GS1000 head swap?

hardr0ck68 wrote:

PLUMMEN wrote:

check with hardrock,he can tell you where to cut it

Hey man, your right! I am sure if you looked hard enough you could find a head that fits close enough to make it work. Anything can be done with enough time/money/skill (I have the time and the money comes and goes, the skill however is all provided by a friend )

As for the "it's not a KZ anymore" folks, Tell that to those guys running vortec heads they don't strip the kz badges off of their bikes, at least the head I am working with is a Kawasaki!

So far I have $250 invested in parts; but I am still a long ways out. I bet it could be done for less then $1000 sans labor. I won't know how much HP I bought for all this until I get it to a dyno, but its all about giving the finger to people who say it shouldn't be done!

i just said you know where to cut it,thats what you did to make yours fit a 750 didnt isnt it?

Correct, the block and head were both cut, and will be welded back together when the time comes. The cam's will also need to be cut and a coller machined up to lengthen them.

TG:
No big progress to report, but the project is far from dead. I just picked up some more parts for it, a set of pistons from a 1995 zx750, they are 3mm larger than the 90zx750 and they will require machining to fit the kz rods... they should put the final displacement at just under 900cc's. I doubt this thing will be done in time for spring, but thats cool, like I said I have time.

While you're at it why not open up pairs of cylinders, use oval pistons, and plug in 8 valves per cylinder. I would love to see the HP and torque of a KZ1000 two cylinder eight valve per cylinder monster. Kinda like the front half of the engine in the link:

Engine

I remember that Honda motor. NS750 as I recall. That's ancient but it was pretty cool at the time. Wonder what a top end rebuild costs ? :laugh:

KT, if you want some cheap power for your bike, find some 83 GPz1100 cams and bolt them to your sprockets. They'll drop right in.

Larry C

back in the late 70's the 8-valve GS1000's came on the scene, they started to win drag races fairly quickly. Their advantage was a cylinder head running larger valves than the KZ1000. The KZ1000 head was just a Z1 900 head on a 1000 bore - so the combustion chamber of the Z1 /kz900/KZ1000 (thru 80) heads all have a hemi combusion chamber sized for 66mm bore rather than 70mm bore.. This meant the valves were closer together.

I remember GS1000 heads being transplanted on KZ1000 engines up through the early 80's when the J engine appeared (which had a better head than the GS). The cylinder stud pattern on the GS1000 head is identical to the Z1/KZ head, the bore spacing is identical (amazing Suzuki could come up with exactly the same dimensions huh?) - all you need to do is some custom work for the top idler. I had bought one of these heads 7-8 years ago in a batch of parts - although it was badly damaged from a dropped valve, it was interesting to see how little modification it really needed to work.

MMM...TURBO!

Jeff.Saunders wrote:

back in the late 70's the 8-valve GS1000's came on the scene, they started to win drag races fairly quickly. Their advantage was a cylinder head running larger valves than the KZ1000. The KZ1000 head was just a Z1 900 head on a 1000 bore - so the combustion chamber of the Z1 /kz900/KZ1000 (thru 80) heads all have a hemi combusion chamber sized for 66mm bore rather than 70mm bore.. This meant the valves were closer together.

I remember GS1000 heads being transplanted on KZ1000 engines up through the early 80's when the J engine appeared (which had a better head than the GS). The cylinder stud pattern on the GS1000 head is identical to the Z1/KZ head, the bore spacing is identical (amazing Suzuki could come up with exactly the same dimensions huh?) - all you need to do is some custom work for the top idler. I had bought one of these heads 7-8 years ago in a batch of parts - although it was badly damaged from a dropped valve, it was interesting to see how little modification it really needed to work.

I'm going to start porting a GS1000 head next week. I'll post up some photos comparing it to the KZ, J & 83 GPz11 heads...

Larry
let us know how it stacks up against the 83/84 GPZ1100 head.

larrycavan wrote:

Jeff.Saunders wrote:

back in the late 70's the 8-valve GS1000's came on the scene, they started to win drag races fairly quickly. Their advantage was a cylinder head running larger valves than the KZ1000. The KZ1000 head was just a Z1 900 head on a 1000 bore - so the combustion chamber of the Z1 /kz900/KZ1000 (thru 80) heads all have a hemi combusion chamber sized for 66mm bore rather than 70mm bore.. This meant the valves were closer together.

I remember GS1000 heads being transplanted on KZ1000 engines up through the early 80's when the J engine appeared (which had a better head than the GS). The cylinder stud pattern on the GS1000 head is identical to the Z1/KZ head, the bore spacing is identical (amazing Suzuki could come up with exactly the same dimensions huh?) - all you need to do is some custom work for the top idler. I had bought one of these heads 7-8 years ago in a batch of parts - although it was badly damaged from a dropped valve, it was interesting to see how little modification it really needed to work.

I'm going to start porting a GS1000 head next week. I'll post up some photos comparing it to the KZ, J & 83 GPz11 heads...

Can you compare it to an 81 K model too... FOR ME?
It would rock, you can post the picks on here if your not already planning on making a new thread!!

Kitten Tooth wrote:

larrycavan wrote:

Jeff.Saunders wrote:

back in the late 70's the 8-valve GS1000's came on the scene, they started to win drag races fairly quickly. Their advantage was a cylinder head running larger valves than the KZ1000. The KZ1000 head was just a Z1 900 head on a 1000 bore - so the combustion chamber of the Z1 /kz900/KZ1000 (thru 80) heads all have a hemi combusion chamber sized for 66mm bore rather than 70mm bore.. This meant the valves were closer together.

I remember GS1000 heads being transplanted on KZ1000 engines up through the early 80's when the J engine appeared (which had a better head than the GS). The cylinder stud pattern on the GS1000 head is identical to the Z1/KZ head, the bore spacing is identical (amazing Suzuki could come up with exactly the same dimensions huh?) - all you need to do is some custom work for the top idler. I had bought one of these heads 7-8 years ago in a batch of parts - although it was badly damaged from a dropped valve, it was interesting to see how little modification it really needed to work.

I'm going to start porting a GS1000 head next week. I'll post up some photos comparing it to the KZ, J & 83 GPz11 heads...

Can you compare it to an 81 K model too... FOR ME?
It would rock, you can post the picks on here if your not already planning on making a new thread!!

KT... flow wise, both the GS1000 head and your K model J head flow about the same.

There were 2 different GS1000 2 valve type heads, just like there were 2 differnt base model Kawasaki heads.

Early heads had small port runners. Those types were designed to run the smaller VM Mikuni mechanical throttle slide carburetors [26mm & 28mm].

Later heads had the larger port runners because at that time, all the manufacturers were moving to CV type carburetors. BS34 Mikunis, etc.

Where all the uninformed people went wrong is they went gaga over the fact that the later heads had bigger ports. OH BOY!!! That must be way better....it's bigger. Bigger is always better :laugh: Well, it's just not that simple.

For the size of the port runners and the increase in valve sizes, the later heads were not major improvements to the flow.

What makes a 2 valve cylinder head pick up flow is not nearly as tied to the size of the port runner as most guys think it is

Here are the 3 things that will make a night & day difference in your bike's performance. I don't think you have enough riding experience under your belt to be ready for them just yet..

Cams, Porting, Carburetors.

Here's the economical approach to doing it.

Scope Ebay for cams and a rack of RS34 Mikunis. I see RS34's on there for great prices quite often.'

83 - 85 GPz11 cams

88CFM through your J head.

When you reach a level where you can really handle the HP upgrade, you holler and I'll port your head for free Kid

Larry C

larrycavan wrote:

I remember that Honda motor. NS750 as I recall. That's ancient but it was pretty cool at the time. Wonder what a top end rebuild costs ? :laugh:

KT, if you want some cheap power for your bike, find some 83 GPz1100 cams and bolt them to your sprockets. They'll drop right in.

Larry C

Hey, do i have to change my valve springs or clearances or anything like that? Or, can i just bolt the new cams in and set everything else to stock specifications? I heard with bigger cams, you needed higher tension springs..

ill take you up on that offer probably this summer if your cool with that.. Thats really cool of you to offer that man. Ill look around Ebay for them carburetors. My 1000 is kind of a test bike:) We make adjustments, if they're good, my dad makes the same changes on his 1000 and we ride on. My dad and i both thank you for the info on the carbs and the cams too. Ill PM you when the time comes:D THANK YOU!!!!