TOPIC:

Okay, so it's been a LONG time since I had a few moments to work on the project. Since retiring I've been busier than a one armed paper hanger.

Anyway, a brief catch up here. My goal has always been to spoof my KZ to look like a CBX complete with a Candy Glory Red paint job. One of the "mods" is the tail section. I've built the CBX wing on the back with balsa wood and epoxy fiberglas. It's almost complete short of a little fairing work with the epoxy and micro ballons. That portion is coming along nicely.
In one of the previous posts "Trikebldr" commented on my glass work and suggested that I glass in the storage compartment and ditch the tiny plastic tool box. So it's his fault that I did it. I built the floor of the compartment out of 3/16" balsa wood sheeting and epoxy glassed both top and bottom then fitted it into the tail section and epoxied it in. Than I glassed in the rear of the tail section and that created a sealed in tail section. The tail section is so rigid that I was able to eliminate the 2- 6mm bolts in the back of the section which bolt to the rear light bracket. Now there is 4 bolts holding the tail section to the subframe.

Some might ask "1/4" balsa wood, must be flimsy? " Nope, it's not. I can push down on that wing on the rear of the tailsection and lift the front wheel off the ground when the bike is on the centerstand.

Any way, here's a pic of the new cavernous storage in the tail.

I've procrastinated long enough on the engine work. I decided to look at the work I had done on the cylinder heads. I asked for the valves to be ground and the valve seats cut, so now it's time to measure things up and assemble,,, or not............

First checked the valves and found after installing each of the valves in the same seat and measuring, all of the valve are within .003" installed length. Not bad, but the installed height measured with a vernier is 1.505" which is 38.07mm . Now I could gring the ends of the valve stems .3 mm and get the head back together but down the road there will not be any shim sizes available to adjust with.

So, not happy. I had a set of camshafts ground almost a year ago and the idiot that ground them was told that I could afford to give up .025" off of the base circle but he took .150" off of the base circle and turned the cams to scrap.

1 option that I could do here is have another set of camshafts ground at another shop and ideally the installed height needs to be 37mm and I'm at 38mm, so if I had the cams reground and take 1mm off of the base circle and clean up the profile, I'll be back in the money again. The trick is to find a REPUTABLE shop that can and will do as I ask. I might try asking Comp Cams and see what they say.

Kawboy wrote: Now I could grind the ends of the valve stems .3 mm and get the head back together but down the road there will not be any shim sizes available to adjust with.

Not sure I get this - the clearances will close up over time so the shim sizes should go down(??).

hillsy wrote:

Kawboy wrote: Now I could grind the ends of the valve stems .3 mm and get the head back together but down the road there will not be any shim sizes available to adjust with.

Not sure I get this - the clearances will close up over time so the shim sizes should go down(??).

The problem is right now the valves are sitting too deep in the heads so by grinding the stem by .012" I could assemble the head but the shims would be the thinnest shims available. As the valve wear, the valves start going deeper into the head and you end up reshimming with thinner shims. If you are already at the thinnest shim to start with, there's no shims smaller to reshim with.
There's such a small margin to work with on a bucket shim valve set up.In the case of the KZ1300, you have to get the valve stem to the spring base within 37.90 - 38.00 mm in height. That's .044" . If it was a rocker arm set up like the hondas, you could miss by a mile and still get it set up to run.

I had an interesting conversation with Delta Cams regarding welding and regrinding my camshafts. After understanding what I had to work with, they proceeded to inform me that they had previous experience trying to do this type of work on the KZ cams and it was all bad. They determined that the cams were made from sintered metal casting and that no welding process would work on them. They said that as far as they are concerned any damage on the cams would render the cams scrap.

Now I did have a set of cams reground to .350" lift and 280 duration but when the shop did this, the base circle of the exhaust cam lobes was almost gone and the intake lobe base circle was almost gone, so those cams are probably scrap. I could install valve lash caps on the end of the valves and probably get things back in spec, but that would be a bastardized set up.

I do have a plan forward. Currently a set of stock cams would fit and I could shim with 2.05mm shims but then when I go to adjust the valves down the road, there won't be any shims left available to shim with (possibly 2.00mm but that's all) I need to find about .028"-.032" of clearance to get back to using shims in the 2.50mm-3.00mm range. That means that if I go back to the guy who ground the first set of cams and restrict him to selecting a new profile that will remove .028"- .032" from the base circle and also aim for a 280 degree duration, I'll be back in business.

I also had an eureka moment while studying the cam shafts. the intake cam and exhaust cam were made from the same casting and then machined. the intake cam did not get the screw thread cut in it for the tachometer gear, but the metal boss is there in the casting. The intake was ground to 270 duration and .320" lift where the exhaust was ground to .300" lift and 280 duration. One could vertually exchange the intake and exhaust cams PROVIVED the timing markings on the gears was repunched.

So if I started with 2 intake camshafts and had the base circles ground down .032" and duration opened up to 280 duration and also had the tach gear thread machined onto one of the cams, I could end up with cams with .350" lift and 280 duration. That's not quite where I wanted to be at 375" lift but if the cams don't get welded and just reground, the savings is about $900.00 U.S. since Megacycle cams wants $1300.00 U.S. to do this work which Delta says can't /should not be done.

I still have a plan for adjustable timing gears. I just need access to a lathe. Oh Lord, please, a lathe for Christmas.





You can see the cam lobe height difference. There's a lot more material in the intake lobe to work with.
And I just bought 2 more sets of camshafts off of EBay to experiment with. (Don't tell the wife)

Kawboy's going to be deadly now. Just bought a baby lathe, big enough to fit the camshafts in. I'll modify a tool post grinder to fit the lathe and grind my own camshafts. THEN we'll also get around to doing the camshaft drive chain gear modification to allow adjustment of the camshafts. Now I'm getting back into my old life style. Looking forward to some serious intellegent modifications. Yipee !!