CF1) after 5000 miles:

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**Ray1031** · 05-16-2016 07:56 AM

Will keep an eye out on this thread

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**miA4** · 05-16-2016 08:02 AM

In my opinion, I believe that it all depends on your driving habits. I definitely get on my car and I am currently sitting at 15k miles with about as much wear as you've shown. I will also go on a limb as say that people that have tunes should change their CF at around 15k miles as a precaution. I will be tuning my car later this year and will be keeping CF's on hand for changing regularly.

**supple** · 05-16-2016 08:12 AM

Originally Posted by miA4

In my opinion, I believe that it all depends on your driving habits. I definitely get on my car and I am currently sitting at 15k miles with about as much wear as you've shown. I will also go on a limb as say that people that have tunes should change their CF at around 15k miles as a precaution. I will be tuning my car later this year and will be keeping CF's on hand for changing regularly.

Hence my disclaimer above. And at your point, 15k is where I'm going to bet when I will start seeing any sort of significant wear. This thread was just extra info for people who like numbers :)

**Okedokey** · 05-16-2016 08:29 AM

I like a scientific element, well done. We should be doing the same and adding to it.

**BenMTL** · 05-16-2016 09:25 AM

Subbed.

Great research, keep us posted

**supple** · 07-20-2016 03:44 PM

Took out CF2 after 10k miles and measurement with the follower faced down is .078" and faced up is .825". Basically looked like the images above.

Previous measurement of CF2 @ new was 0.069". The discrepancy could be stemming from the drop gauge or even the flat stone. However considering the range of tolerance new from 0.069-0.079" I would be confident to say the wear rate after 10K is null. I put in CF1 again and will run it another 10K (to total 15k) and remeasure.

**adam044** · 07-20-2016 08:08 PM

Originally Posted by miA4

In my opinion, I believe that it all depends on your driving habits. I definitely get on my car and I am currently sitting at 15k miles with about as much wear as you've shown. I will also go on a limb as say that people that have tunes should change their CF at around 15k miles as a precaution. I will be tuning my car later this year and will be keeping CF's on hand for changing regularly.

With a tune it is recommended to change it between 5k-10k.

Stock 20k-30k.