# Over head cam roller buckets

**URL:** <https://boards.straightdope.com/t/over-head-cam-roller-buckets/831513>\
**Category:** Factual Questions\
**Created:** [March 25, 2019, 5:30pm UTC](https://boards.straightdope.com/t/over-head-cam-roller-buckets/831513 "2019-03-25T17:30:22Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\
**Post date:** [March 25, 2019, 5:30pm UTC](https://boards.straightdope.com/t/over-head-cam-roller-buckets/831513/1 "2019-03-25T17:30:22Z")

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In over head cam engines, the cam follower…nicknamed a bucket…fits around the valve spring and acts upon the valve directly.

[![](https://i.stack.imgur.com/epoP5.jpg) ](https://i.stack.imgur.com/epoP5.jpg)

Now, in high performance pushrod engines  
[![](https://content.speedwaymotors.com/ProductImages/29066200_L_face6982-9dce-41f7-8284-47bd889cad3f.jpg) ](https://content.speedwaymotors.com/ProductImages/29066200_L_face6982-9dce-41f7-8284-47bd889cad3f.jpg)  
and ohc applications which employ a cantilever/rocker valve actuator  
[![](https://www.performancetrends.com/Definitions/Images/Over-Head-Cam-Valve-Train-Lrg.jpg) ](https://www.performancetrends.com/Definitions/Images/Over-Head-Cam-Valve-Train-Lrg.jpg)

a roller is employed to follow a fat cam lobe a regular flat tappet couldn’t handle.

Is it possible/available to have a roller bucket?

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**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\
**Post date:** [March 26, 2019, 10:31pm UTC](https://boards.straightdope.com/t/over-head-cam-roller-buckets/831513/2 "2019-03-26T22:31:24Z")

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Sure. The term of art in machine design is “roller cam follower.”

The only real drawback I can think of in an OHC engine is that it increases the height of the head by a fair bit—maybe 1.1 times the diameter of the roller follower.

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**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\
**Post date:** [March 28, 2019, 12:58am UTC](https://boards.straightdope.com/t/over-head-cam-roller-buckets/831513/3 "2019-03-28T00:58:02Z")

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Image searching “roller cam follower” yields components less at home in an engine and more in a dishwasher.

Indeed, adding a roller to a standard “bucket” would double the length of a cam follower.

Taller roller buckets requiring a relocated cam held in place by taller camshaft brackets, taller valve covers, and longer chains/belts.

Ideally, the upgrade could take place with the engine in the car instead of disassembled on a bench

I figure, give new life to the OHC diesels available from the late 70s to early 90s.

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**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\
**Post date:** [March 28, 2019, 1:17am UTC](https://boards.straightdope.com/t/over-head-cam-roller-buckets/831513/4 "2019-03-28T01:17:47Z")

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> [@Enola\_Straight](#):
>
> Image searching “roller cam follower” yields components less at home in an engine and more in a dishwasher…

Respectfully, so what?

You asked if it was possible, and I answered your question. I gave you the generic name for the component in question and mentioned an obvious drawback. What kind of answer were you expecting?