Ask an Engineer

[ducatilover]

No doubt there will be a few youtoooobe vids out there.
I would expect them to be cast iron though?

[carburator]

Mr ocean, ( clever bugger ) has discribed pretty close how to do it,
however Id do it his way with a couple of changes. and I have done this
for a cam train. external ajdustable sleves...

machine the cam for a sleve, make up a ajustable coupler ( think adjustable timing gear set )
or even machine coupler, scotch key it to the camshaft ( with a 0.015 shrink fit ) have a o ring grove
to contain the oil ( oil issue sloved ) but also it builds in adjustment to align both cams exact

Id do drawings on a napkin and photoshop it if you like but im on crayons at the moment..
and i can;t find the photo's of the one i did for a engine at the moment either..

but i used 4mm allen keys *6 and never had issues of movement plus I could dial the cam spot on..
no oil loss issue nor issues of alignment for journals..

[Ocean1]

No doubt there will be a few youtoooobe vids out there.
I would expect them to be cast iron though?

Chilled cast iron usually, and now you've got me thinking whether they use speroidal graphite or not...

Don't matter for the purpose of this excercise, and the sparks will look very similar. Actually if you can see rough cast surface there's almost no way it's steel, it'll be some sort of CI.

[Ocean1]

( with a 0.015 shrink fit )

Yes, perhaps a thou is a tad ambitious. Don't want too much heat on the sleeve, either.

[ducatilover]

Thanks Carb. The clearance issues I'm worried about are the sleeve hitting the oil feed rails that run over the cam as seen here I think I may just get away with it though... right, got to google the fancy engineering phrases (I'm only a mechanic!)

Could you elaborate on the adjustable coupler please? In my fuzzy brain I'm seeing to splined cups pressed on to each side of the cut in the cam...


Ocean, they're a cast surface, but I'll double-triple check at home.

[ducatilover]

There's also the cam locating ring on the exh side between 3 & 4, you'll see in the first pics.
I suppose this could be made to be incorporated in a sleeve?


Edit, after some googling, I think I'll go with a pressed in part, with a round keyway or two/scotch key. I'm confident it'll be up to the task!

[carburator]

Yes, perhaps a thou is a tad ambitious. Don't want too much heat on the sleeve, either.

Umm..

0.1 ( hundred thou )
0.01 ( ten thou )
0.001 ( one thou )

Oh bugger are you driving metric or imp ?

[carburator]

There's also the cam locating ring on the exh side between 3 & 4, you'll see in the first pics.
I suppose this could be made to be incorporated in a sleeve?


Edit, after some googling, I think I'll go with a pressed in part, with a round keyway or two/scotch key. I'm confident it'll be up to the task!

The cam locating thing you are refering to in the pictures ( thin disc ) is the splash oil system to get
oil to the inside of the camshaft. ( it does stop it moving around as well..)

Id be honest you get a bunch of engineers together and there always is different points of view..
Will draw ( find photos ) later on today..

[Ocean1]

Oh bugger are you driving metric or imp ?

Either. I design and build metric but I often convert to get a sort of "second opinion" for tolerances.

I'd originally suggested 0.025mm (1 thou), but 0.0125 (1/2 thou) is less likely to cause issues assembling it, and if the sleeve is reasonably long it'd be safe for whatever bending moments the shaft will get.

[ducatilover]

Either. I design and build metric but I often convert to get a sort of "second opinion" for tolerances.

I'd originally suggested 0.025mm (1 thou), but 0.0125 (1/2 thou) is less likely to cause issues assembling it, and if the sleeve is reasonably long it'd be safe for whatever bending moments the shaft will get.

The space I will have to use won't be very long, I'll measure it all up, but I expect I'll have somewhere between 50-60mm at the most for a sleeve

Just hunting eGay for a set of ZX6E cams now and we'll be in business
I'll have to figure out if the more aggressive profile will be beneficial, the E model has a more aggressive ramp on them compared to my D model but similar duration, so that'll increase the stress everywhere, and make it peakier.

I've answered my own question there, I'll use original cams...

[Ocean1]

The space I will have to use won't be very long, I'll measure it all up, but I expect I'll have somewhere between 50-60mm at the most for a sleeve

Should be OK, insertion depth the same as the diameter would mean bending forces are not agrivated through the sleeve.

Re scotch keys, how are you going to drill, (and ream?) the axial hole?

[bogan]

Re scotch keys, how are you going to drill, (and ream?) the axial hole?

And more importantly, are they even of any use in this application?

[ducatilover]

And more importantly, are they even of any use in this application?

Should be OK, insertion depth the same as the diameter would mean bending forces are not agrivated through the sleeve.

Re scotch keys, how are you going to drill, (and ream?) the axial hole?

No idea to both, that's why I've posted in here for you clever buggers
I was assuming it'd help reduce the risk of the cam twisting in the join (remember, I know nussing about engineering stuff)

If it's not needed, I won't do it

[pete376403]

Honda used, on the 6 cylinder CBX1000, Oldham couplers to join the two halves of the camshafts together. Would these suit your purpose?

[ducatilover]

That's quite the idea

If the chaps here say it'll work, I will make that an option.
The cam lobe will be turned 180 deg, so it it doesn't run/sound pretty enough, I could in theory just turn it back around...