gpz cam swap

Just recently came across a set of 81-82 gpz1100 cams. I have heard people talk about them on here. Can I put them in my basically stock kz? And is it worth it?

jonarmstrong wrote: Just recently came across a set of 81-82 gpz1100 cams. I have heard people talk about them on here. Can I put them in my basically stock kz? And is it worth it?

I'm not certain, but weren't the early GPZ1100 81-82 cams identical to every cam used in thousands of J-engines made from 81-05? Isn't it just the GPZ1100 83-84 model years, the cams to get excited about?

Someone please back me up?

daveo wrote:

jonarmstrong wrote: Just recently came across a set of 81-82 gpz1100 cams. I have heard people talk about them on here. Can I put them in my basically stock kz? And is it worth it?

I'm not certain, but weren't the early GPZ1100 81-82 cams identical to every cam used in thousands of J-engines made from 81-05? Isn't it just the GPZ1100 83-84 model years, the cams to get excited about?

Someone please back me up?

+1 on the 1983/4 GPz cams. To expand, each model in the J series had a different grind, more or less. What was unique about the 1981/82 GPz1100 cams is that the intake and exhaust grind profiles were identical, but mounted differently in the cam sprockets.

83/84 Gpz1100 cams are the one to get but........... Keep in mind the is no provision for tachometer.

So they are the same thing I already have? Bummer! I have another J motor with a busted timing chain I am about to start a rebuild on. What cams should I be looking for to upgrade?

And my tach doesn't read off the cam. I have no wires to the top of head

jonarmstrong wrote: And my tach doesn't read off the cam. I have no wires to the top of head

Cams are either driven by cable off the exhaust cam (early KZs )
or off the ignition ( late KZs ).

The 81-82 GPZ cams are a less aggressive profile than the coveted 83-84's. They are more duration and lift than the earlier stock KZ cams. I have a thread documenting this with information from OMR. You will need new adapter cam gears from APE that allow the use of the different bolt pattern of the GPZ with the roller chain and 15 tooth crankshaft gear. I bought the 81-82 GPZ cams since they are cheaper and easier to come by, plus they are still a decent performance bump over stock.

FWIW,
Cory

I would also add that the valve springs are a different pressure for the GPZ than the LTD/ CSR/ Police/ Shaft drive cams.
I added some APE springs when I put in the GPZ cams in my LTD motor.

Here are the numbers I have on the cams in question.

One thing to note is that the 81 GPz 1100, 81-83 KZ 1000 J1-J3 and 82 KZ 1000 R1 are the only models to use different cams for intake and exhaust.

Another ting to note is that for the 83-84 (85?) GPz 1100s Kawasaki chose to switch from shim over to a shim under setup. I´m not really qualified to determine whether that is necessary or not when doing a swap, but if it is you will also need new buckets, shims and retainers.

Edit: Btw, if anyone has the lift and open/close numbers for the 12044-1027 cams please post them, same goes for the open/close numbers for the 12044-1057 cams (83> GPz 1100).


1982 KZ1100-A2, rated as 92 hp:

Intake (12044-1027):

Duration: 270 - Lift: Not exactly sure, but a little less than the 81 GPz.

Exhaust (12044-1027):

Duration: 270 - Lift: Not exactly sure, but a little less than the 81 GPz.

Used on:

KZ1000-K1 (LTD) (1981)
KZ1000-K2 (LTD) (1982)
KZ1000-M1 (CSR) (1981)
KZ1000-M2 (CSR) (1982)
KZ1000-P1 to P24 (Police 1000) (1982 - 2005)
KZ1100-A1 (Shaft) (1981)
KZ1100-A2 (Shaft) (1982)
KZ1100-A3 (Shaft) (1983)
KZ1100-D1 (Spectre) (1982)
KZ1100-D2 (Spectre) (1983)
KZ1100-L1 (LTD Shaft) (1983)
ZN1100-B1 (LTD Shaft) (1984)
ZN1100-B2 (LTD Shaft) (1985)



1981 KZ1100-B1 Gpz, rated as 102 hp:

Intake (12044-1031):

Duration: 280 - Lift: 8,4 mm (.330") - Open: 35 BTDC - Close: 65 ABDC

Exhaust (12044-1036):

Duration: 280 - Lift 8,8 mm (.346") - Open: 68 BBDC - Close: 32 ATDC

Used on:

KZ1000-J1 (1981)
KZ1000-J2 (1982)
KZ1000-J3 (1983)
KZ1000-R1 (Eddie Lawson Replica) (1982)
KZ1100-B1 (GPz) (1981)



1982 KZ1100-B2 GPz, rated as 109 hp:

Intake (12044-1037):

Duration: 288 - Lift: 8,8 mm (.346") - Open: 34 BTDC - Close 74 ABDC

Exhaust (12044-1037):

Duration: 288 - Lift: 8,8 mm (.346") - Open 72 BBDC - Close 36 ATDC

Used on:

KZ1000-R2 (Eddie Lawson Replica) (1983)
KZ1100-B2 (GPz) (1982)



1983/84 ZX1100-A1/A2 GPz, rated as 120 hp:

Intake (12044-1057):

Duration: 300 - Lift: 9,6 mm (.375")

Exhaust (12044-1057):

Duration: 300 - Lift: 9,6 mm (.375")

Used on:

ZX1100-A1 (GPz) (1983)
ZX1100-A2 (GPz) (1984)

Motor Head wrote: I would also add that the valve springs are a different pressure for the GPZ than the LTD/ CSR/ Police/ Shaft drive cams.

That is true for the 83 and later GPz 1100s, for the 81 and 82 GPz 1100s (B1 and B2) they're the same, 49078-1001 inner spring and 49078-1002 outer - fresh, upgraded valve springs can't really be a bad thing though..

So let me get this straight... The gpz cams I have are better than the stock kz cams I'm running but I'll have to get gears to make them work? I assume the bolt pattern on the gears is the difference :S Is there a possibility I'll have to re-jet my carbs as well? And according to OnkelB, I'm not sure which cams I have because they were presented to me as 81-82 gpz cams?!