TOPIC:

Has anyone installed 1983 GPZ1100 camshafts in a 1982 KZ1100 (stock) engine, without having to modify the engine in any way. Just wondering if I'd run into problems, and if minimal performance gains would make it worth doing?

If other cams would be better, what should I look for? Again, I do not wish to make any other changes to the motor, which runs strong now. I'm not looking to do anything radical...

They will bolt right in however I doubt you will feel any difference in performance.

I had that in my lawson rep: 17mm GPZ11 B motor and 300 degree zx cams. It was stupid fast...like a gpz550 on steroids.

Not a touring bike tune, and lacking in bottom end, but it had such a crazy top end power band it really reminded me of the gpz550 tune - just crazy fast.
It had shim under bucket head and some light head work.

Disclaimer-don't quote me on GPz11's love them but my knowledge is minimal.

baldy110 wrote: They will bolt right in however I doubt you will feel any difference in performance.

Will the difference between the lobe designs allow more fuel/air into the cylinders, and increase compression to some degree?

The 83 GPZ 1100 cams are different than a set of 82's. They have a different profile for the iN and EX, where the earlier cams where the same IN and EX. I have a set of the 83's in my bike. Have swapped back to the stock cams, and there is quite a gain in power with the 83 GPZ cams. A loss of vacuum signal at Idle, a slight loss in low end torque below 2500 RPM, and with Stock BS34 CV style carbs I found it very hard to tune even with the stock airbox. So I went with RS34 carbs.
Also when changing cams, I recommend you go with a new set of springs. You will find the 83 GPZ valve springs are a different part # from the stock LTD/ CSR/ Police etc springs. I bought a set of APE valve springs, for the increased lift, and the stock springs were 30 years old!

Longer duration cams yes, maybe higher lift I think too ,also the late gpz11 I think had bigger valves.

Better breathing=more volumetric efficiency which will increase compression pressure - but only when ragging it. It works the opposite at low rpm...hence mild cams give better low end.

The 120 bhp xz1100 was a z900 motor taken to the limit, 150 percent over the 82 bhp z900.

Motor Head wrote: Also when changing cams, I recommend you go with a new set of springs. You will find the 83 GPZ valve springs are a different part # from the stock LTD/ CSR/ Police etc springs. I bought a set of APE valve springs, for the increased lift, and the stock springs were 30 years old!

Changing the valve springs would necessitate removing the head, correct?
I'd like to avoid that, at this point.

wow!

daveo wrote:

Motor Head wrote: Also when changing cams, I recommend you go with a new set of springs. You will find the 83 GPZ valve springs are a different part # from the stock LTD/ CSR/ Police etc springs. I bought a set of APE valve springs, for the increased lift, and the stock springs were 30 years old!

Changing the valve springs would necessitate removing the head, correct?
I'd like to avoid that, at this point.

While it may be best to remove the head, as the vales/ guides/ seats may need attention. It is not necessary for replacing the springs or valve stem oil seals.
If you already have a oil leak at the cam tunnel, or if you do a Leak Down Test and find leaky valves. Then pull the head. If compression and leak down test are good. You can replace the springs and stem seals with out pulling the head.