Milwaukee Midget

[fordboy628]

That retainer in your pic is a rough looking fellow!  Many stress risers on a deal like that. 
 

Yes, that's one of the "used" retainers that has been "ridden hard and put away wet".    And as a stock piece, it wasn't very pretty to begin with . . . . .

Now it is permanently "retired" . . . . . .
 
F/B

[nickleone]

Chris,
Are you going to clean up the scoring on the rocker arm?
The scars could lead to some stress/failure of the rocker.

Nick

[Milwaukee Midget]

Chris,
Are you going to clean up the scoring on the rocker arm?
The scars could lead to some stress/failure of the rocker.

Nick

Nick, I wish I had the time.  It looks worse than it actually is, and I do have a spare, so on this one, I'm taking the calculated risk.

My morning started at 6:45 with three hours of drive time, to set up PA for the Waupun Truck-N-Show . . .

http://waupuntrucknshow.com/events.html

More chrome than Sturgis.

Normally they have a lift for me to use, but because I'm insistent on being at Bonneville no later than Friday, I requested they move my install up to Monday instead of Wednesday.  The lift was there, but the guy who runs it wasn't, so I spent most of the day hanging paging horns from the side of an ice rink building and the light towers of a baseball diamond on a fiberglass ladder with aluminum rungs in the rain.

I got home at 9:00 PM this evening.

Fordboy requested I post a pic of the cracked collar.  I'll let him explain what we're looking at, because I'm tired.



Oh - Happy Birthday, Jack!

[fordboy628]

Chris,
Are you going to clean up the scoring on the rocker arm?
The scars could lead to some stress/failure of the rocker.

Nick

Yes, that is true.   The bigger problem however, is that the rockers are hard anodized, not just color anodized.   Smoothing off the scoring will remove the hard anodizing and some of the surface strength of the part.   It's a "catch 22", da**ed if you, da**ed if you don't.

Like Chris said: "Time for a calculated risk".     Or like I say: "Time to make a choice, and walk the line".

There isn't a perfect solution in the timeframe available . . . . . . . .
 
Fordboy

[Jack Gifford]

Chris- thanks for the 'shout'. I sure hope no more "gremlins" appear to you on this outing- go FAST!

[fordboy628]

Fordboy requested I post a pic of the cracked collar.  I'll let him explain what we're looking at, because I'm tired.



Oh - Happy Birthday, Jack!

Happy Birthday Jack!    x2      Many happy returns!

What is hard to see on the photo of the broken retainer is the propagation site, very small fatigue cracks at the bottom of the keeper taper.   Most of the rest of the failure is the resulting overstress cracking (Yield) through the center of the part.    At the very top, there is a tiny bit of instantaneous failure (UTS failure) where the part finally separated into 2 pieces.   It is interesting to speculate on the total number of cycles over which this failure occurred.   I'm guessing less than a few hundred, which is a very low number in service . . . . . .

I'm going to see if I can get a photo through a 10 power lens to show more detail, but that probably will not happen until after SpeedWeek.   It is important to note that a better view of the failure at higher magnification might result in a reassessment of the failure process.   Same result, but maybe the crack started in some different location.    This is where a 10x  or 100x view would help.

I'd be more concerned if the plan were to continue to flog the tractor motor into the future . . . . .

BUT, after next week, it's 'Back to the Future' for the 'MM'!!    Well, back to the 1980's at least . . . . . . .    and that's a warp speed jump from 1930 . . . . . 

And the tractor motor gets pensioned off to some Formula Junior from the 1950's or 60's, a proper retirement . . . . .
 
Fordboy

[grumm441]

So that's after Goggles breaks it then?
G

[fordboy628]

So that's after Goggles breaks it then?
G

Grummy,

Possibly . . . . . .

Let's just say I have "some concerns"     

If you have an Australian equivalent of "Keeping your fingers crossed", I think everyone would appreciate it if you would do it.   Can't hurt, can it?
 
Fordboy

[Milwaukee Midget]

So that's after Goggles breaks it then?
G

If it breaks, there will be no finger pointing.
 
This engine is a design that has been stretched well beyond what the engineers had planned for it.  We've mitigated many issues, lived with others, and got stung by a few.

We've discovered where the questions are, and we'll keep tabs on the issues we can keep eyes on, but if it breaks, it's simply going to be a matter of whose turn it was to break on them.

It is what it is - let's see if it's enough. 

[Milwaukee Midget]

Hey, Mark -

So I'm going through my spares and I find my spare thermostat.

But then I find my other spare thermostat.

 

Mark, did you put the thermostat back in the car on Sunday? 

[fordboy628]

Hey, Mark -

So I'm going through my spares and I find my spare thermostat.

But then I find my other spare thermostat.

 

Mark, did you put the thermostat back in the car on Sunday? 

Duuuhhh, NO!!   Didn't see it anywhere, so I guess I forgot it!!    Crap!!

Sorry . . . .
Alzheimersboy

[manta22]

It looks to me as if there is a second small crack in the right hand part and also maybe some evidence of porosity in the material.

Regards, Neil  Tucson, AZ

[Milwaukee Midget]

It looks to me as if there is a second small crack in the right hand part and also maybe some evidence of porosity in the material.

Regards, Neil  Tucson, AZ

Tell you what - I'll bring 'em along.

I intended to offer them up to the Dumpster of the Salt Gods, but Fordboy wants me to keep them as mementos of my good fortune.

I don't know - seems Brit cars are engineered to leave parts behind.

Rumor is that the engine out of the 1954 Austin Healey Streamliner is buried somewhere in Utah . . .

http://www.austinhealey.com.au/bonneville.html

I ain't gonna look for it . . .

[Stan Back]

How in the helll do you find time to source all these obscure postings?  I thought you worked 27 hours a day.  Do you know Mike?

[Milwaukee Midget]

How in the helll do you find time to source all of these obscure postings?  

Pathetic, isn't it?
I guess I'm a geek.  

Oh, and Fordboy, the spare spare thermostat is back where it belongs.