Help,
I am trying to remove the prop from a saito 100 mounted on a H9 P-51. The problem is I can't turn the prop nut (spinner adapter) without turning over the engine. Holding the prop no longer helps as the prop is now loose enough that the shaft rotates inside the prop. With the cowl in the way, albeit loosened, I can neither get the glow plug out to jam the piston with a dowel. nor can I get close enough to the prop flange to hold it from turning when I attempt to turn the prop nut. I don't have much hair left as it is, but I am ready to pull what's left out!!! Do I have any recourse other than cutting the cowl off......I REALLY don't want to have to do that! I am open to any and all suggestions/advice on this little quandry I have gotten myself into. Thanks in advance.
Ken

You could cut the prop...

Very thin string or fishing line. See if you can wrap it between the prop washer and prop or between the prop and prop flange. Be sure to pull tightly as you are wrapping it around. Should create enough tension to lock the prop in place again so you can use it while you are loosening the nut.

Go ot the hobby shop and buy a piston stop tool. The car guys use them a lot. It screws into the plug hole and prevents the motor from turning over. Should be fine for what you want.
Dennis

One technique I've used sucessfully is to put the wrench on the nut perpendicular to the prop then while holding the prop, strike the wrench with the handle end of a screw driver. The impact will usually crack the nut loose.

can you get to the thrust bearing or is there a cowl in the way? if you can, wrap a couple layers of electrical tape around it and then clamp on with a needle nose vise grip. (I've had to do this myself a couple of times...)

Take the engine down to a local shop, and have a mechanic hit it with a 3/8
"butterfly" air impact wrench....and a 6 point socket. [sm=thumbup.gif]

....the nut will be loose in .0012376 seconds....

FBD.

I vote for Flyboy Dave's method. Its amazing what a pneumatic tool will do.

Ken:

The air wrench idea of Dave's is probably the easiest, but if you can get to the engine air intake you can fill the cylinder with oil, a deliberate hydro lock. You can then clear it by turning the engine backwards.

Bill.

Dave,
The pneumatic wrench sounds like a good idea. I have one, never thought of using it. I'll need to find a deep socket to get past the spinner adapter and on to the nut. Thanks for the suggestion I will give it a spin...so to speak!
Ken

Remove glow plug.........bring piston up the top.......pack string into the glow plug hole .......make sure you leave several inches hanging out so you can remove it. Turn prop nut to loosen.....string will pack tight and not allow crankshaft to turn..............prop nut will come off very easy.......no mess and no damage to anything.

none of you guys read the original post? he ain't got access to the plug...

i'm all for the impact driver. i've got an electric one by makita that i use for driving big wood screws and just recently discovered that it's also great for taking old bike engines apart. took the flywheel and clutch nuts right off without using anything but my hand to hold things still.


dave

Your right! I missed that!

SUCCESS!!! Thanks for all the input. After thinking about the impact wrench suggestion I thought I would try one thing before I used pneumatics. I took my 18volt cordless drill and just tightened the chuck down on the spinner adapter much like you would do with a drill bit in the chuck. I then hung on to the prop and let rip with the drill. Worked like a champ! That drill had ample torque to break the nut free and the chuck had no problem hanging on to the spinner adaptor/prop nut. Needless to say I am very happy. Again thanks to all for the suggestions, it really got my mind going in the right direction.

Ken