Ricardo Valve lift Profile

[ritwikdas18]

How do you get the valve lift profile for your engine for inputting it in Ricardo?
I have the following data as of now:
Intake Valve:Opens at 1 mm lift 20 degrees BTDC
Closes at 1 mm lift 35 degrees ABDC
Exhaust Valve :Opens at 1 mm lift 40 degrees BBDC
Closes at 1 mm lift 0 degrees TDC

[jd74914]

Hi Ritwik,

You need to measure the profile off your engine and use that as an input.

There is a thread on this page called "Problem with Measuring Camshaft Profile" which has some good instructions for doing this (and a link to an awesome forum post with more details). Just search for the thread; posting a link used to take a while to get approved.

[Jonny Rochester]

From the data given, you don't know exactly when the valve opens and closes as your positions are given at 1mm lift, and you don't know the exact duration. But what you can work out precisely is your lobe center positions. (I have no idea what Ricardo is, or what it needs).

Intake lobe center: ((20 + 180 +35) / 2 ) - 20) = 97.5 degrees

Exhaust lobe center: ((40 + 180 + 0) /2 ) - 0) = 110 degrees

So now you know your exact lobe centers (need to visualise this).

If you somehow find what your total valve opening durations are (from open to closed valve, not at 1mm), then you can work backwards and use these lobe centers to find open and close positions.

[Jonny Rochester]

Your intake duration is more than 235 degrees, but we can only guess how much more.
Your exhaust duration is more than 220 degrees, but we can only guess how much more.

Glancing at these numbers, it seams your exhaust cam is conservative/normal, and your intake cam is more sporty. (Non engineering terms, please don't shoot me!)