Overbore

[killab443]

I just got a used rebuilt block and dont know of the overbor the guy didnt know. On the pistons slightly engraved it says .75 exactly how much over does that make the pistons. I know it cant be .75 over because that seems like too much./ There 2g pistons on 1g rods

 

[92redman]

Well, if the .75 is infact talking about the overbore, that would be .75 mm or .030" over. You won't know until you check the piston with a micrometer though.

 

[ADrewzki]

I just got a used rebuilt block and dont know of the overbor the guy didnt know. On the pistons slightly engraved it says .75 exactly how much over does that make the pistons. I know it cant be .75 over because that seems like too much./ There 2g pistons on 1g rods

.75 would be entirely too much. 0.075 might be a little more believeable.

 

[killab443]

thats why i posted to ask. .075 over would make the walls too thin

 

[b00stAdict]

thats why i posted to ask. .075 over would make the walls too thin

i know this is an old post but to answer that the ".75mm" is the size of the piston. the ".30" is the bore of your motor.

 

[daplatano91]

Looking to up your post count by reviving 6 year old threads?

 

[standard235]

i know this is an old post but to answer that the ".75mm" is the size of the piston. the ".30" is the bore of your motor.

No.

.75mm=.030"

So the piston was marked as a .75mm overbore or .030" overbore.

The bore is actually 85mm, or 85.75mm in this case, which comes out to 3.3760" rounded to the nearest ten-thousandth.

 

[Misterbeechy]

Looking to up your post count by reviving 6 year old threads?

hahaha thats funny

 

[g4ebguy90]

the service spec is .040. Anything over that would be a junk engine just so u know from now on it isnt at all .075 over.