big bore - reliability?

i'm looking at taking my kz and buying the 1395cc kit from kzzone - anyone done this to a motor? are there any reliablility issues?

The quality of the aftermarket piston are higher than the ART castings that came in the KZ. We do not see these worn out. If one ever comes in for repair, it is because a valve fell in the motor, or something like that that has nothing to do with the piston kit.

Jay

That size is good for drag racing but not on the street. You'll have overheating issues.....i'd go with a 1075 and even then you will probably want to weld the crank & under cut the trans.

too much for the street, even at a mild compression it will overheat and the plugs will glow red hot and it will miss and preignite.

i run a 1170 and it almost overheats, keep the motor on a stock block and not a big block and you should be fine.

Does ape need to re-cast their big block in a diffenrent manner? Can the fins be made longer with cutout areas where the bike frame is too close? Wonder why they did'nt do that. And why they hav'nt changed that. This is not directly related to your question, but I have to wonder if alot of heat is trapped in the engine (the almighty 4-1 header )due to the back pressure at the collector. Four pipes into one you know. I had my own pipes not much larger than the stock header pipes (one pipe on each side of the motor) and it swept the driveway clean when the engine revved. Lots of pressure there. They killed power too. Torque was good but big blocked assembly's aren't cheap either. GLOWING plugs. Sounds like might whant to check for a potato in there. Did someone do somthing on purpose? I'd make sure jetting was far from the lean side, figure that to be the least one could do to run from an all entrapping BIG BLOCK ROAST.

Post edited by: nads.com, at: 2007/09/28 19:47

HP is what creates the heat, not engine size, keep the horsepower level down near 100 and it won't ever overheat.

But who's going to spend the bucks for a big inch motor, then limit the hp? No one I've ever met :lol: :lol:

The heat issue is not as big of an issue as some make it out to be. I would say that half of the big blocks we do these days are for streetbikes. Just finished a 1395 that will be shipping Monday.

As for the fins, the very first blocks had almost no fins as they were drag race only. The latest version is a permanent mold and has almost as much finning stock.

AS for glowing spark plugs... You have to jet these things.

oh everyones making a crack at my crappy jetting abilitys:lol:

i'm getting solomrus to do the motor work, jetting and such things... i have heard good things.

Set of Pipes


planning on cutting that at an angle and dumping it straight out under the belly.

basically - i don't mind avoiding rush hour, but i don't want to burn it up at a stoplight... with some serious jetting, a really free exaust, and an oil cooler... am I safe at stoplights? I don't mean commuting 40mins downtown, but am I safe to drive this monster around at 40mph and stop at stoplights for a while?

Post edited by: requiem, at: 2007/09/30 19:20

Post edited by: KZCSI, at: 2007/10/05 00:48

Check a stock cylinder......you'll see holes between 1-2, 2-3, 3-4 cyl. on a big block there are no air passages between the cylinders. If you want the motor to last, resleave if you want bigger than a 1105cc.

I've been following this thread as I have thought about taking my 750/4 up to 810. and I ave a question. can I keep my stock block and just replace the sleeves or will it require a rebore of the block and new sleeves as well?

Leather wrote:

I've been following this thread as I have thought about taking my 750/4 up to 810. and I ave a question. can I keep my stock block and just replace the sleeves or will it require a rebore of the block and new sleeves as well?

You would need to have your block (sleeves actually) bored out 3mm oversized to fit the 810 kit.