Lots of Internal Pics + Good Tech Info

[rbabos]

At some point between prototype and final product, for some reason HD decided to change the rocker shaft restraint system to one that prevents it from rocking back & forth.

No, the prototype has a shaft restraint system but the final product has a simpler one.

Or Fred wasn't talking to Charley and it was found the original concept wouldn't fit under the rocker covers.
Ron

[Piston Broke]

rocked boxes here from the 80's that have set screws in them to lock the shafts.

What did they do ... grind a small flat or drill a dent in the rocker arm, and loctite in a set screw through the top of the butress that holds them?

Not a lot of metal there.

[rbabos]

rocked boxes here from the 80's that have set screws in them to lock the shafts.

What did they do ... grind a small flat or drill a dent in the rocker arm, and loctite in a set screw through the top of the butress that holds them?

Not a lot of metal there.

It's also ass backwards to the shaft load. You'd want to lock from the bottom and force the shaft upward so all of the load bearing surface is used and no extra pressure on the screw in operation. Not the smaller screw contact area, as would be the case if the screw was on the top.
Ron

[Durwood]

Lot's of good pics and info

   

[Piston Broke]

It's also ass backwards to the shaft load. You'd want to lock from the bottom and force the shaft upward

Do you think it's worth doing that way instead of with these bushes?

I was thinking you would put a flat or dimple on the shaft and hold it that way, not by pressure to the cover.

I only have some XR1200 rocker covers at hand. I don't think you could do it on the rocker arm side due to the closeness of the locating bolt, it'd have to be on the valve side only.

[jbexeter]

if they wanted to lock the shaft all you need is splines and clamp, can't go wrong and so on, probably costs an extra $5 in machining for each spline and cap set so 4 shafts 2 ends each $40 extra per motor.

50 bucks here, 50 bucks there, before you know it youve added 500 bucks to the motor build costs, and it is exactly in these areas that most of modern engineering design goes, what's the cheapest way to do x, not what's the best way.

I've seen worse, my old sohc 750 honda they just line bored the heads and then white metalled that and stuck the camshaft in, when it went south you bought a whole new head as well as a cam....

[rbabos]

It's also ass backwards to the shaft load. You'd want to lock from the bottom and force the shaft upward

Do you think it's worth doing that way instead of with these bushes?

I was thinking you would put a flat or dimple on the shaft and hold it that way, not by pressure to the cover.

I only have some XR1200 rocker covers at hand. I don't think you could do it on the rocker arm side due to the closeness of the locating bolt, it'd have to be on the valve side only.

The goal is to offer resistance to rotation on the shaft within the bosses, which occurs when the engine gets hot and the aluminum hole expands more then the shaft. This extra clearance allows the shaft to rotate back an forth from the rockers driving it, slapping the notch of the shaft against the bolt shoulder in the case of the TC. Several ways to stop this but it seems using the RockerLockers seems effective and no extra bs involved.

Ron

[Admiral Akbar]

if they wanted to lock the shaft all you need is splines and clamp, can't go wrong and so on, probably costs an extra $5 in machining for each spline and cap set so 4 shafts 2 ends each $40 extra per motor.

50 bucks here, 50 bucks there, before you know it youve added 500 bucks to the motor build costs, and it is exactly in these areas that most of modern engineering design goes, what's the cheapest way to do x, not what's the best way.

I've seen worse, my old sohc 750 honda they just line bored the heads and then white metalled that and stuck the camshaft in, when it went south you bought a whole new head as well as a cam....

The SOHC CB750s used cam/rocker towers.  Other models used heads (eg CB500F, CB360) Honda used base metal. Nothing special.

[rbabos]

if they wanted to lock the shaft all you need is splines and clamp, can't go wrong and so on, probably costs an extra $5 in machining for each spline and cap set so 4 shafts 2 ends each $40 extra per motor.

50 bucks here, 50 bucks there, before you know it youve added 500 bucks to the motor build costs, and it is exactly in these areas that most of modern engineering design goes, what's the cheapest way to do x, not what's the best way.

I've seen worse, my old sohc 750 honda they just line bored the heads and then white metalled that and stuck the camshaft in, when it went south you bought a whole new head as well as a cam....

The SOHC CB750s used cam/rocker towers.  Other models used heads (eg CB500F, CB360) Honda used base metal. Nothing special.

Correct.
Ron

[Durwood]

if they wanted to lock the shaft all you need is splines and clamp, can't go wrong and so on, probably costs an extra $5 in machining for each spline and cap set so 4 shafts 2 ends each $40 extra per motor.

50 bucks here, 50 bucks there, before you know it youve added 500 bucks to the motor build costs, and it is exactly in these areas that most of modern engineering design goes, what's the cheapest way to do x, not what's the best way.

I've seen worse, my old sohc 750 honda they just line bored the heads and then white metalled that and stuck the camshaft in, when it went south you bought a whole new head as well as a cam....

The SOHC CB750s used cam/rocker towers.  Other models used heads (eg CB500F, CB360) Honda used base metal. Nothing special.

I was wondering how long it would take you to come out and comment on this new engine...

[jbexeter]

The SOHC CB750s used cam/rocker towers.

You know, my first reaction was "no it bloody didn't" and then I thought hang on boy, been very nearly 40 years since you owned one and rebuilt it, go back and check before you shoot your mouth off, and you are of course correct, it did have towers, well it did when I bought it, and until you did what I did, which was fit a 900cc "kit" with a remanufactured head which had the towers welded to the head, worked great until the pirhana permitted 13,000 rpm eventually ate it up.

Thanks to you both for correcting me.

[PoorUB]

I've seen worse, my old sohc 750 honda they just line bored the heads and then white metalled that and stuck the camshaft in, when it went south you bought a whole new head as well as a cam....

Pretty sure you 750 Honda was just machined aluminum with no other treatment. Just bore the aluminum out and slap in the cam.

Typical construction of an over head cam engine, pretty much all OHC motorcycle engine are that way and come to think of it, any OHC automobile engine is too, so there are hundreds of thousands, if not millions of engines on the road with similar design that run for 100,000 miles or more with no issues.

[fattmann101]

do the jugs still have an iron liner? cant tell from the cut a way  pic

[Xyzzy]

do the jugs still have an iron liner? cant tell from the cut a way  pic

"The new cylinders are constructed with cast iron linings."

[FSG]

Note my comment over a year ago ..   

"The SPROCKET SHAFT SPACER looks to be thicker and not tapered at the end(s) than that used in previous years"

The SPROCKET SHAFT SPACER looks to be thicker and not tapered at the end(s) than that used in previous years




and the inside of the rotor where the spacer contacts is not undercut like previous years

so with the stronger magnets and increased output one would hope that stripped rotor splines are confined to history




I'm interested in getting a closer look at the outside of the rotor