Kawboy's restoration/conversion of a 1980 KZ13

I just want to throw this bit about porting into the mix.

>>>>> www.carpenterracing.com/headporting.htm

It's not just about polishing up the passages, but a design exploring how the gases behave in changed geometry and the impact on the power output. Which I am sure we know. These are very volatile environments in very confined spaces.

StanG wrote: I just want to throw this bit about porting into the mix.

>>>>> www.carpenterracing.com/headporting.htm

It's not just about polishing up the passages, but a design exploring how the gases behave in changed geometry and the impact on the power output. Which I am sure we know. These are very volatile environments in very confined spaces.

Oh trust me, what I do is not "porting". I have die grinders in various sizes and carbide burrs, sanding drums and sanding cones. My only goal is to clean up the flashing in the castings and remove any obvious "flaws" so that the ports have a smooth transition from one end to the other. Removing too much material will screw up the velocity of the gases in the ports and have an adverse effect on low speed operation so my goal is not for better flow at high RPM, just better more balanced flow.
I'm also preparing the exhaust ports for a coating of. Eastwood's internal exhaust coating It's an experiment to see how well this product holds up in the cylinder head. I'm also going to apply this inside a new set of DG headers and see how well this keeps the heat in the exhaust until it exits out the end of the exhaust. Trying to keep the heat down at the front of the engine and help keep everything cooler. Just me messing around. It's what I do. Lots of testing and monitoring. Call it my fascination.

I see. I didn't mean to imply you don't know about these things of course. I know many people think it's just about polishing the hell out of those passages, and go at it real good - not so good for the engine! haha Looking at my head (too late for the one already on the bike), I've been thinking about doing the same - just a clean up. But more than intake and exhaust, the casting is quite 'dirty' where the engine coolant flows. Quite bad especially behind the pump impeller. I think this would be worth of some attention.

That Eastwood coating sounds interesting and has a few 'five starts'. Too bad I didn't know about it when putting the bike together - I sand blasted the pipes and mufflers inside, so they were very well prepared. Now I'd only remove them if the head has to come off, and that shouldn't be necessary anytime soon. I don't remember exactly when scotch bought his bike, but I think he never removed his head so it has to be something like 30 years? And his bike runs good. That's a looong time from now, quite possibly none of us will around to do it or read reports.

I totally relate to your 'tinkering spirit'. I have so many ideas popping up in my head regarding this bike. And in general. Kind of a 'never sleeping mind' syndrome, haha
I definitely need a lathe with a mill attachment, drill and a welding machine to implement anything seriously neat though. A benchtop lathe like you have, that's just fantastic. You can make so many useful tools with it!

Yes, you can see how my quest to restore that KZ turned into a KZ passion! haha You've witnessed it. I have to keep myself in check though as I have many other things I want to do and they conflict with running a bike shop at my place.

I see you are slowly getting things sorted out on your project. Once the cylinder head will come back things will move forward.
I don't think I've seen photos of your engine or other details of where the bike is at now. I'm really curious to see
Cheers!
Stan

Bit the bullet this morning and ordered new valve inserts from Kibblewhite Precision Machine Inc. KPMI catalog page 282
10-SC330 which is a 33mm insert in powder metal for the exhaust and 10-SC370 which is 37mm for the intake seats. In discussion with a Kibblewhite engineer, I discussed the possibility of using their aluminum bronze seats and they suggested that you could, but as far as he was concerned, the new powder metal seats they sell is a vast improvement from the original seats and probably far superior to the powder metal seats of even 5 years ago.
The diameters of both the 33mm and the 37mm are too big for the counterbores in the head and I could have the head opened up to accept the new seats but there's very little metal in the web between the 2 counterbores. So the plan will be to machine down the OD of the inserts to fit the existing counterbores and leave .006" for interference fit.

The parts are coming in and starting to pile up. Maybe when I get back from Panama, mother nature will warm up the earth enough so I can heat the shop without calling Alberta to turn up the gas flow.
These little beauties came in today.
B42/55 air jets in size 280 (which is 2.8mm or .110")

We've got LOTs of gas down here in Texas. I just looked for you and tomorrow's price is $2.79 per 1,000,000 BTU.