Re: Steel verses cast cam followers
Posted: Thu Apr 14, 2016 9:59 am
Steel cam and steel followers can work together provided a number of things are done. Steel cam followers are good as they are stronger and lighter and can be supplied in thinner top pad thicknesses which are needed for high lift cams.
I presume the same supplier was all QED if you got QED 420 cams. If you have the following setup its probably OK for steel cams and steel followers:
1. Phosphate or DLC coating - you have phosphate which is good
2. Not too great a spring load - how much is to much is hard to say more than 220 ;bs on the nose leads to failures in my experience but if you have Q55 springs that QED normally supply with the 420 cam you will not have to much spring load
3. Use a good assembly lube - did they give any instruction on this ?
4. Run it in carefully - use a good running in oil
Ideally the cams are 5 or 10 Rockwell C hardness unit difference from the followers which are typically nitrided and around 60 Rc hardness. This small difference in hardness helps to prevent galling on running in also. Personally I would not build a full race engine with strong 200 lb nose load valve springs for high revs with a steel cam but I know people do and I believe they generally use DLC coating on the followers.
cheers
Rohan
I presume the same supplier was all QED if you got QED 420 cams. If you have the following setup its probably OK for steel cams and steel followers:
1. Phosphate or DLC coating - you have phosphate which is good
2. Not too great a spring load - how much is to much is hard to say more than 220 ;bs on the nose leads to failures in my experience but if you have Q55 springs that QED normally supply with the 420 cam you will not have to much spring load
3. Use a good assembly lube - did they give any instruction on this ?
4. Run it in carefully - use a good running in oil
Ideally the cams are 5 or 10 Rockwell C hardness unit difference from the followers which are typically nitrided and around 60 Rc hardness. This small difference in hardness helps to prevent galling on running in also. Personally I would not build a full race engine with strong 200 lb nose load valve springs for high revs with a steel cam but I know people do and I believe they generally use DLC coating on the followers.
cheers
Rohan