Rupp Turbine cotter pins???

[Tom Smith]

Drill a hole the loop of the cotter pin will fit thru between two fins directly above the cotter pin hole in the spindle. The correct length cotter pin will drop straight thru the drilled access hole without any issues. Then be sure and assemble the wheel with the valve stem over the hole so you can't use it.

[Kurt Bogerman]

Tom, I was tempted to drill a hole, but I was also hesitant to permanently alter the wheel.  I like the idea of hiding it with the valve stem.  The safety wire in your picture is similar to one of my attempts the other night.  

I think I'll probably settle on nylock castle nuts and a dose of safety wire.  The fewer holes to drill the better, all else being equal.

Tom's photo begs another question:  Are the acorn nuts on my outer rims OK for track use?  I have acorns installed and nylocks at the ready for the rims, but should FLEXLOC-style nuts like those pictured be used?  My studs are still 10-32, BTW.

Also, I'm pretty excited because my Grand Prix frame is waiting to be picked up tomorrow after being painted today.  I think I'll have a time tonight to post a picture or two in the Member Collections thread.

-Kurt

[Scott Elkes]

I remember my 1963 Dart Kart Grand Prix turbine wheel (4” front) using Castle nuts and curving the cotter pin. I seem to recall before inserting them, trimming new ones shorter and prying slightly so I could still insert pin into hole. Once through grip one part out to bend over and push the other end somewhat toward the hub.

[Scott Elkes]

I never had an issue with the original Rupp acorn nuts back in the early/mid 60s.

[Kurt Bogerman]

Thanks for all of your help, guys.

I was finally able to trim, bend into an arc, and drive in the cotter pins. It required more of a ham-handed approach than I usually expect when installing a cotter pin. I've learned that the original spindle design featured lock nuts w/o pins, so the spindles must have been drilled by a previous owner. Not being original, that explains the sub-optimal geometry of the situation.

[David Luciani]

none of the early karts were drilled for safety anything.
as experience got written in blood the rules expanded to safety wiring brake bits,rims and steering in place.

just about anything that prevents the nut from turning out enough to fall off should be acceptable as a stop.

on old karts with original axles and poorly drilled holes i've found camphering the hole a bit helps installation.
 if it's a loose fit thin shimming washers help make up the difference.
if you want a permanent fix cut the offending axle off and install a slightly longer axle in it's place. 
btw , what you did was fine.

[Al Hasenfratz]

It doesn't hurt to pin, wire or locknut everything else too. Or at least check all the fasteners frequently. Karts tend to shake themselves apart constantly. The heim joint bolts on my G/P rear frame section are frequent fliers.

[Kurt Bogerman]

It doesn't hurt to pin, wire or locknut everything else too. Or at least check all the fasteners frequently. Karts tend to shake themselves apart constantly. The heim joint bolts on my G/P rear frame section are frequent fliers.

Regarding locking hardware:  Most of the hardware I'm using is AN spec stuff from Aircraft Spruce, so it'll be ready to rock & roll.

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none of the early karts were drilled for safety anything.
as experience got written in blood the rules expanded to safety wiring brake bits,rims and steering in place.

just about anything that prevents the nut from turning out enough to fall off should be acceptable as a stop.

on old karts with original axles and poorly drilled holes i've found camphering the hole a bit helps installation.
 if it's a loose fit thin shimming washers help make up the difference.
if you want a permanent fix cut the offending axle off and install a slightly longer axle in it's place. 
btw , what you did was fine.

Yeah, thinking about replacing the axle, too.  It looks pretty shabby right now.

[ted johnson]

Just because nuts are self locking, and hardware is AN, NAS or MS, it still needs a drop of blue Loctite. Don't forget to clean nut and bolt with brake/carb cleaner or naphtha before applying the Loctite. I keep a container of Q Tips for cleaning internal threads. A fingernail and paper towel with spray brake/carb cleaner works for male threads. With studs, a drop of red Loctite on the male thread of the stud, and a small drop of blue on the nut end usually ensures the stud staying put when the nut is removed. TJ