Al alloy for pony motor bearings

6061 T6 aluminum or 936 bronze would be a good choice.

I was told by a Metallurgist here in Oz who tested those pilot motor bearings that old alloy pistons melted down out of a Toyota Landcruiser were almost the exact same metal, apparently it has a high tin content, like 1.8%, to give it the hardness. He worked for Toyota here in Oz, so was used to testing their metals, hence his suggestion was based around using old Toyota pistons from a scrap yard.

I could use one of your bearings made 40 thou undersize, I had a pilot motor crank here ground a year ago and the only way to save it was to cut to 40, Cat can still supply up to 30 thou undersize and I've bought a few of those already, just make sure you get your crank crack tested, the failure rate seems to be around 50% from what I've seen here in Oz.
Regards
Mike
.

I used 6061 when I made my bearings. My crank was also a bit beat. I used a 1/2 wide air belt sander on a custom toolpost in the lathe to clean the crank up. After I polished the crank I made the bearings to fit...never even thought to check if you could get new ones but after hearing the prices I would have made them anyway. I been breaking magento rotors and gears and thought the bearings I made were having issues but it ends up the flywheel was loose...the nut was finger tight. Probably dumbness on my part as I only had one part of the lock ring bent on the nut side, I had not bent it to the crank side.
Old Magnet FYI...the gear lash looked good all the way round so I got lucky. The little beast fired right up today and sounded/run just as good as the day I finished rebuilding it. Still have to put he dash, battery box, hood etc. all back on but I run the diesel for about a half hour today. After making the tapered 'plug' I was amazed how fast the broach cuts the keyway. I have had that old keyway broach set for a while but this is the first time I used it.

I was told by a Metallurgist here in Oz who tested those pilot motor bearings that old alloy pistons melted down out of a Toyota Landcruiser were almost the exact same metal, apparently it has a high tin content, like 1.8%, to give it the hardness. He worked for Toyota here in Oz, so was used to testing their metals, hence his suggestion was based around using old Toyota pistons from a scrap yard.

I could use one of your bearings made 40 thou undersize, I had a pilot motor crank here ground a year ago and the only way to save it was to cut to 40, Cat can still supply up to 30 thou undersize and I've bought a few of those already, just make sure you get your crank crack tested, the failure rate seems to be around 50% from what I've seen here in Oz.
Regards
Mike
.

Mike,
That would be the beauty of making them, a guy could make sizes Cat doesn't supply...I wish I could find .040 rod bearings, the crank out of my original pony is ground .030 on the rods & one journal is buggered up again, where the rod came loose. The mains on that one are in good shape, & ground .020.

rjh-I don't know what process they used to build up this crank, but it didn't work so great. When I pulled the gear & seal washer out, I found a big flake of metal, looked like a piece of pounded-out rod bearing. Couldn't figure out what it was until I saw the flywheel-end journal was just starting to flake a little. Realized then the big flake was from the gear-end, that journal was worn down to the point it will take .020 to clean up...the clearance was about 1/16", plus the bearing was moving in the case, making almost 1/8" of end play.

Reddawg, thanks-good to know someone has use 6061 & had good luck...

Hi Team,
it is not the first time I have had a crank ground the minimum odd sized amount to clean up and then re-babbitted--using a soldering iron-- and machined the bearing shells in a jig made from an old con-rod.
Keep at it boys, there is more than one way to skin these Cats.
Cheers,
Eddie B.

Were you able to use a larger electric iron or was it a larger soldering copper heated with a tinsmith's furnace or a gasoline plumber's torch? Did you use old scrap bearing babbit or new material? I'm also wondering at what temperature does "common" babbit become workable?

Thanks, Daron

Hi Daron,
I used a smallish electric soldering iron (sorry I do not know the wattage as I have had it for some 35 or 40 years, from memory it has about 3/8" dia. bits in it) so hopefully I did not run a chance at overheating and destroying the Babbitt qualities.

I used old Babbitt melted out of other Ford side valve V8 engine bearings, this was an old side valve Ford V8 truck engine that had run No's 1+2 big ends of the early full floating style.
As the rods were cactus and I only had 2 good rods from a later precision style(steel backed shells) engine so I modified the crank to pressure feed just No 1+2 big ends. The others were OK and so were left.
There are places here in Australia that will re-Babbitt bearings so there must be some over in the good old USA

Before you all get twisted this engine was blown up years before and removed from a Canadian Ford Blitz truck crane and was deemed scrap.
It probably sat outside for 40 years as was heading for the scrap bin.
Dad said "it's beyond fixing, even as a display engine"
I wanted to get it going again--Dad was not amused, but, was eager to show it off to all and sundry after it was done and ran sweet as a nut.
Mike Meyer has seen and heard this thing run at Echuca Steam Rally recently.
A mate bought it and enjoys the same reaction from younger people who have heard of these engines but never seen one.
Cheers,
Eddie B.

Eddie, is that the same V8 that were put in some Fergs? Does it have a water pump?