Whats cams to use.

[GPRD]

I have a z650 that I have had to bore out to 700cc with a wiseco psiton kit.
I was told fitting gpz750 cams would add more power then just standard cams.
My question is, would normal gt750 cams give a good power increase (maybe not to the same level as gpz), or would I might aswell just stick with the standard cams?
I don't know anything about lift and all the usual stuff that goes with it, so an idiots guide would be appreciated.
Cheers

[zed1015]

GT was a bit of a cookin motor but still booked at 125mph don't know if they are higher lift to the 650 cams.
GPZ is the obvious candidate for donating its cams thoiugh.
Whichever cams you use you need to look up the lift figures.

To keep things simple just go for the highest lift.

If you have the GT cams to compare then measure them at 90 deg to the lobe at their smallest diameter (taking a line straight through the camshafts axis) This is the base circle.
Then measure the longest dimension from the lobe tip to the base.
Subtract the smallest figure from the largest to get the amount of lift they give.
Don't just measure the longest dimension as this means nothing without the base circle.

[Pigford]

Also make sure the "base circle" is the true reading.... SOme cams have a "Quietening Ramp", so the BC ranges less than 180 degs, making it hard to measuer accurately

[kev edwards]

I have done the measurements as Zed1015 advised and the figures are
Z650 35.74 - 28.12 =7.62 GT750 36.28 - 28.32 = 7.96 giving an extra 0.34mm lift, the 650 and the gt 750 had about a 10bhp power difference, so using very basic maths and comparrisons you could increase your bhp, of course carbs would probably need re-jetting to gain full potential.

[zed1015]

I have done the measurements as Zed1015 advised and the figures are
Z650 35.74 - 28.12 =7.62 GT750 36.28 - 28.32 = 7.96 giving an extra 0.34mm lift, the 650 and the gt 750 had about a 10bhp power differnce, so using very basic maths and comparrisons you could increase your bhp, of course carbs would probably need re-jetting to gain full potential.

That .34 most likely won't give you that extra 10hp though as the carbs were also bigger but every little helps
Wouldn't do any harm to open up the head too while you're at it.
Go for it.
You will need to compensate for the GT cams larger base circle and go down on the shim sizes by that 0.20 difference.

[GPRD]

Thanks very much for your help and advice.
I'm going to check the GT cams out, and I'll be running pods and up jetting it, so hopefully the cams may add a bit more.