Q&A / Tech

Mailbag: Camshaft Lobe Separation, Nitrous Oxide & How They Relate

Got questions?

We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we examine ideal camshaft lobe separation for nitrous applications.

D.M. Pitman, NJ

Q: Can you shed some light on camshafts made for nitrous engines? Why would they have a lobe separation of 112-114 degrees, versus 106-108 degrees for an otherwise identical cam?

A: Here’s the scoop on nitrous cams. To compensate for the additional fuel being used and the large amount of exhaust gases created in a nitrous-powered vehicle, nitrous-specific camshafts are designed with higher exhaust valve duration and lift. The opens the valves earlier and closes them later.

A cam’s lobe separation determines where and for how long peak torque occurs in an engine’s rpm range. On a tight lobe separation, like 106-108 degrees, the engine will build torque quickly and reach its peak early. Given that nitrous works best in the mid- to upper-rpm range, nitrous-powered engines need a wider lobe separation, like 112-114 degrees. With a nitrous-specific cam, peak torque will be spread out over a broader portion of the basic rpm range, with maximum power up top–where nitrous performs best. Hope that clears things up!

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3 Comments

  1. I have las of 112 icl of 108 is this good for nitrous lift is 652 643

  2. I call BS on this, explain how what you are stating works. Your generalized statement is what is wrong with this industry, There are to many variables left out of this question to give an accurate answer.

  3. Darren Mccann says:

    I run a 106 lobe cam with 200 shot work great if u plan on spraying 250 or over then 110 and up will be better but any thing under the 106 cam are faster on nitrous I have a 12.1 compression 358 sbc run 11.30 n/a on 200 shot run 9.90

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