Why an undersized crank in a 383 ?

[71 Bee Man]

Hi guys,

just curious....my 71 383 has an engine stamp which is a maltese cross, and an "X" next to it.

Now, I've read that this refers to 0.010 undersize bearings and a 0.010 undersize crank.

My question is, why would they do that ? What does it do ?

Peter

[Nacho-RT74]

Engine was already machined

[John_Kunkel]

Most likely there was a minor flaw or an "oops" while grinding the crank so, rather than scrap it, they just ground it undersized.

[71 Bee Man]

Most likely there was a minor flaw or an "oops" while grinding the crank so, rather than scrap it, they just ground it undersized.

OK.....so does the undersize have any effect on the motor at all ?

[c00nhunterjoe]

Spun mine at high rpm with a 4 speed for over 16 yrs on .010/.010

[alfaitalia]

Surprised you did not run out of fuel !!!

[HPP]

Most likely there was a minor flaw or an "oops" while grinding the crank so, rather than scrap it, they just ground it undersized.

OK.....so does the undersize have any effect on the motor at all ?

No effect at all.

[John_Kunkel]

OK.....so does the undersize have any effect on the motor at all ?

Lots of folks run BB cranks with .125" undersized mains and .050" undersized rods.

[c00nhunterjoe]

Surprised you did not run out of fuel !!!

Did that 1 time... did the walk of shame..... never again. Lol.