Building an 1100

  • Thread starter Thread starter Rod Nock
  • Start date Start date
Great information. OK, how about this: If I used a ZX intake cam (1mm higher lift) with the ZG cam sprocket to retain the 37.5 deg intake opening event (intake duration now 290 degrees), and retained the stock ZG cam and timing (8.3mm lift, 275 degree duration, would I improve mid-range even further than with stock ZG intake cams?
 
The sprockets are all the same. Decide whether you want more top end or low end and choose the pair of cams that work to together with the rest of the system. Mixing the two won't give the best of both worlds.

ZG cams are better for street but if you don't mind keeping the revs up and downshifting more often, the ZX cams have more to offer. High lift, long duration, retarded timing and plenty of overlap work together with free breathing intake and exhaust systems. OTOH, small diameter headers and long inlet tracts work together with mild cams. Too much overlap kills low speed acceleration. Too little overlap will kill top end but at low speeds (where street bikes run most of the time), acceleration and carburetion will be great.

Generally, mild cams give best all around street performance and are easier to tune but if you want to be the fastest with hot cams and a free breathing intake and exhaust system, you have to expect terrible fuel mileage and poor low speed performance. Most OEM street bike cams are slightly advanced which doesn't sacrifice high or low speed performance as much as changing lift, duration or ovrlap does.

Fortunately, a 1000 cc bike already makes good low end torque so hot cams won't force you to keep the revs up for good acceleration like it would with a small bike. The ZL600 is a real turd at low revs so the advanced timing helps. Run the ZX cams if you're going to remove all the other restrictions in the system. Otherwise, your cams will be a bottleneck up top and the higher flowing intake and exhaust systems will kill power down low.
 
Again, great information. I checked the cams specs for the ZZR1100. They are 280/275, .388" lift for a 76mm bore/58mm stroke 1052cc 11:1cr engine. I think I will get the ZX intake cam reground to 280 deg with stock .366" lift with a stock 275 degree exhaust cam for my 75.5 bore/58mm stroke 1040cc 11:1 cr engine. I know that comparing the exterior intake and exhaust side plumbing are apples to oranges in this case, but I am looking for torque in the mid-70's ft-lbs range.
 
Where do you want that 70 ft-lb? Down low takes away peak HP. Up high takes away low end grunt. You may or may not get both depending on the torque curve.
 
So, here is my '95 Ducati Monster 900 with a 944 kit and 41mm FCR smoothbores So pleasing to ride! I hope to get the peak torque somewhere at 5500 -upload_2020-12-22_17-53-38.png 6000rpm, but as broad and flat as possible.
 
My problem with attempting to modify a driveshaft engine to get better acceleration and a higher top speed, which is what we're after, AND do it efficiently and relibly is that it would be easier and better to just adapt to a chain or belt drive. At least 15ish% more RWTQ throughout the powerband from an otherwise completely stock bike and room left for more power with future engine mods. Not to mention a small weight reduction.

These are just my personal feelings about my ZL600A1 museum piece. I think it would be cool to mod the frame to accept an OEM swingarm from some other Kawasaki. I was going to cafe it but I bought a used Zero FX for that.
 
You are so right. I just wish I knew which swing arm would fit in with as few (and futile) further modifications as necessary.
 
Comparing a twin to an inline four isn't really fair. In that dyno chart you can see where carburetion was affected under load at low RPM. A big twin naturally has good torque down lower but the Ducati is tuned for top end. My 950 air-cooled V-twin Yamaha puts out 50 - 60 ft-lbs from 1500 - 3000 where the Ducati is virtually non-responsive. Of course, I'm only making about 55 HP and EFI helps but there are other advantages to not being tuned for more HP than you need. Cheaper bike, better fuel mileage, cheaper gas (low octane), lower maintenance, less complexity, more relaxed ride.

An inline four is best for making higher HP because they can rev higher but having more cylinders doesn't mean it can't make good torque instead. The Gold Wing is a good example of that.

7VAYLYLP4RFSZKANPMX77BY7OM.jpg
 
Just relooking Rod Nock's original post, he said he was getting 2 mm overbore with ZX10 rods and ZZR1100 pistons. The Kawasaki Service Manual states max overbore is .5mm. With 2mm overbore, aren't you getting fairly thin cylinder walls?
 
:hello: WISECO says 1 mm over pistons are fine on inline 4 cyns and 2 mm on one lungers. A mod called 7 th gear is online https://sites.google.com/site/shoodabenengineering/7th-gear-unit or you can use the bevel gear from a ZG 1000 motor. It adds 2 teeth acting like a larger sprocket on the front of a chain driven bike. Also if you use a tranny from a ZG 1000 first and second gears are lower and sixth gear is higher than the ZL9/10.
 
Last edited:
OK, I totally missed your point. If "WISECO says 1 mm over pistons are fine on inline 4 cyns" why do they sell 1.5mm overbore pistons?
 
:hello: I ment to say 1.5 mm. When a cyn is bored only half of the cyn walls are bored out for an oversized piston. Some cyn can be bored out up to 4 mm such as in a air cooled motor because the cyn are much thicker.
 
Last edited:
Anyone know if a ZRX1100/1200 engine head will fit on a ZL/ZG/ZX block?
 
Oops, sorry...I should have been more specific. I have a bored ZG block using 76mm ZX11 pistons (1052cc). As the block is already at 76mm bore using ZX-11 pistons, will a ZRX head mate to the bored ZG1000 block without drama?
 
OK, so this passage is what I am trying to confirm (from ZRXocboard.com): "Kawasaki were very modular in their engine designs and the family of motors share an awful lot of parts although there are some slight changes over the years. The GPZ900R is the grandaddy of the family. The GPZ1000RX came next and shares stroke with 900R, GTR1000 came from this and ZL1000 came from this. ZX10 came next same stroke different head design, ZZR1100 developed from this motor, ZRX1100 and GPZ1100 same motor different head and side casings and sump, then came the ZZR1200 and ZRX1200 which are a longer 59mm stroke and use an ally plated cylinder assembly instead of steel liners. All the steel linered motors are mix and match versions of each other and as such it's possible to fit parts from them to make a hybrid motor as did a lot of grass track sidecar racers, using ZX10 motors with side draft heads fitted."
 
No, I am asking if it's possible. Moreover, I want to know if i can put a ZRX-1100 block and head on a C-10 case and use the C-10 conrods with a Zx11 or Zx12 piston. If so, one could go up to 1102cc with big bore ZX12 pistons using stock C-10 bottom end and conrods, for a 78x58 bore/stroke.
 
You must log in or register to reply here.
Back
Top