Inner cam bearing spun and cracked

[mbskeam]

hello, well it seems that after 2100 miles on rebuild my inner cam bearing spun. it took a piece of the case with it and cracked it to the pinion race. then the pieces went into the oil pump. I think this happend last monday rode tues and then fri after fixing my intake leak. went to ride to work sat got about 1/4 from home and idot light is on , looked and no press on gauge.shut it down and pushed back home . went in to pump and found that it sheard the oil pump main drive key, pulled cam cover off and when Iwent too pull cam that sick feelling in my gut hit me.as the cam bobled all around, this sucks. pulled off S&S oil pump and the piece of case and bearing pin busted 3 teeth off the return gears but the key did not shear like it shuold have. got out the cam it got hot as the end is kinda blueish and bearing stuck to it. well I pulled out engine to take it back to the guy who rebuilt this . will see if he works this out or not .
History: I dumped oil after int. startup then 50 miles then 500 then 1500 and babyed it on the back roads for the first 500 and didnt really beat on it, I thought It was ready for reg riding now. it sounded okay before the pump shut down. well the hunt is on for a 48-53 right hand case if the welder at work does not think he can fix this (welding next to the steel race and all) i have seen the blown up cases he has welded up so he prob will know.all I can say is this SUCK .
mbskeam

ps on the horse post they wrote about cold welding from creekside welding, I have hot heard of this before. Jack, cotten?

[Jack_Hester]

Mbskeam -

I really don't know about the guys at Creekside. Never done business with them. I have major repairs like this done by Don Sullivan at Head Hog, Inc., in Ohio. Don't give up on it, until one of the specialty shops condems it. Cotton has his sources, that he can recommend. He may be able to fix you up. We'll see what his response is. Keep us informed.

Jack

[Cotten]

I farm out everything I can these days, but no farther away than I have to.

I am not aware of "cold" welding. I'm no welder.

Remove the race prior to TIGing up the cam bore. Re-install it before your mill-meister sets up to re-bore the cam hole.
He can index from another (good) right case.

Distortions from welding may require that the race be re-honed and re-fit for rollers.

The worst case scenario is if your welder encounters radiating cracks that open up with heat. In one circumstance I installed a large stainless pipe plug which was then milled and bored as a housing for the cam bushing. (The machine has seen many seasons of service since then: probably stronger than the original.)

[mbskeam]

hello, well I showed the welder and I do have radiating cracks(4) one down 6:00 one at 11:00 and two more at 2:00 and 3:00 about 3/4" out bored from boss area. he said we could bore it and put a plug like cotten said. my rebuilder is going to work with me but as sturgis is here I am going to have to wait till he gets back. hopfully I can get out of this with out paying out a ton of $$$$$$$$$$ just some gaskets, rings, new gears for pump, cam as the end is cooked, and later model torrington bearing. we think this happened due to higher valve spring press. than the older style bushing could handle. but just a therory
mbskeam

[Cotten]

I would vote against the needlebearing update.

Springpressure would not have caused the overheating of the journal.

[mbskeam]

hello, why not do the torrington? got bushing off the end of cam and I measure less than.001 diff. preaty tight but this could be after the thing has spun and done the evil. who knows.? I know he reamed my hole out as I saw the plate being un bolted from the case when i droped off same parts. I read in the rivera catalog that bushing cams and needle brg. cams are diff. dia. /.8112 to .8125 bushing./ or.8122 to.8125 rollers so as I look in all the diff. parts books none say any thing about this so what do you guys know about this?
mbskeam
see pics in repop sec. under panhead

[Cotten]

Yes, there is a thou difference.

Note that you will have to shoulder the bore if using a bearing, and that the case will have to be carved upon for the tanged thrust washer.
Its a lot of trouble just to make the assembly weaker, and wear out quicker.

Bushings can be fit to a worn cam. Bearings cannot.

I suspect your spun bushing was a matter of endplay, not bushing fit. I happens to the best of us. (I, too, have had problems even after setting up everything carefully. Particularly the with the bearing design, as the thrustwashers are less tolerant of lack of lube upon start-up.
Although the book cites a smaller minimum, I now usually aim for .010" endplay. Cams expand more in length than their journals do in diameter.

[mbskeam]

hello, they say a picture is worth a thousand words.trying out same new stuff. I did check my end play,(for my own piece of mind) it was about .007 with oil and assy lube on it, I think it would be about .009 .010 dry. I think I might have caused this to happen to the bike. it had only been running about 4 min when some women in her suv tryed to take me out. turning right in front of me with another car at my 7:00 and no time to make an appointment to stop with old brakes so I hit the gas WFO to shoot between them. and as I kept on the gas as it was a lot of fun I heard a squeal that I thought was from the clutch as it had been slipping before. well I guess I know better know to let it warm up before flogging it to hard . look at photos to see what my heavy hand probably did! this has been going in my mind for awhile as
I dont have much else to do but think about this
mbskeam

[Cotten]

It is human nature to try to point a finger at a cause,...but machines obey their own rules.

Your endplay isn't a smokin' gun, if your measurement was before the catastrophe. And afterward, the measurement means little.

And your heavy-handed hotdoggin' shouldn't have been enough to do it either, although it was possibly the straw that broke the camel's back.

Perhaps there was a slow burning fuse, but your evasive maneuvers just fanned the flame. The burnt journal would not have happened instantaneously.
As is so often the case, you must just do the repairs and hope the gremlins come out in the wash. Most often they do.

But some extreme circumstances/possibilities come to mind, and something to inspect for while disassembling:
Could the endplay on the crank assembly have allowed the crankpin nuts to peen the bushing or knock the end of the cam askew?

Look for clues as you take it apart: Did any other parts of the motor get hot? (has the rod sideplay gotten tighter, has the pinion roller fit gotten snug? Any burnt thrustwashers? etc.)

Any chunk o' stuff between teeth of the camgear/pinion gear?

Let us know what you find with a magnifying glass.

[sleeper]

MBskeam,
All things considered. You're Lucky you made it thru that incident w/out the suv taking you OUT!!
You know what I mean.

[mbskeam]

hello, I got the cases back here are some pics.





and I got the call today saying that the bottom end is put done .he should also have the heads done in a few days.and no I didn't find any thing in the gears as I looked over every thing .shafts and races looked purfect . yes Billy a lot of drivers in wash. get there licence to drive from a kracker jack box. I think driving with ones head up the nether region is not a good thing.Its time to start carrying 3/8 ball bearings .FLINK........CRACK maybe the next time they try and run over a some one on a bike they will remember CRACK !
mbskeam

[sleeper]

Mbskeam, your cases look like they will be OK.
When they put in the new cam bushing in the case, you might wanna put in a new one in the cam cover & put the cam cover on & have it line-honed to Dead-straight.
As the Damage &/or repair/welding may have distorted it, from Straight.
Wouldn't hurt a bit either, to bolt the case halves together empty & check the case races for Straight.
As the race looks like some heat got near it..
Now would be the time to be SURE...

PS: Ball-bearings are always handy to have.
Your area's not the only state giving out Driver Licenses from Cracker Jack boxes!!!

[Jack_Hester]

Mbskeam -

Billy's info is right on the money. And, I was especially bothered by the discoloration on the right main bearing race. It is easy enough for a shop to remove that one and install you a new one. Then, line-lap both of the mains, to make sure your line is true. I don't like color on races.

Jack