Datsun Roadster Forum-311s.org

Lots of great choices for you1

https://www.datsunrestorationproducts.com/shop-13

BEST, JT

Good deals!

Whoa!! Tell me about the RB Cam! Which would be better to take advantage of my oversized header ?

How is the duration measured? Total duration or measured at .050

That's a really good question. First these are all street/autocross cams with the RB and the C being the most radical. None are full race cams.

As the link says, the A,B and C cams are exact copies of Nissan cams. The numbers displayed for the Nissan Cams are measured more like Nissan did which was somewhere in the .010-.025 ~.017" lift point.

So if using the "american standard" of duration at .050 the Nissan grinds would be 25 or 30 degrees less give or take.

The RB and the C pretty similar and are the lumpiest, with about 250-260 degrees at .050". Their total duration is over 330 and lobe lift is similar.

To answer Simon's question, yes the RB would be a fine choice with solexes and his setup. The larger primary tubes moves the optimal rpm range up by 1000 or so rpms so you would want the cam to be "on" (dialed in) for 7.5k-8k+ operation.

...must stop salivating.

Thanks for clarifying the duration specs as I was looking at my Isky noting a 248 duration at .50, which is exactly where I want it, and wondering why the B and C cams had such different durations vs this cam. The Isky has a lot of lift though, .536 (according to the website, it's .499, but per Delta and their cam doctor it was .536). We'll see if the rockers can handle that, the springs are tight but are not coil binding per feeler gauge...