270Deg cam and turbo


Wrench Pro
South Africa
i have a Astra 160ie and i'm in the process of turbo charging it, it currently has a 270Deg cam in it, is it ok for me to keep that cam in or will i need to get a standard cam, 270 is a very mild cam so i'm not sure if i will get overlap or not with it.

Thanks a mill.
If this was my project I'd look at the cam numbers on the Turbo derivatives.
To start plot the Cam profile as a function of crank position on a full 720 deg cycle.
The US Comp Cams Website have an cam selector which will plot their cams has an basic engine simulator.
This link will let you download it after first registering (Its free!)
To compare cams you need 4 timing positions
Intake open (ivo)
Intake close (ivc)
Exhaust open (evo)
Exhaust close (evc)
the difference between evo which occurs before ivc and defines the cam overlap
You will also need the intake exhaust durations, lift, and lifter ratio and the profile.

Many people regard cams a Trade secret so will not give out these numbers.
The IVC and EVO combine to define the dynamic Compression ratio (which the actual CR seen in use).
Assuning it gives you some cams use the timing values to find one fits your use from Piper or Kent.
I am not associated wiuth company but have used this tool which is good starting point for cams

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