Does the bore centerline intersect the crank centerline?

[pfredric]

Does the cylinder bore centerline intersect the crankshaft centerline on our Turbo motors?

 

[Chuck Leeper]

???

Does the cylinder bore centerline intersect the crankshaft centerline on our Turbo motors?

It better.:biggrin:

 

[pfredric]

It better.:biggrin:

Had my block bored 20 over. 1, 3 and 5 didn't clean up, the original bore wasn't touched at the bottom on the non-thrust side. 2, 4 and 6 were like that too, just not as bad. Looks like a lower case "n" where the boring didn't touch the original hole.

My machinist is a chebby guy, mega experience boring, but not much with Buicks. He says 30 over ought to get it.

I'm just wondering if there was something my machinist and I didn't know about. I've heard that the Buick V6 is an "offset" block. I believe it refers to the postioning of the cylinders with respect to each other side to side, not with regard to the crankshaft centerline.

Thanks for answering.:smile:

 

[TurboDave]

Had my block bored 20 over. 1, 3 and 5 didn't clean up, the original bore wasn't touched at the bottom on the non-thrust side. 2, 4 and 6 were like that too, just not as bad. Looks like a lower case "n" where the boring didn't touch the original hole.

My machinist is a chebby guy, mega experience boring, but not much with Buicks. He says 30 over ought to get it.

I'm just wondering if there was something my machinist and I didn't know about. I've heard that the Buick V6 is an "offset" block. I believe it refers to the postioning of the cylinders with respect to each other side to side, not with regard to the crankshaft centerline.

Thanks for answering.:smile:

Yes, offset means the cylinders are offset from their rod throw, but in the fore and aft plane. Thrust/non thrust planes should be dead nuts on.

 

[pfredric]

Yes, offset means the cylinders are offset from their rod throw, but in the fore and aft plane. Thrust/non thrust planes should be dead nuts on.

Yep, confirmed.

Rich Lasseter's May/June 2007 GS-Xtra included an article from Tom Shea that explains what "offset" means: "The production blocks found in our cars are "Off Center" meaning that the cylinder bores are offset from the centerline of the crank rod journal by .120."

I haven't yet figured out in which direction, but I speculate that it will switch side to side.

Anyone know which direction?

I imagine I might be able to see 1/8th" difference on the pistons side to side, but haven't looked.

 

[CTX-SLPR]

The offset is always towards the counterweights on the crank throws. I think its 1 Forward, 2 Back, 3 Forwards, 4 Back, 5 Forwards, 6 Back. I could be wrong with order but they are paired so that one bank, the offset is towards the front of the block and the other towards the back.