Cam Timing

[cammmy 1]

Hi Guys

 

Does anyone know of a good article about cam timing or know about it themselves (Peter? )

 

I'm not sure if I've brought this up before but I would like to see if I can increase the high end torque. I am willing to sacrifice some low RPM tractability.

 

I don't necessarily want to shift the curve up (as I have previously posted) but would like to increase the high RPM torque and power. I guess I would like for power to peak at about 7,100 - 7,200.

 

Could I look at adjusting one of the cams, 1-tooth or so to increase overlap? Would I want to adjust the inlet cam or the exhaust cam? Would I want to advance or retard?

 

How far can I go before risking valve to piston contact?

 

As my motor is coming out to be re-shelled I figure it's a good time to swap the oil pump sprocket and chain for the XU10 units I have. This involves taking the cambelt off (?) so figured it a good time to look at doing this.

 

Ta

Cam

[welshpug 1,626]

would it not be better to improve mid range power, after all that's what makes a car faster and easier top drive fast, not necessarily the big headline figure

[cammmy 1]

I'm not looking for a big hp figure with nothing underneath it. Just looking to move the torque curve up to where I will be spending the most time. Would like it to drop off later and = a bit more power between 4,500 and 7,400.

 

I would need some vernier pulleys to do this anyway.

 

It's not a road car anymore so I'm not looking for 5th gear overtaking ability :-)

 

Edited September 7, 2010 by cammmy

[cammmy 1]

Right. Getting a sweet deal on some vernier pulleys so they have been ordered.

 

I have read that advancing the inlet cam pushes the torque curve upwards. I would have thought retarding it so the valves close later would have that effect?

 

Or is it due to the increased scavanging of opening the valves earlier and increasing overlap?

 

Wasn't planning on getting these until I had new cams but the price was right.

[petert1345402284 0]

http://www.billzilla.org/engvariable.html

 

and

 

http://www.billzilla.org/engvalve.htm

[cammmy 1]

Cheers Peter, will give them a read.

 

Also, I'm wanting to buy stuff from you so a reply to my price request email would be good