Would the compression increase if a cylinder was bored from 3.875 to 3.937 inches? this is not third gen related, sorry, but a friend is building his 250 straight six up from his 78 camaro LT, and got a bit confused (as did I). thank you!

 

If all else remains the same, yes it will but not significantly IMO. Probably about .2 if all else remains the same cc-wise.

 

OK, thats what I was wondering. He will be putting a 292 crank in (4.125" stroke, I think), so thats gonna raise compression, even with shorter rods.

 

Yes, that only yelds a 0.28 change in compression ratio.

 

Building up an inline 6, thats different. I'd like to hear how that runs.

 

As would I! I'll try to get sound clips of it when he's done. He's starting out with a really trashed 250 (I mean, when he pulled the head off, he found a little plastic ring, similar to those around the cap of a oil bottle, in the chamber). He is throwing a 292 crank in there, and it was bored out .062" totalling 306.5 CID!! Thats insane! If that was an 8, man, he'd be looking at 408 CID with that bore and stroke...crazy engine he's gonna have...