21 replies to this topic

[Spider]

Cheers - a bit far for me to attend!

 

While I am chewing on it, I'll say that from my own experience, while there are a number of camshaft factors that will greatly change it's characteristics, the biggest factors I've found as to when it comes to tractability or when 'it comes on the cam' is overlap and valve closing angle. It is this last factor that is allows the engine to come on sooner or later when the cam to crank angle are changed (ie, the angle that the cam is timed in at). I'm not disagreeing while what you've said though, just chewing it over.

[ACDodd]

The problem with angle, It makes no relation to valve movement. Overlap and overlap lift are 2 different things. You can have 2 cams with the same duration and overlap. The one with less overlap lift will be more drivable.

Ac

[Mini Manannán]

I am almost completely bamboozled.  Great stuff to read up on though you two

[Spider]

Cheers - a bit far for me to attend!

 

While I am chewing on it, I'll say that from my own experience, while there are a number of camshaft factors that will greatly change it's characteristics, the biggest factors I've found as to when it comes to tractability or when 'it comes on the cam' is overlap and valve closing angle. It is this last factor that is allows the engine to come on sooner or later when the cam to crank angle are changed (ie, the angle that the cam is timed in at). I'm not disagreeing while what you've said though, just chewing it over.

 

Oh and this ^ is why I no longer go by static CRs but moved to Dynamic CRs.

 

The problem with angle, It makes no relation to valve movement. Overlap and overlap lift are 2 different things. You can have 2 cams with the same duration and overlap. The one with less overlap lift will be more drivable.

Ac

 

Yes, my wordy. I map the profiles as you can have two cams, with the same 'angles' but quite different characteristic. The angles alone don't give us lobe profile.

 

 

I am almost completely bamboozled.  Great stuff to read up on though you two

 

Yeah, me too!

[carbon]

If you have been bought up on the duration rates a cam thing what you read from me will make little sense. Its one of the reasons I run 1 day cam workshops to enlighten those who have interest.

AC

 

AC - when's your next cam workshop?

[ACDodd]

No plan, but if someone wants to get upto six people together I can sort one out. I am based in Salisbury.

Ac

[mikal]

Thank you AC and everyone for your replies.

My understanding of camshaft theory has improved! I'm now thinking of retaining the camshaft, going to higher lift rockers (1.4's?) and getting the car dynotuned and see what I end up with. I want to retain most of it's low down torque and ideally improve its 0-60 mph performance.

 

Cheers

 

Mikal