Production date codes on Schrick cams - pre or post rocker requirement

[bmw m3 s50]

Hey does anyone know how to tell the difference between the older style Schrick cams that didn’t require the DLC rocker arms to the newer style cams that do require the DLC rocker arms? Is there actually anyway to tell the difference?

[Slideways]

..

I'm aware of 4 variants.

Original - See the picture from Obioban's thread below. Cam looks near identical to BMWs, appears to have been ground from the same blanks. Standout features compared to newer Schricks - hex area to turn the cam is smaller diameter than the shaft, and the flat surfaces of the lobes have a textured finish to them



The rest seem to be variants of what turner calls the new "cast" cams. There seem to have been two variants of the coating, a black one and a light gray one. And now an uncoated variant. All pictured below. Unclear if metallurgy changed during those transitions, nor do I know what the coating is actually made of. Visually asides for the coatings or lack thereof, you can see the hex area is larger diameter compared to the shaft, and the lobes have a smooth finish on the flat surfaces where BMW's and the "OG" have a textured finish. Looking it up, I think the 'coating' is a result of nitriding the cams, still not sure what the significant of black vs grey would be, but that could explain why the 'uncoated' ones seem to be failing - they don't have the surface hardening that is expected.

[bmw m3 s50]

Is it safe to say that the cams that are coated black do not require the rocker arms?

[s54brendan]

Is it safe to say that the cams that are coated black do not require the rocker arms?

They all require them.

[bmw m3 s50]

They all require them.

I don’t believe that is correct. Reading prior treads, there are several reputable members here that purchased Schrick cams before they changed production and used their used stock rocker arms without issues.

I am still trying to confirm which cams were used without the need for DLC rocker arms.

[Gt4]

I have a set of these older 280/272 Schricks cams

[BMWfanz]

I have a set of these older 280/272 Schricks cams

Which mileage on it? Dlc almost gone at working surface. I've bought schricks in 2022 and they already was without black coating.

[Gt4]

Which mileage on it? Dlc almost gone at working surface. I've bought schricks in 2023 and they already was without black coating.

about 40000km

[bmw m3 s50]

I have a set of these older 280/272 Schricks cams

Did these require the DLC rocker arms?

What did you use when you installed them?

Why were they removed after 40,000km?

[bmw m3 s50]

Which mileage on it? Dlc almost gone at working surface. I've bought schricks in 2022 and they already was without black coating.

I assume that your cams definitely require the DLC rocker arms vs the black coated cams?

[Gt4]

Did these require the DLC rocker arms?

What did you use when you installed them?

Why were they removed after 40,000km?

I removed them from a car I bought 2-3 years ago and sell the car after removing all mods from it. They were installed with OEM followers.

They were installed at 42000km and bought the car with 82000km.

[bmw m3 s50]

I removed them from a car I bought 2-3 years ago and sell the car after removing all mods from it. They were installed with OEM followers.

They were installed at 42000km and bought the car with 82000km.

Are you selling those cams or reusing them?

[BMWfanz]

I don’t believe that is correct. Reading prior treads, there are several reputable members here that purchased Schrick cams before they changed production and used their used stock rocker arms without issues.

I am still trying to confirm which cams were used without the need for DLC rocker arms.

My case- i've rebuilded engine with stock cams but rocker arms were bad- in first rebuild i've bought DLC Schrick rocker arms and run on stock cams, now on second maintante with installing Schrick cam over 40k kilometers - there are still DLC on rocker arms. As i undestand- there will be a little more wearness with cams setup, but if you not going to run on mod cams more than 50-70k miles- OEM rockers will be ok if there will be good oil and little service intervals.

[Gt4]

Are you selling those cams or reusing them?

Still not sure if I want to install them in my track car build or not

[s54brendan]

I don’t believe that is correct. Reading prior treads, there are several reputable members here that purchased Schrick cams before they changed production and used their used stock rocker arms without issues.

I am still trying to confirm which cams were used without the need for DLC rocker arms.

That is true -- they're not required if you're in for a nice gamble of needing new camshafts and possibly a blown engine.