Kawboy's restoration/conversion of a 1980 KZ13

Bucko wrote: Where does one get replacement seats?

KPMI, TRW, Federal Mogul, Serdi, Del West, SB International, Mahle, to name a few. SB International seems to be the go to up around here.

I have tig mig and arc welding seats to remove and bearings from shafts or in holes does work a treat
i normally put the item to fit (ie seats bearings ) in the freezer over night heat up by oven or gas (oxy acetylene) then drop frozen goods in, has always worked for me.
just have to work quickly.
thanks regarding the avatar info John
Dion

Looks like I'm headed to KPMI (Kibblewhite Precision Machining Inc.)for valve seat inserts. www.kpmi.us/catalog.html If you're looking for anything valve train, I invite you to have a browse through their catalog.

I will need to have the head machined slightly to fit 32 mm seats in the exhaust counter bores and 37 mm seats in the intake counter bores then install the seats and then machine the new seats to the factory measurement to give me 2.80 - 3.00 mm shims to start. We're going to get it right this time.

In the meantime when time permits, I got out the porting tools and started reworking the ports.

From this.


To this in about 20 minutes of work

Kawboy wrote: My plan was to warm the head up to 300 F and chill the seats with CO2 rather than nitrogen. Not sure where I would get my hands on a small quantity of N2.

Sort of off topic but dry ice and rubbing alcohol make a pretty good substitute for liquid nitrogen. I think it ends up around -80 to -100 degrees C. It worked for some bearing races on my dirt bike.

Hmmmmmmmmm a chemist in our midst. A little bit of this and a dash of that. Good to know. I'll check in to that. Hoping for .005-.006" interference fit. I'm well aware of heating to 300F. Maybe the next time I go to the skin doctor, I'll take the head with me and borrow his N² squirt gun and super cool the inserts . (But then he'll probably want to test ride the bike when it's done) :side:

Kawboy wrote: Hmmmmmmmmm a chemist in our midst. A little bit of this and a dash of that. Good to know. I'll check in to that. Hoping for .005-.006" interference fit. I'm well aware of heating to 300F. Maybe the next time I go to the skin doctor, I'll take the head with me and borrow his N² squirt gun and super cool the inserts . (But then he'll probably want to test ride the bike when it's done) :side:

I am indeed a chemist. Too bad you're not closer, I've got 2 160 liter tanks of the good stuff at the lab let us know how it goes though!