how to tell if a motor is bored over?

[shoooter]

hey guys i have a 340 out of someone elses 71 cuda. I believe the motor is bored .60 over how can i tell? The heads are off the motor and there is a cracked piston. not sure if it is any good or not I will need to get it checked out. Now if it is already bored .60 over will it even still be good?

[cudabob496]

gotta get a micrometer and measure.

normal bore 4.04 inches, so .060 inches over would be 4.1 inches

[72cudamaan]

measure the bore with a bore gauge, or measure the piston skirt about 1 inch above the tail. If .060 over
and needs to be bored, it's useful life is pretty much over with. The cost of sleeving 8 cylinders gets pretty extreme.
I've done it for customers before but when you add 8 sleeves plus decking the block afterwards, most just buy another block.

[Strawdawg]

Look on the piston for a part number.

[Haddixj]

If you want a cheaper option use a set of cheap dial calipers from Harbor freight it measures to the thousandth. Also pistons usually will have the over bore on top of them like 30 or 60. What the Vin btw?

[HP_Cuda]

Put on a karnac hat, stare at the 340 intently for 36 hours then open the envelope!!!

 

[shoooter]

If you want a cheaper option use a set of cheap dial calipers from Harbor freight it measures to the thousandth. Also pistons usually will have the over bore on top of them like 30 or 60. What the Vin btw?

motor 71 340 stamp number 1B378831. Also found trans OC141196.

[Haddixj]

 Swing and a miss for me. I will be on the lookout for 1b345796 340 block I have the matching 4spd trans

[shoooter]

Looks like its bored .60. Might be out of luck with this one

[Chryco Psycho]

not good , you may want to look at a 360 short block , lots around & cheap , could build a 408 stroker with a 360 block