what is the valve seat angle of a KZ1100 head?

figures that they would use something built close to the fatherland. but it does look like a cool system

One of the great things was we could cut the head for a oversize valve seat with this set up, then once the seats were in the angles then cut. A lot of big valve ported and flowed heads came from that shop over the years.
I just did a Google for the Mira tools, and got several Distributors. Find a set up you're interested in and do a search. Bet there is someone close to the border if not in the Great White North!

There's one thing to consider that I didn't see mentioned.

Compression :huh:

J chambers are about 4 cc greater volume. You need J pistons and a spacer to do the job right or it's going to be anemic on acceleration.

Also will need an idler tower setup for the conversion.

If this is a relatively mild street motor, you may be further head keeping our Z head and have it overhauled..

JMO

Larry C

PS....if you do follow through with it, stand that top cut up a bit more than 30 degrees. A 35 is pretty good on them.

Have it done on a Serdi and have all the seats exactly the same.

4cc more in the J head. Thats the reason for changing heads. I'm struggling with the 1200cc and pinging engine. I already did some reseacrh on this forum. The compression is just to hig with the stock z900 head.
the set up is a reliable street engine with some added top. It runs quite easily 10-10.5k
Bit off topic but how to remove the black paint without sandblasting (cause thats ruining the "surface")
thank for all you good and fast replies!!

martijn wrote:

4cc more in the J head. Thats the reason for changing heads. I'm struggling with the 1200cc and pinging engine. I already did some reseacrh on this forum. The compression is just to hig with the stock z900 head.
the set up is a reliable street engine with some added top. It runs quite easily 10-10.5k
Bit off topic but how to remove the black paint without sandblasting (cause thats ruining the "surface")
thank for all you good and fast replies!!

You can try aircraft stripper. It half ass works but I still end up having to blast the KZ heads. You might call a professional paint stripping shop for a price.

Just be sure to ask about possible discoloration of the aluminum from stripping chemicals.

If it's got 10:25:1 pistons and still pings & you have already checked the ignition timing:

a]head might well have been shaved

b]midrange jetting could be too lean

c]cam timing could be too advanced on the intake

I can understand your approach but you should really inspect what you have before you conclude the J head is the solution.

Your KZ head is coming off anyway so clean the chambers and CC them.

Funny thing.....for decades everyone used stones and carbide cutters and went real fast. Now they're junk I don't think so.

Those blade cutters are real nice for getting things done quickly but I've seen guys screw up valve jobs pretty badly with Serdi & Goodson machines.

Call Gary at Wicked Motors and ask him what he thinks of his new Serdi ...

I don't want to Hi-Jack this thread, but:
Larry wrote;
"Funny thing.....for decades everyone used stones and carbide cutters and went real fast. Now they're junk I don't think so."
Well I can't see where anybody said that Stones were Junk, I must have missed that. Have you tried your stones on some of the late model hardened valve seats? I think dressing and dressing, that your stone will shortly be replaced. The carbide cutters, by whoever, are more to the "Current" market of technology. Stones have, and will continue to produce good seat surfaces, just a lot slower, and over time more expensive in both Labor and equipment.
this needs a new thread so all of the guys can discuss the benefits of each system/ brand.

i ported and polished an r6 head,and then had a friend of mine do a three angle valve job with his nice brand new kwik-way valve seat cutting machine.i had to purchase a solid carbide pilot(expensive)because the r6 stems were 4mm.
typically when i port a head i do a "rough in"valve job to see where the seats will be.being as how i did not have the valve machine at my house i couldn't do the rough in.so i had it completely ported and polished including the combustion chambers.when we cut the seats it dropped the 30 degree angle below the floor of the combustion chambers to get the 45 to clean up.which created steps around all of the valves in my nicely polished chambers.so then i had to go back and grind those steps out without touching the fresh seats and then polish back,tough job.
so being as how all three angles and lengths of each are cut into the insert i couldn't control that.
where as with my sioux seat grinding stones i can let the 30 degree(or possibly 35 degree next time,thanks for that tid bit mr. cavanaugh) angle run right out into the floor of the combustion chamber and dont have the step problem.
so with that one experiment i decided that a skilled operator with sioux seat grinding tools could do arguably as well as a seat machine.
i went to joe mondello's head porting technical school and he had a serdi which he taught us to use.i was already rebuilding heads at my job and porting two strokes.he asked us all if there was anything in particular that we wanted him to teach us.i said that i wanted to learn to do the best valve job possible with grinding stones.he taught me all his tricks,and said that it takes more time but we can do just as good of a job with stones as the serdi does with cutters.but he can teach an unskilled person to run the serdi quicker than he can teach them to properly cut seats with stones.

leon

sorry for the thread jack,
but stones have kept up with seats.they have stones that will cut any seat fast enough to ruin em if you are not careful.

leon

thats why i use carbides i can get into enough trouble on my own

larrycavan wrote:

If it's got 10:25:1 pistons and still pings & you have already checked the ignition timing:

a]head might well have been shaved

b]midrange jetting could be too lean

c]cam timing could be too advanced on the intake

I can understand your approach but you should really inspect what you have before you conclude the J head is the solution.

I tried all suggetions. The pinging drives me a bit mad after 2 years experimenting. A compression test after running in was 185-190 psi with a cold engine. Also tried some different lobe centers without result. Changed carbs, have been changing main and pilot jest resulting in an overrich mixture and doing a poor 26.
miles the gallon...

Did some vlave cutting now with teh original kawasaki 57001 tool kit. It worked very easy and verywell. The cutters made a clean and smooth surface. Now some lapping for a perfect seat..:woohoo:

u could try a cam with more duration. what cams are u running. what ignition are u running?
most guys that run stock heads and stock cams can overcome the ping . so u should not have any trouble with aftermarket cams.
i run a 1200 with 200 psi and no ping.35 to 45 MPG.
i had a ping on a previous build with 160 psi.a new Dyna 2000 ignition solved it.
not much point running a 1200 cc motor if u are going to give it all back with a low compresion head.
did u check the head for milling by cc-ing it?
what is your squish clearance?