KZ650 Cam chain question

KZ650's used a non-hyvo chain for the cams. (sorry. I don't know what they are called). When doing the 810 conversion, it's been said that the stock cam sprockets must be used if changing the cams out. Are 650 chains superior to the hyvo's in the 750's? If not, can the 650 be converted to use the hyvo chains?:S

Thanks!

Bruce

There has been several disussions about putting a 750 head on the 650, and using the right chain, if memory serves, you have to change the sprockets out and followers to use the hyvo chain

Are 650 chains superior to the hyvo's in the 750's?

The roller-style cam chains used in the 650's up until, IIRC, 1980 or 1981 are NOWHERE near as durable (or as quiet) as the Hyvo chains used in the 750 and the later 650's. Kawasaki chose to use roller chain for the cams strictly as a cost saving measure because suitable Hyvo chains were certainly available. Note that the primary drive in the 650 was a Hyvo chain right from the start.
Brand H used Hyvo cam chains in their twin cam engines which were first offered beginning in the fall of 1978.....so the technology was certainly available. Kawasaki just chose to cheap-out when the engine was first designed and thus created a mild annoyance for most folks. Of course, hindsight is 20/20...

Even Honda, initially, used two roller chains as primary drive in the legendary-change-motorcycle-history CB750 of '69. Then in downsizing the engine for the 500,550,650 fours, switched to Hy-Vo chain in the 70's.

The Hy-Vo chain actually debuted in the Oldsmobile Toronado of '66, when they turned the transmission around 180 degrees, to make the car FWD. Hy-Vo was the primary drive in that car and its later twin, the Caddy Eldorado.

Kawasaki was one of the first ones to adopt Hy-Vo for the cams in '79. Even my excellent Yamaha XJ650 Maxim of '82 had still a roller chain on the cams. I simply think than most manufacturers did not realize the great durability and strengths of the Hy-vo until the mid '70s. The chain does make in-line engines a tad wider.

BSKZ650 wrote:

There has been several disussions about putting a 750 head on the 650, and using the right chain, if memory serves, you have to change the sprockets out and followers to use the hyvo chain

A roller cam chain crankshaft is just that only for Roller type chains ya can't make it a HyVo cam chain.

Lt.Dan wrote:

BSKZ650 wrote:

There has been several disussions about putting a 750 head on the 650, and using the right chain, if memory serves, you have to change the sprockets out and followers to use the hyvo chain

A roller cam chain crankshaft is just that only for Roller type chains ya can't make it a HyVo cam chain.

Yes the crankshaft on an older 650 is roller chain so that must be used. I'm not 100% convinced hyvo is any more reliable or long lasting anyway. So you have 10 or 20 whatever rows of chain in a hyvo, all are rotating at x RPM the entire time the engine is running. Using a roller chain the row is rotating at the same x RPM. Camshaft takes no real effort for the engine to turn, so maybe hyvo is stronger, doesn't matter as it's all wear from rotating. They are running in oil so either last a good long time. Jeff at Z1 said something like 30-40,000 miles on a roller camchain. I've gone 150,000 on the roller. I don't think a hyvo would be any longer lasting. Notice I "think", but could be wrong, most modern engines have gone back to roller chain cam drive. GL1800 Goldwing uses a roller chain and quite a few have 200K plus miles on them.

The Hy-Vo chain actually debuted in the Oldsmobile Toronado of '66,

Well, not actually, Hugo. It happened lonnnggggg before that. North American car/light truck engines have been equipped with Hyvo-type chains to drive camshafts since at least the mid 50's....and possibly earlier if anyone cared to look into this further.

GL1800 Goldwing uses a roller chain

Really ??? Didn't know that, Ron......but my ignorance of Wing-facts is legendary amongst my friends....and I'm happy in my ignorance. Thanks for throwing some light into a dark corner of my mind. I wonder why Honda chose a roller chain ??? Decisions like that USUALLY (but not always) come down to cost, in my experience. Interesting.....

H2RICK wrote:

The Hy-Vo chain actually debuted in the Oldsmobile Toronado of '66,

Well, not actually, Hugo. It happened lonnnggggg before that. North American car/light truck engines have been equipped with Hyvo-type chains to drive camshafts since at least the mid 50's....and possibly earlier if anyone cared to look into this further.

GL1800 Goldwing uses a roller chain

Really ??? Didn't know that, Ron......but my ignorance of Wing-facts is legendary amongst my friends....and I'm happy in my ignorance. Thanks for throwing some light into a dark corner of my mind. I wonder why Honda chose a roller chain ??? Decisions like that USUALLY (but not always) come down to cost, in my experience. Interesting.....

Your right H2RICK, the Hy-Vo has been forever on US engines driving camshafts. I meant debuted as 'primary drive' in '66, but even on that I maybe wrong.

On the Goldwings, it is true they use roller chain on the cams, but remember that initially they had belts. The Goldwings are automotive (My Mitsu and Frontier also have belts), and because of the flat engine configuration, and exposed front, replacing belts was a breeze, so should be with a roller chain. The point is, the cam chain in the Goldwing does not have to be as durable as in a in-line air cooled with the chain in the middle, when for a replacement you have to split the engine. Goldwings are also supposed to have a sedate, orderly life.

Use of a belt or Hy-Vo on a Goldwing six would have made the six-pots a little longer.

For what it is worth, to the best that I can tell, the 750 crank looks like it will fit the 650 crankcase. Someone correct me if I am wrong, but a lot of bearing and seal part numbers line up right if you take the crank from a 81-82 kz750, stick it in the kz650 case, bore the case to fit the jugs, and use a gpz750 head and cams. I am debating whether or not to use this method, or to just get a complete gpz engine and sell the kz650 engine.