Headwork Source

My first post so be gentle. I'm looking for a shop to set up my '74 Z1-A head with new valves. My mission is to go totally stock and this is a street motor. I don't want to sink the valves into the head so far that I lose compression. I have one shot to do this right and I'm asking for the "best" shop known to man.
I've heard that some people don't even do the seats, they just install new valves and lightly hand lap them. Any input? Thanks and ride safe, Steve

a stock valve job isnt that complicated.where are you located?:whistle:

My motor only had 29,000 miles on it but since I was putting in a Wisco 1075 kit I thought I would do it right and get the heads redone also. I called around and found a place in Dayton, Ohio that seemed like they knew what they were doing. I had them do the seats and the valves and clean up the ports. They also took a light cut off the surface off the head to make sure it was straight. When I got it back I never checked the valve stem height (BIG MISTAKE) but just anxiously put it all back together with my new Wisco pistons. Well, when I went to adjust my valve clearance I found I didn't have any even with the smallest shim . After much screwing around I managed to save the head by buying new valves and grinding stems and valve keepers. I guess what I'm trying to say is make sure the shop knows what they are doing. It probably wouldn't hurt to discuss it with them and copy the pages out of the manual that shows the valve stem height measurements. You're right in that you only have one shot at getting a good valve job or a piece of scrap. Also, when you talk to the shop ask if they have a Serdi valve grinder as that machine makes all 3 cuts at once and is supposed to be the best for this head. Just my 2 cents, good luck.

Schnitz racing is a good place to have KZ head work done. The guy in there machine shop has been doing KZ heads for a long time. I have had two heads done there and they all turned out very well and there prices are resonable also.

There is no reason to sink the valves so much that the keepers have to be ground unless the head has had many valve jobs.

Did they change out the guides? No Z1 with 29,000 on the motor has guides that are still good.

Any reputable shop will send the head back with the valve stem lengths in the shim range.
kzzone.com/cams.html scroll to the bottom

Jay

I'm located in Lake Elsinore, CA. I also sent a head to a "famous" shop in Florida to have the valves freshened up. I'm a machinist by trade and I checked the valve guide I.D.'s and they were is spec. When the head came back the workmanship was beautiful, with the 3 angle seats. The problem was the installed height. I had to grind the retainers to clear the tappets and the compression after breakin was only 105 PSI. A brand new KZ650 motor that ran like a worn out one! I'm not gonna let that happen again with my Z1. I'm a good machinist but I don't do valve work and don't know the everyday tricks that are learned by these specialists. I also had problems getting straight correctly sized bores done on the KZ650. I sent it to another famous shop in LA and they came back bellmouthed on both ends and way too tight. The motor would have eaten itself except that I checked them with a dial bore gage. I had a local PWC shop straighten them out. I trust these guys but they don't do 4 stroke valve work. I've been to Schnitz Racing on line and they might be where I send my precious cylinder head. Thanks for the replies, Steve

id give A.P.E a call and see what they can .ive never had them do any machine work but i have bought and used a lot of their parts in my motors with no problems.

If you are a machinst and decided to grind the retainers instead of the valve stems (as is common practice) to achieve the correct stem length, I would be very surprised. Why grind the retainers?

George;
On shim on bottom Kawasakis, if the valve has been sunk way down in the head, you have to grind the valve tips to get the stem length correct for it to shim. When you do this, the retainer now sits very high on the valve. If you put a thin shim in, it will sit way below the top of the retainer. When you assemble it and try to shim it, the bucket will be sitting on top of the retainer and not making contact with the shim.

In this situation, it is necessary to machine the top of the retainers so they will clear the buckets and allow it to make contact with the shim.

Jay

Since you don't seem to mind shipping to Florida, I've used a fellow by the name of Joe Hooper for machine work before. He's in Orlando area and his rates are really competitive and so far I've been happy with his work. You can reach him at joehooper@cfl.rr.com

Tell him Henry from Philadelphia sent ya.

Thanks Jay, I was unaware of that as I have never owned a shim under bucket Kaw... most of my bikes are standard fare 900s/1000s... I did own a 550 GPz a number of years ago but never did a valve job nor have I done much valve work other than set clearances on the smaller displacement vintage Kaws.

I suspect if I didn't have a local shop, APE sounds like they know what they are doing. They are one of the few shops out there that stays loyal to doing vintage bike work and deserves support as a result. I use a local shop due to expediency as most all the machine work done for me is for a customer's bike but once the local place closes, as it will when the owner retires, I will start to have to send work off and APE would be one of my choices. When you get down to machine work, I don't like to nickel and dime and go with the low bidder. The reason I don't have some automotive machine shop do the work, although they would be FAR cheaper than the bike machine shop I currently use, is that they screw EVERYTHING up on a bike... All of them. They don't understand bikes. I have SEEN what automotive bike shops do with bike valve seats... I bet their ain't enough retainer material to get them down on those buckets after Joe's Chevy Big Block Machine Shop is done with them! bwhahahaha Those seats are about 2 inches up in the head...

wiredgeorge wrote:

Thanks Jay, I was unaware of that as I have never owned a shim under bucket Kaw... most of my bikes are standard fare 900s/1000s... I did own a 550 GPz a number of years ago but never did a valve job nor have I done much valve work other than set clearances on the smaller displacement vintage Kaws.

I suspect if I didn't have a local shop, APE sounds like they know what they are doing. They are one of the few shops out there that stays loyal to doing vintage bike work and deserves support as a result. I use a local shop due to expediency as most all the machine work done for me is for a customer's bike but once the local place closes, as it will when the owner retires, I will start to have to send work off and APE would be one of my choices. When you get down to machine work, I don't like to nickel and dime and go with the low bidder. The reason I don't have some automotive machine shop do the work, although they would be FAR cheaper than the bike machine shop I currently use, is that they screw EVERYTHING up on a bike... All of them. They don't understand bikes. I have SEEN what automotive bike shops do with bike valve seats... I bet their ain't enough retainer material to get them down on those buckets after Joe's Chevy Big Block Machine Shop is done with them! bwhahahaha Those seats are about 2 inches up in the head...

hey,wait a second i just dropped off an extra head at joes machine this morning:S i didnt see any bigblock chevys,but i saw a couple real nice kawasakis though ill post some pictures.hes also got a complete 82 csr 1000 with 10,000 miles on the motor if someone needs a cheap j-motor.