Oversize Piston Kits...

APE Jay wrote:

If it is a 1000 block, 1260 is the limit. Keep the cylinder pressure down with overlap, and you should be OK.
Here is your piston selection. kzzone.com/pistons.html

How does over lap keep the pressure down? Is it possible that this statement is incorrect?:woohoo:

nads.com wrote:

APE Jay wrote:

If it is a 1000 block, 1260 is the limit. Keep the cylinder pressure down with overlap, and you should be OK.
Here is your piston selection. kzzone.com/pistons.html

How does over lap keep the pressure down? Is it possible that this statement is incorrect?:woohoo:

I believe that the overlap allows some of the intake charge to escape before both valves are closed. This way there is less fuel/air mix to compress = less pressure.

beefsquasher wrote:

I don't understand how a thin wall causes overheating. It's all about heat transfer. I'm not just using the mass of the block to absorb the heat, I'm using it to transfer heat to the fins. Where am I thinking wrong on this?

Why are buttons better than clips? I have never but NEVER seen a clip come out that was new when installed and installed properly.

-Dave

Think of it like Wiring, Too small of a wire and it wont carry much amprage, same with the cylinders not much metal to carry the heat out to the cooling fins.

beefsquasher wrote:

Now that I finally have my bike running good and leak free, I'm lining up some more upgrades for this winter.

First on the list is some bigger pistons. I have heard that for street use, a big block is a no-no as there are no cooling passages between the cylinders which leads to overheating. Therefore i have decided on 1197cc which i think is the biggest you can get out of the stock block.

It looks like I have 2 choices: MTC or Wiseco. Which is better and where is the best place to get a good price on these babies?

Other coming upgrades: dry-blocking, oil cooler, welded crank, better ignition system (with a digital advance - I'm fed up with the mechanical advance).

-Dave

1197 kit works just fine on the street with a resleeved stock block.

Are you going drag racing or looking for a street motor that you don't have to downshift to pass cars ?

Pick the cam wisely or you'll end up with a bike that's not nearly as much fun to ride as you had hoped for....

larrycavan wrote:

beefsquasher wrote:

Now that I finally have my bike running good and leak free, I'm lining up some more upgrades for this winter.

First on the list is some bigger pistons. I have heard that for street use, a big block is a no-no as there are no cooling passages between the cylinders which leads to overheating. Therefore i have decided on 1197cc which i think is the biggest you can get out of the stock block.

It looks like I have 2 choices: MTC or Wiseco. Which is better and where is the best place to get a good price on these babies?

Other coming upgrades: dry-blocking, oil cooler, welded crank, better ignition system (with a digital advance - I'm fed up with the mechanical advance).

-Dave

1197 kit works just fine on the street with a resleeved stock block.

Are you going drag racing or looking for a street motor that you don't have to downshift to pass cars ?

Pick the cam wisely or you'll end up with a bike that's not nearly as much fun to ride as you had hoped for....

Isn't it true that the cam can do only so much, if you don't have the ports to deliver the air to it? I'm not sure if a stock or almost stock head could deliver even enough air to supply .400 lift cams.
Hay Larry, post a good copy of that beautiful graph you have on your sight. It's a bit small for any of us to post it.

beefsquasher wrote:

I don't understand how a thin wall causes overheating. It's all about heat transfer. I'm not just using the mass of the block to absorb the heat, I'm using it to transfer heat to the fins. Where am I thinking wrong on this?

Why are buttons better than clips? I have never but NEVER seen a clip come out that was new when installed and installed properly.

-Dave

If you have to ask, than i would do some research before you do anything that you will be sorry about later. Many of us have been doing this for decades and are offering the wisdom of our experience. Most anything will run fine, but for how long in what situations. a shop will sell you on anything, but will they refund you the money if you are not happy? Or replace the components that go bad? I

---

Don't think so. Choose wisely and do research before you act. I was an aircraft mechanic for many years and have worked on air cooled motors much bigger and more sophisticated than these. One thing you do not do, and that is to bore out a aircraft cylinder, because it will overheat.

otakar wrote:

You will have just as many heat problems if not more with the 1200 kit as you would have with a big-block. You will be at the extremes on both the sleeve wall thickness and the block thickness also. There wont be enough metal there to dissipate the heat for any kind of stop and go traffic. You will be fine on the highway but if you ketch any kind of traffic you will be in trouble. I like the MTC pistons because they use and come with buttons and not clips. If you use the Wiseco pistons they are also good but I would use MTC buttons with them.

the 1197 in a stock block will run much cooler than a bigblock motor due to no cooling passages between the sleeves on the bigblock,my 1327 is not ridable on hot days around town.
1197 with the right sleeves has plenty of meat in the cylinders,i dont agree with the 1260 in a stock block but some people seem to like it.

The only problem 1260 stock blocks had was everyone used the Suzuki 1260 sleeve, which is slightly too big for a Kawasaki and it would wind up being a leaker.

We did a Kawasaki specific 1260 liner, and it works great. No more heat that an 1197.

Some performance data to ponder ....

1327cc, 88CFM C&W Head, Worn the hell out Andrews 8x cams, Street compression pistons, head shaved a little.

Heavy bike, car tire he doesn't neet, 170 lb rider, guy can't ride it very well yet.....6.04 - 112MPH

1135 J, Guessing 90CFM head based on who ported it, small tire, GPz11 cams, 13:1 compression, old school chassis, lard ass 260lb rider.....6.34...forget MPH at the moment

Same bike with light rider....6.18

Both bikes 38 Trons

Point is simple....COMPRESSION makes bikes accelerate and you don't need big ass cams in a KZ or J for it to run fairly well.

PS....ZX14 with Commander, Brocks Pipe, Arm and kid that can ride.... 5.80's - 124MPH time after time after time after time..... Then he rides it home :laugh:

larrycavan wrote:

Some performance data to ponder ....

1327cc, 88CFM C&W Head, Worn the hell out Andrews 8x cams, Street compression pistons, head shaved a little.

Heavy bike, car tire he doesn't neet, 170 lb rider, guy can't ride it very well yet.....6.04 - 112MPH

1135 J, Guessing 90CFM head based on who ported it, small tire, GPz11 cams, 13:1 compression, old school chassis, lard ass 260lb rider.....6.34...forget MPH at the moment

Same bike with light rider....6.18

Both bikes 38 Trons

Point is simple....COMPRESSION makes bikes accelerate and you don't need big ass cams in a KZ or J for it to run fairly well.

PS....ZX14 with Commander, Brocks Pipe, Arm and kid that can ride.... 5.80's - 124MPH time after time after time after time..... Then he rides it home :laugh:

yeah but it looks like every other plastic missile! :laugh:

PLUMMEN wrote:

the 1197 in a stock block will run much cooler than a bigblock motor due to no cooling passages between the sleeves on the bigblock,my 1327 is not ridable on hot days around town.
1197 with the right sleeves has plenty of meat in the cylinders,i dont agree with the 1260 in a stock block but some people seem to like it.

If both Larry and Plummen say it, I believe it...

larrycavan wrote:

Some performance data to ponder ....

1327cc, 88CFM C&W Head, Worn the hell out Andrews 8x cams, Street compression pistons, head shaved a little.

Heavy bike, car tire he doesn't neet, 170 lb rider, guy can't ride it very well yet.....6.04 - 112MPH

1135 J, Guessing 90CFM head based on who ported it, small tire, GPz11 cams, 13:1 compression, old school chassis, lard ass 260lb rider.....6.34...forget MPH at the moment

Same bike with light rider....6.18

Both bikes 38 Trons

Point is simple....COMPRESSION makes bikes accelerate and you don't need big ass cams in a KZ or J for it to run fairly well.

PS....ZX14 with Commander, Brocks Pipe, Arm and kid that can ride.... 5.80's - 124MPH time after time after time after time..... Then he rides it home :laugh:

i know of a 1327 in a stock 80ltd chassis with a 2" over arm lowered into the weeds with around 11:1 compression 410ish cams,head ported by a mad plumber with an ancient set of 33s that runs a best of 6.18 with a 5.5 tire and no bar with a 200 lb plumber laying over the bars hoping for the best,with a lock up clutch i think it will run a 6.10 on a good day