1984 GPZ 1100 cam lobe hight

man-of-war wrote:
Zed do you own one of these bikes? You and Larry have lots of knowledge on them.

I have one or two :laugh:

Here's a couple


My everyday ride z1r.


My supercharged zed.


My current cafe project.


My slow burning 1428 supercharger Moriwaki project.



As for the oil cooler you could maybe find something off a newer sports bike to modify but i just buy an Earls,goodridge or mocal one (They are pretty much all the same)
A 10 or 13 row full width should be big enough.

Those are some nice rides Zed You do nice work!!!

M.O.W. when you break in that motor, don't drone along on the highway. Get out on some back roads where you can vary the RPM.

Zed as Larry said You do nice work!! those bikes look awesome...Where is the battery on the green supercharged zed ?



I like the front and rear suspension upgrade you did on your bikes,could something like that work on my 84 gpz 1100?

As the saying goes, the more you learn the less you know.

LarryC wrote: Those are some nice rides Zed You do nice work!!!

M.O.W. when you break in that motor, don't drone along on the highway. Get out on some back roads where you can vary the RPM.

man-of-war wrote: Zed as Larry said You do nice work!! those bikes look awesome...Where is the battery on the green supercharged zed ?

I like the front and rear suspension upgrade you did on your bikes,could something like that work on my 84 gpz 1100?

The battery on the supercharged is in the seat hump.
I squeezed a 9 amp in as i am not running a starter motor although a 14 amp gel would go in in it's side.

The cafe racer won't have a battery at all for actual running as i have a self generating CDI race ignition for that one
Here - www.electrexworld.co.uk/acatalog/STK-310.html

I have done suspension upgrades on gpz11's, it's just the same work as on any bike.
You really need access to a lathe at the very least(I have my own)as steering stems need machining or modifying and spacers turning for the swingarm and wheel alignment.

The possibilities are endless.

Suzuki arms are popular as they are usually slimmer at the pivot so just need a spacer and usually a sleeve for the pivot depending on how the job is tackled.
Front ends are more problematic as most modern forks are pretty short and will mess up the handling and drag the exhaust without extensions.
ZX9R-B usd's are a good choice (as fitted on the supercharged one)as they are fairly long.
On the std zx9 they protrude approx 50mm above the top yoke to mount the bars on so when fitted to the Z/GPZ you can drop them through for that extra length and either re-fit the bars under the top yoke or fit risers for normal high bars, renthals etc.

LarryC wrote: Those are some nice rides Zed You do nice work!!!

Thanks Larry, Much appeciated

I was very interested in your comment on another thread regarding the flow capabilities of the UNI head on a 1428 block.

I have just accuired a good UNI head for the Moriwaki project and could do with some actual proven porting advice/dimensions before i tackle it.

That is, of course if you wish to divulge ? :whistle:

Hi Zed or LarryC I got the head back from the shop today but the gaps have changed again could some one help with finding the correct shim for this head.I would have played around with it until I dialed it in but inorder to replace the shims for another I have to drive 1 and a half hours to the bike shop to exchange them.

# 1 INTAKE GAP= 0.55mm

---

SHIM=2.00mm
#2 INTAKE GAP= 0.40mm

---

SHIM=2.20mm
#3 INTAKE GAP= 0.30mm

---

SHIM=2.15mm
#4 INTAKE GAP= 0.40mm

---

SHIM =2.00mm

#1EXHAUST GAP=0.25mm

---

SHIM=2.00mm
#2EXHAUST GAP=0.30mm

---

SHIM=2.10mm
#3EXHAUST GAP=0.30mm

---

SHIM=2.10mm
#4EXHAUST GAP=0.40mm

---

SHIM=2.20mm

man-of-war wrote: Hi Zed or LarryC I got the head back from the shop today but the gaps have changed again could some one help with finding the correct shim for this head.I would have played around with it until I dialed it in but inorder to replace the shims for another I have to drive 1 and a half hours to the bike shop to exchange them.

# 1 INTAKE GAP= 0.55mm

---

SHIM=2.00mm = 240
#2 INTAKE GAP= 0.40mm

---

SHIM=2.20mm = 245
#3 INTAKE GAP= 0.30mm

---

SHIM=2.15mm = 230
#4 INTAKE GAP= 0.40mm

---

SHIM =2.00mm = 225

#1EXHAUST GAP=0.25mm

---

SHIM=2.00mm = 210
#2EXHAUST GAP=0.30mm

---

SHIM=2.10mm = 225
#3EXHAUST GAP=0.30mm

---

SHIM=2.10mm = 225
#4EXHAUST GAP=0.40mm

---

SHIM=2.20mm = 245

Above figures are with a gap aimed at the .15mm factory recommended maximum.

man-of-war wrote: Hi Zed or LarryC I got the head back from the shop today but the gaps have changed again could some one help with finding the correct shim for this head.I would have played around with it until I dialed it in but inorder to replace the shims for another I have to drive 1 and a half hours to the bike shop to exchange them.

# 1 INTAKE GAP= 0.55mm

---

SHIM=2.00mm
#2 INTAKE GAP= 0.40mm

---

SHIM=2.20mm
#3 INTAKE GAP= 0.30mm

---

SHIM=2.15mm
#4 INTAKE GAP= 0.40mm

---

SHIM =2.00mm

#1EXHAUST GAP=0.25mm

---

SHIM=2.00mm
#2EXHAUST GAP=0.30mm

---

SHIM=2.10mm
#3EXHAUST GAP=0.30mm

---

SHIM=2.10mm
#4EXHAUST GAP=0.40mm

---

SHIM=2.20mm

If those are your current shim sizes, you're running out of adjustment. The valves need to be tipped. This is common when an automotive machine shop does a valve job on heads for old Kawasaki motorcycles.

With shim on bottom retainers and buckets, there's a bit more complication to be considered when tipping valves. If it was a virgin head, then tipping the valves .010" - .020" is generally not an issue. Tipping them .010" will move you up about 5 shim sizes thicker.

Tip distance [top of stem to top of retainer cup] should not exceed the thickness of the thinnest shim or bucket to retainer contact can occur. That can lead to dislodged keepers and dropped valves.

Tipping the valves is easy BUT needs to be done on a valve machine or some grinder that tips them square. If the stem tips are not perpendicular to the stem, fractured shims can result.

Zed,

I don't know what you mean by a UNI head?

A KZ head, 900 / 1000

 is a BUNCH of work and valve deficient for a 1428 motor. What I do with them for a big block KZ is start with J 38.5 / 32 valves and resize them to 38 / 31. It's "sink city" to get your .185" minimum distance between the valves when seated. That's using stock seats.



J valves are .050" shorter than KZ so it gives you some working room. When finished, shoot for thick shim range if it's going to have serious cams and be pounded hard.



Porting wise, you won't make the intake port too big for a 1428 that you want to peak at 8000 - 9000 RPM.



All things considered, the best OEM head to start with is the late model GPz11 and use correct pistons. If you have Excel, I can give you a spreadsheet I made up to figure your installed height based on cam base circle and bucket thickness.

LarryC wrote: Zed,

I don't know what you mean by a UNI head?

A KZ head, 900 / 1000

 is a BUNCH of work and valve deficient for a 1428 motor. What I do with them for a big block KZ is start with J 38.5 / 32 valves and resize them to 38 / 31. It's "sink city" to get your .185" minimum distance between the valves when seated. That's using stock seats.



J valves are .050" shorter than KZ so it gives you some working room. When finished, shoot for thick shim range if it's going to have serious cams and be pounded hard.







Porting wise, you won't make the intake port too big for a 1428 that you want to peak at 8000 - 9000 RPM.



All things considered, the best OEM head to start with is the late model GPz11 and use correct pistons. If you have Excel, I can give you a spreadsheet I made up to figure your installed height based on cam base circle and bucket thickness.

Hi, By Uni i mean the Unitrack Gpz1100 twin swirl head.(Which is the later 83 on head)
I would just like some proven measurements/runner shapes for this head that work to get max flow out of it rather than just go the text book route and maybe not get full potential or over port which is so easy to do.
Currently i will be retaining the standard diameter valves.
Max diameter at the intake port mouth will be just touching 40mm to leave a good 2mm band for the boots to seat on.
All the rest of the engine work, valve trimming etc etc i can do with my eyes shut (That's how i make my money )
Regards, Rob.

zed1015 wrote:

LarryC wrote: Zed,

I don't know what you mean by a UNI head?

A KZ head, 900 / 1000

 is a BUNCH of work and valve deficient for a 1428 motor. What I do with them for a big block KZ is start with J 38.5 / 32 valves and resize them to 38 / 31. It's "sink city" to get your .185" minimum distance between the valves when seated. That's using stock seats.



J valves are .050" shorter than KZ so it gives you some working room. When finished, shoot for thick shim range if it's going to have serious cams and be pounded hard.







Porting wise, you won't make the intake port too big for a 1428 that you want to peak at 8000 - 9000 RPM.



All things considered, the best OEM head to start with is the late model GPz11 and use correct pistons. If you have Excel, I can give you a spreadsheet I made up to figure your installed height based on cam base circle and bucket thickness.

Hi, By Uni i mean the Unitrack Gpz1100 twin swirl head.(Which is the later 83 on head)
I would just like some proven measurements/runner shapes for this head that work to get max flow out of it rather than just go the text book route and maybe not get full potential or over port which is so easy to do.
Currently i will be retaining the standard diameter valves.
Max diameter at the intake port mouth will be just touching 40mm to leave a good 2mm band for the boots to seat on.
All the rest of the engine work, valve trimming etc etc i can do with my eyes shut (That's how i make my money )
Regards, Rob.

Got it I should have realized that's what you meant. Makes perfect sense now...

You're in pretty good shape with that head as far as port cross sectional area available to work with. Still a bit valve deficient even with 39's on the intake side but that's the head you want to be using.

I figured you'd be in a position to do the machining based on your projects. Here's some porting tips for you.

Where the bowl and the runner meet is the area that makes HP. Make that at least 100% of the valve size. D port the intakes.

90 - 91 % on the throats [seat opening] intake side. 89 - 90 % on the exhaust.

Find some exhaust gaskets that don't poke down below the edge of the exhaust port roof after they crush. OEM copper exhaust gaskets often do that. I see that all the time.

The exhaust port floor is dead so don't put time into that except for blending. Hook up a shop vac on exhaust and blow through your exhaust ports. You'll fab up something without my explaining it....I'm sure of that.

Make a U Tube water manometer with a probe connected to it. Use it to probe the exhaust port. You'll see where the air is moving and where it's not. Give it area where it naturally wants to go

A guy with your abilities could build a flow bench relatively easily and make good use of it. I'll help you get that project off the ground with some good information and links if you decide to

Bit unsure what you mean by 'D' porting the intakes ?

'D' porting the exhaust(leaving the port floor relatively untouched)is standard practice.