Prop trust -

[Jim Allen]

Jim,

Where can I buy it.

I checked MatWeb but they don't list any vendors.

Rod Geraghty

Rod,

This stuff may not be available anymore. It was used to make sleeve & thrust bearings for the crawler transporter that moved the Columbia shuttle vehicle.

call; Bearium Metals of Canada, LTD.

225 Centre Street East

Richmond hill, Ont.

Tel: 315-524-2200

good luck.

 

[Charles Perdue]

Thanks Mr. Jim, keep the good information coming. That is what this forum is supposed to be about.

I don't run sleeve bearings in my struts. I run ball bearings. I start with a shaft of S 7 tool steel, size of .250 and machine this down to .187 except for .750 on one end that I drill out to .185 for the cable to soldered into.That way you don't have to mickey mouse the cable end to fit into a smaller hole and weaken the cable. I use Sta-Brite solder to fasten the cable into the stinger. I use 3 standard bearings and 1 flange bearing. 2 standard bearings to the front and 1 standard and 1 flanged bearing to the rear. This arrangement is kept seperated by a spacer. Tha OD of the bearings is a snug push fit inside of the strut in case of a cable failure so that you don't loose the prop and stinger. I run this on my 20 and 40 boats. I drill an oiling hole into the side of the strut. Very free running and almost bullet proof. I am sure that there are a lot of other ways of accomplishing this set up. This is just the way that I do mine.

I hit a LARGE turtle in my 20 boat that just about destroyed the boat. It bent the stinger at the drive dog, wrapped the prop around itself, mutilated the stuffing box and twisted the cable in two but it all stayed together.

 

[Jim Allen]

Thanks Mr. Jim, keep the good information coming. That is what this forum is supposed to be about.

I don't run sleeve bearings in my struts. I run ball bearings. I start with a shaft of S 7 tool steel, size of .250 and machine this down to .187 except for .750 on one end that I drill out to .185 for the cable to soldered into.That way you don't have to mickey mouse the cable end to fit into a smaller hole and weaken the cable. I use Sta-Brite solder to fasten the cable into the stinger. I use 3 standard bearings and 1 flange bearing. 2 standard bearings to the front and 1 standard and 1 flanged bearing to the rear. This arrangement is kept seperated by a spacer. Tha OD of the bearings is a snug push fit inside of the strut in case of a cable failure so that you don't loose the prop and stinger. I run this on my 20 and 40 boats. I drill an oiling hole into the side of the strut. Very free running and almost bullet proof. I am sure that there are a lot of other ways of accomplishing this set up. This is just the way that I do mine.

I hit a LARGE turtle in my 20 boat that just about destroyed the boat. It bent the stinger at the drive dog, wrapped the prop around itself, mutilated the stuffing box and twisted the cable in two but it all stayed together.

Sounds good Charles. Since I use solid shafts, I drive the thrust up into the engine. The inner races of both engine ball bearings are fastened together, therefore there is no problem carrying the propeller thrust load. The thrust is transfered from the male ball & pin to the female slotted piece via a full hard thrust washer. The O-1 shaft in the strut has the ball & pin machined directly on it. After full hardening & tempering the .250 dia shaft is ground between centers. A pre drilled cone shaped hole is used to hold the splined set screw for the pressed fitted drive dog. This shaft cannot be bent or broken even when striking objects that break the full hard beryllium copper prop.

Jim

 

[dave roach]

Jim

So you like to thrust on your engine bearings.The weight of the boat plus the thrust of the prop means more thrust side load on the bearings.

Dave

 

[Jim Allen]

Jim

So you like to thrust on your engine bearings.The weight of the boat plus the thrust of the prop means more thrust side load on the bearings.

Dave

Yes Dave, but as I stated in my post, I am applying that thrust to both front bearing inner races simultaneously. I can do this because the two inner races are mechanically fastened together. They are also mechanically fastened to the crankshaft. In ALL production engines this thrust would only be applied to the inner race of the FRONT MAIN BEARING! My system with a full hardened steel front end allows the axial end play to be set on a cold assembly at .003 to .004 by using steel shims. At elevated running temperatures the axial play does not change because all the parts involved are made of steel. I did not develope this system. It was developed by the Metkemeijer brothers in 1976 & used in their world record holding team race FMV engines.

Jim