Somebody Blew It

...a long time ago, I'm guessing.
 



Acquired an 84 ZN1100 motor and I have a few questions.
This seems like a good place to start.



Not sure I like this Kawasaki 11004-1104 gasket, though I've had good luck with the fiber type.

What could have caused such a failure?





The head is flat

Ok then, here's another question...

What purpose do the vertical factory-cut openings between cylinders and the cam chain tunnel serve, as shown in the cylinder block image below?

Looks like it wasn't torqued properly then retorqued too much.  
The vents help cooling the barrels. 
The big bore kits don't have them so overheating becomes a problem on a street bike. 
Steve

Thanks Steve.

That pic is of a cylinder block I have saved for some as-yet unknown purpose.

My new/old, potentially useless ZN1100 cylinder block has several un-cut vents, which likely contributed to the head gasket's demise directly above.





I'd like to salvage this block, but it may only be good to have bored for oversize pistons.  It looks to have sat for some time...

You can drill out the blocked vents then file them smooth. When I had the Z2 750 block bored to 1015 you could still see rust stains from when the block sat out in the weather. That tells you how porous the steel is but I ran it anyway. When I opened it up the sleeves were polished smooth so I installed new Wiseco pistons and RODE THE PISS OUT OF IT in 2014. Had an oiling problem in 15 so I got a low mile 1015 block and ran it. 
I'd keep the block and maybe take it out to the limit or just keep as a spare. I like spares. 
Steve

SWest wrote:

You can drill out the blocked vents then file them smooth. When I had the Z2 750 block bored to 1015 you could still see rust stains from when the block sat out in the weather. That tells you how porous the steel is but I ran it anyway. When I opened it up the sleeves were polished smooth so I installed new Wiseco pistons and RODE THE PISS OUT OF IT in 2014. Had an oiling problem in 15 so I got a low mile 1015 block and ran it. 
I'd keep the block and maybe take it out to the limit or just keep as a spare. I like spares. 

Steve
 

If those unopened vent spots were responsible for the great blow-out in this old-beautiful ungine, seems the manufacturer may have been technically irresponsible to some form of degree, IMO.  
                                          

Great suggestion to drill them buggers out. 

I have so many spares, my trunk is full.  I hate to sell my house for having to move them.  I know the general location of every one, if you know what I mean.

Hi i am not sure why the head gasket blew ,but guessing to high compression and overheating on 2 and 3.About the cylinder holes that is clogged or not bored.On my 900 i had to use a metal pick and dig out a lot of gravel and dirt that was burned to a rock hard mass clogging the cooling holes.
i post a pick of that. Now for the sleeves that looks to be same problem that i had .Engine may have standing  unused for a long time with
water in cylinder.When i bought new sleeves for my kz900 about 1 moth ago they turned out to bee way to big as zed1015 told me.Anyway i think they might fit your 1100.
I can sell them to you for 20 usd each plus shipping form Norway if you want them.In the pic i hold a 1200cc piston and it is a little too big for the sleeve. You can see the measurements on the sleeves and compare if they are the same as yours.or maybe zed1015 know if they fit.I can take more measurements of them if you want.

Rolf1976_KZ900 wrote:

Hi i am not sure why the head gasket blew ,but guessing to high compression and overheating on 2 and 3.About the cylinder holes that is clogged or not bored.On my 900 i had to use a metal pick and dig out a lot of gravel and dirt that was burned to a rock hard mass clogging the cooling holes.
i post a pick of that. Now for the sleeves that looks to be same problem that i had .Engine may have standing  unused for a long time with
water in cylinder.When i bought new sleeves for my kz900 about 1 moth ago they turned out to bee way to big as zed1015 told me.Anyway i think they might fit your 1100.
I can sell them to you for 20 usd each plus shipping form Norway if you want them.In the pic i hold a 1200cc piston and it is a little too big for the sleeve. You can see the measurements on the sleeves and compare if they are the same as yours.or maybe zed1015 know if they fit.I can take more measurements of them if you want.

 

Might not have been the case here, but a tach drive leaking oil can mimic a leak in the cam chain tunnel O-ring area due to the way the oil blows back into that space while riding.

Goor Ridin'
slmjim & Z1BEBE

I doubt that those cooling passages being blocked is responsible for the failure of that gasket.  I'd punch them out when reboring, though.

slmjim+Z1BEBE wrote:

 

Might not have been the case here, but a tach drive leaking oil can mimic a leak in the cam chain tunnel O-ring area due to the way the oil blows back into that space while riding.

Goor Ridin'
slmjim & Z1BEBE

I know and i checked the tach drive for leaks PO had had the bike into a kawa dealer that had replaced the orings.After washing engine i stuffed paper into the area around the tacho drive .It was leaking a tiny bit but still came oil from the area on the picture

 

Daevo sorry for highjack the tread .if you want the sleeves you can have them for 40 usd for all 4 shipping from Norway is about  40usd i think i will check if you vant them

Rolf1976_KZ900 wrote:

Daevo sorry for highjack the tread .if you want the sleeves you can have them for 40 usd for all 4 shipping from Norway is about  40usd i think i will check if you vant them

If Daveo doesn’t want the sleeves I’d be interested. TY.