Eagle crankshaft

[Minella]

Moper,
The crank truly broken. The machinst had to remove material due the balance be internal and the engine is using I beam rods about 600 grams.
The mains wheren't alligned, same stock.

 

[moper]

Hmm. I've never been able to internally balance a cast crank without mallory in both counterweights. If that was the case, there may be more to this defect than just metalurgy. That's wierd. What do the cap parting lines look like? Main studs or bolts? What about the main bearings of the other saddles?

 

[fishy68]

Moper I just had the machine work done for my stroker using a Eagle cast crank, Scat I beams, and Wiseco Pro-tru forged pistons and much to my surprise my machinist didn't have to add any weight to internal balance it. In fact he had to drill some out of the counterweights cause the crank was heavy. The pistons with pins only weighed 480 grams which I'm sure contributed to it being light enough to internal balance easy.

 

[moper]

Ah. I overlooked the I beam part in both those.. I normally use H or stoke rods. That would probably be the difference.

 

[lilcuda]

Is there a casting irregularity at 3 o´clock position? can you make a detail photo? want to take a closer look.

greets Michael

That's the oil hole for the rod journal.

 

[Robzilla]

My Eagle cast crank balanced internally also, the light rotating assembly caused the crank to be heavy and the machinist had to take weight from the crank.

 

[mopar4406bbl]

I talked to a machinist last week and was told that he kept records for 2 years, and of the china stuff Scat was the best. American made is better than off shore, but most Scat products are ok.

 

[myasylum]

I just got that same Eagle crank now too!! I wish I would have read this first! Urgh!
Wish me luck!

 

[2 Darts]

That is a strange break. The break seems to go straight across the side of the journal. It's almost as if something kept the two sides of the mold apart when the casting took place. I agree with all that quality control should have picked it up. If I had an Eagle crank ready for install now, I'd have it magnafluxed first.

Aircraft fasteners from China were a big problem about twenty years ago. The issue was too much porosity and out right misrepresentation of fasteners as being Grade 8 quality. The grain in the pictures of the casting seems to be too coarse for this application. Is it just me? Any metalurgists on this site?