Eagle 4.250 Cast Crank Broken

[Rick Parker]

How about a Sprint Cup motor? That would make you pucker without the fear of breakage.

[D-CEL]

Eljaro,

I your rod journal arrived on Friday. I am sending it to my metallography lab this morning. I should have some answers later this week.

Jason

[ERA Chas]

Originally Posted by D-CEL

Eljaro,

I your rod journal arrived on Friday. I am sending it to my metallography lab this morning. I should have some answers later this week.

Jason

Six weeks past-what were the results and what is OP doing at this point?

[Eljaro]

Originally Posted by D-CEL

Eljaro,

I your rod journal arrived on Friday. I am sending it to my metallography lab this morning. I should have some answers later this week.

Jason

I am glad the journal arrived. I was wondering why it was taking that long. Let's see what comes out of the analysis.
And thanks for your effort, Jason.

[D-CEL]

Hey Eljaro, Chas and all

Sorry all for the delay, as this is a "G job", the paying customers have to come first. But rest assured we have accumulated some very interesting data in the 21.2hrs we have in it so far. I have asked that it be completed soon, we are shooting for the next two weeks. Our initial review suggests a machining defect in the fillet radius as the initiation point, However a problem also exists within the microstructure of the material. The combination of the two appears potentially fatal.
On the good side, if the data proves out, we should be able to offer a fairly accurate NDT acceptance model for checking the microstructure of the material before installation. Here is a hint for the sharp eyed!





Best regards
jason

[ERA Chas]

Originally Posted by D-CEL

Hey Eljaro, Chas and all

Sorry all for the delay, as this is a "G job", the paying customers have to come first. But rest assured we have accumulated some very interesting data in the 21.2hrs we have in it so far. I have asked that it be completed soon, we are shooting for the next two weeks. Our initial review suggests a machining defect in the fillet radius as the initiation point, However a problem also exists within the microstructure of the material. The combination of the two appears potentially fatal.
On the good side, if the data proves out, we should be able to offer a fairly accurate NDT acceptance model for checking the microstructure of the material before installation.

Well August is around the corner but I still feel there's value for all of us in the outcomes here.
Ejaro-you said you were moving to another resolution and build with Keith; has that happened?
Jason-what came out of the above procedures?

[Eljaro]

Originally Posted by D-CEL

Hey Eljaro, Chas and all

Sorry all for the delay, as this is a "G job", the paying customers have to come first. But rest assured we have accumulated some very interesting data in the 21.2hrs we have in it so far. I have asked that it be completed soon, we are shooting for the next two weeks. Our initial review suggests a machining defect in the fillet radius as the initiation point, However a problem also exists within the microstructure of the material. The combination of the two appears potentially fatal.
On the good side, if the data proves out, we should be able to offer a fairly accurate NDT acceptance model for checking the microstructure of the material before installation. Here is a hint for the sharp eyed!





Best regards
jason

Hi Jason,
any additional info regarding your analysis which I can pass on to Keith ?

I am ordering the new short block and would like him to take special care in the crankshaft selection. Your info may be helpful.
Thanks
Stefan

[ERA Chas]

Originally Posted by Eljaro

I am glad the journal arrived. I was wondering why it was taking that long. Let's see what comes out of the analysis.
And thanks for your effort, Jason.

Have you started another engine build? Or plan one?

[Eljaro]

Originally Posted by ERA Chas

Have you started another engine build? Or plan one?

Yes, but since I have some other financial priorities right now I have put it off for a few more weeks.
I told Keith I wanted a good one (a crank) which would not break and he says a RPM Steel 4340 crankshaft will do.
I hope he knows what he does.