maaaaackle

iTrader: (1)

Hey guys, im putting together my 13b. Im cleaning my front cover and see these lines throughout the front cover that look like cracks. Is this normal? Maybe theyre casting marks?

j9fd3s

iTrader: (3)

casting marks

need-a-t2

iTrader: (9)

yup. Ugly, but completely normal.

mazdaverx713b

iTrader: (91)

I also agree that the marks in question are casting marks. This is extremely common not only on our front covers but on many many other manufacturers front covers as well. I've even seen casting marks just like these when disassembling a Toyota 6spd automatic transmission. It can catch you off guard at first and then you get used to seeing them.

TonyD89

iTrader: (10)

Yep, it's from the die cast mold, it's called "Heat Checking". They'll run it until they start getting breakouts.