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pelican

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I'm trying to put my engine sprocket back on, but the key is not going back in the shaft. Are they usually a super tight fit? Tried freezing it to see if it would shrink, but it didn't work. Was thinking about filing a small chamfer on the edge of the keyway- would this hurt anything? Any other ideas?

Also how close does the back of the engine sprocket get to the oil seal?
 
Could be the key has a high spot, try relieving it by rubbing on some wet and dry until it fits, filing is a bit extreme.
Not sure on Q2 never looked!
 
The edge of the key or the cut in the shaft can get a small nick when it is removed pretty easily when they have sharp edges. I take the edge of my utility knife and scrape along both to see if I find a spot that it hangs up. Sometimes the knife edge is enough to smooth it off well enough to make them slide together, otherwise I use a fine file or bit of fine sandpaper. I have folded 400 grit sandpaper over the end of a flat blad screw driver and used it to relieve the edge in the shaft a tiny bit. Obviously you don't want to make it loose in there.

So far I haven't blown up much stuff by doing this.

Russ
 
Agh, such little nothings that are such big show stoppers. Might magic marker the shaft and key to see what is rubbing if the above do bring nice fitting joy.
When correct fit and aligned should just slip on almost full seating by hand.
 
After feeling the improvement in trimming donut rims ~1/2 narrow on Peel I'm going try it on Trixie Combat to see if softens her vibes sooner. Trixie goes w/o any rod links to retain factory quirks in handling limits, but still a rather competent handler I want to feel like a sane flying carpet. Someone else take a chance on my report and let me know its just my fantasy or real improvement.
 
hobot said:
After feeling the improvement in trimming donut rims ~1/2 narrow on Peel I'm going try it on Trixie Combat to see if softens her vibes sooner. Trixie goes w/o any rod links to retain factory quirks in handling limits, but still a rather competent handler I want to feel like a sane flying carpet. Someone else take a chance on my report and let me know its just my fantasy or real improvement.
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Wrong thread again?
 
I'm gonna try to file it down a little.

I ask about the closeness to the oilseal because of this new circlip I put in.
primary question


Is this normal? 1. It's awfully close to the shaft 2. when I put the sprocket in it does go in the recess, but I can't tell if it touches the circlip or not. I don't want anything to get damaged. The old circlip I took out did not have this bent portion, and it was a lot tougher to get out.

Is it ok as is, or should I take it out and snip part of the bent section off to make more tolerance?
 
pelican said:
The old circlip I took out did not have this bent portion, and it was a lot tougher to get out.
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Well, I haven't seen a circlip with a bent section like that before?
 
Filing woodruff keys falls under the heading of 'fettling' as far as I'm concerned. It's far better to do that than to force it into the keyway.

That curved tang on the circlip is most odd. If the original is still available, I'd use that. It doesn't usually distort and this is not a safety-critical application. I can't imagine a properly seated clip ever coming out on its own.
 
cool, I guess I'll just snip it off. That's how it came new from oldbritts via AN.
 
"Adjust" the key as needed and as noted in other posts - I use 400 wet or dry for such purposes (and also for truing carb/manifold surfaces). Remember that the purpose of a keyway on a tapered fitting is NOT to hold the item in place; the properly torqued nut or bolt and the taper itself does that. The keyway is for alignment/ease of assembly. If you could mount the rotor in the correct alignment for timing purposes, you would not need the key at all.
 
Good going getting another puzzle piece placed Pelican, Looks so good nice and clean too. I've no ID how my isolastic post showed up here, but glad there's happy ending to your dilema. I expected to have an engine to start in 2 wks but may be 2 months. Did find all the barrel and head fasteners.
 
right on. engine is too complicated for me, I'd be too scared to mess something up.

had to stop 4 tonight
my clutch basket definitely has some wobble- I searched some threads where it says it's normal though?
my sparx rotor is undersize! - seems this is normal too from other threads
 
MexicoMike said:
" Remember that the purpose of a keyway on a tapered fitting is NOT to hold the item in place; the properly torqued nut or bolt and the taper itself does that. The keyway is for alignment/ease of assembly. If you could mount the rotor in the correct alignment for timing purposes, you would not need the key at all.
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Throw your key away next time and see how long it is before you are walking home, the timing rotor is located seperatly isn't it?
I know what you are saying about a good taper holding , but it still require the key to stop it moving, or a much bigger taper and alot more torque.
 
pelican said:
right on. engine is too complicated for me, I'd be too scared to mess something up.

my sparx rotor is undersize! - seems this is normal too from other threads
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It fits on the shaft but the nut won't fit inside it? Better to have to fit it so it's tight than have it sloppy.
 
Yoose guys must not have handled a real tapper shaft torque connection,
I 2nd - 100% with Mexico's statement, the key way is mere locating device and temporary holder until the nut forces metal faces to fuse- with Vanderwall's forces and Hydrogen Bonding. If two highly polished flat plates are brought together they can be a booger to separate w/o any clamp force applied.
Just consider the force required to start the sprocket off the tapper, it ain't the key way resisting that, just the surface mating refusing to let go easy.

If tapper torque connection is made well a key is pure optional addition, unneeded if pulley-sprocket position is not important on initial install.
A straight shaft cut is same principle but not a binding as tapper. There is also the principle of similar alloys resting against each other, like carb slides compared to brooze or Al slide in pot metal bore.

Taper Shaft or Bushing

A common method of introducing an interference is to manufacture a tapered shaft and tapered bore. At installation, axial force is applied (by tightening a nut against a thread on the taper shaft's end) to advance the hub along the tapered shaft (Figure 4).
In this case, the axial force is
Equation 18 (18)
Take care that the design accounts for the parts' change in axial position. Furthermore, you'll need a method for removing the part later. You can also use a key and keyway, parallel to either the taper or the shaft centerline, for insurance in case the axial load isn't maintained.
Click to expand...
http://www.isa.org/Content/ContentGroup ... ctions.htm
 
swooshdave said:
pelican said:
right on. engine is too complicated for me, I'd be too scared to mess something up.

my sparx rotor is undersize! - seems this is normal too from other threads
Click to expand...

It fits on the shaft but the nut won't fit inside it? Better to have to fit it so it's tight than have it sloppy.
Click to expand...


no, not even. the rotor is .7495 and my shaft is .7505...at least the rotor nut is good at .749

tried stator today... everything is way out on that too. The round metal is too wide to fit in the outrigger plate. the recess's in the epoxy are too narrow to fit the studs.
 
So HOBOT, you will be throwing the key away then will you ,as it serves no purpose, might pay to keep it in your back pocket.
 
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