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6.2 N/A to 6.2 turbo internal engine specs

3500GMC

3500GMC

What T F, over
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More specifically, ring gaps, piston to wall clearance, deck height, head gaskets.

Ring gaps:
If one had a choice on ring gap, using an over size ring set, file fitting each cylinder, what would be a good ring end gap to shoot for? (6.2 turbo)

What's the N/A 6.5 ring gap compared to the 6.5 turbo?

Is there a GM spec for a turbo 6.2? (banks)

Piston to wall:
There is a .001" bigger finished bore for 7&8, should the same apply to a 6.2? (I'm thinking yes)

Deck height:
How could one determine if a block has been decked? Looking for a factory spec here to determine this, I think? Measuring what I have to compare it to...

Head gaskets:
As far as aftermarket, what are the differences in 6.2 & 6.5 head gaskets? .010" thicker are available through Fel-pro to help with a decked block.

There seems to be confusion on the BORE SIZE affecting compression. I've read on here of some guys thinking a BIGGER bore LOWERS compression... This can't be, can it? Think swept volume of a cylinder.

I'm needing to get the compression 'right' for a turbo 6.2. I don't want to butt a ring or blow head gaskets down the road.

Thoughts?
 
I'm looking for some experience with 'getting it right' VS. just slapping parts together and throwing a turbo on it. Anybody can do the latter. I know that as boost and fuel levels go up, so does heat and thus rings take a beating as they expand. So I guess 'how much' is the question when going N/A to a turbo 6.2.

Maybe I should call Mr. Banks or Bill Heath.

...and I have to respectfully disagree Ak, bigger bore = higher compression. Shorter rods with the piston at the SAME location at TDC will net the same static CR as longer rods...We're not changing the stroke- or length of rod for that matter. Longer and shorter rods are not in my equation.
 
Bigger bore does increase the CR. Shorter rods will decrease the CR. compression ratio is all about volume of the cylinder including combustion chamber at bdc vs the volume at tdc. Moving the piston crown lower in the bore at tdc means lower cr.
 
I. am. not. changing. rod. length.

Since we know CR is a ratio of volume of a cylinder at BDC vs. TDC, with the rod shorter, means the piston is lower @ TDC bore AND lower @ BDC ALSO. So... therefore 'ratio' is the same.

But like Ak said, the quench area is the kicker.

I need specs guys, read post #1. Ring gaps, stock deck heights, things of this nature. Usually a ring mfr. will include a sheet spec'ing how much gap per inch of bore per type of fuel, boost, induction etc. There is nothing of the sort with new 6.2 / 6.5 rings, at least the Sealed Power versions I have.

I can't be the only sorry bastard that's file fit rings for a turbo 6.2. :hihi:
 
If I had that info it would be yours. I was just commenting on the area I thought I could help in. I know there are a few guys on here with manuals. I'm sure they will pipe up eventually.
 
Thanks Ak, I know you'd help out.

I guess I'm being a little impatient.

I have some time to murder, so I may as well tear into the spare IP. That's the last stone I've not turned. What an adventure.
 
3500GMC said:
Since we know CR is a ratio of volume of a cylinder at BDC vs. TDC, with the rod shorter, means the piston is lower @ TDC bore AND lower @ BDC ALSO. So... therefore 'ratio' is the same.
Click to expand...

You're statement makes no sense at all. Think about what you say in the first sentence and then think about the second sentence. They don't fit together. THE RATIO CHANGES.
 
"lower @ TDC AND lower @ BDC ALSO" ....deleted the word 'bore'... shouldn't have been there.

Makes sense to me.

The Compression Ratio is a fundamental spec for an engine. Simply put, the ratio of a cylinder volume at it's largest point...compared to it's volume at it's smallest point. A ratio. Rods do not change static CR... They cannot shrink and grow each stroke to the point of altering CR.

Read up before turning this thread into a pissing match. All I was after was specs for a old junk 6.2.

I'm done here.
 
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