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2.8/3.1/3.4 engine rebuilds

Posted: Tue Jan 08, 2002 11:58 am
by Guest
The following was a list compiled with the use of many V6 manuals and experienced mechanical individuals. Here is the list:


Rebuild on a 2.8:

Bore = 89
Stroke = 76
"Over = std
CC's = 2836
Liters = 2.8

Bore = 89.5
Stroke = 76
"Over = .020
CC's = 2868
Liters = 2.9
Result = Safe

Bore = 90
Stroke = 76
"Over = .040
CC's = 2900
Liters = 2.9
Result = Safe

Bore = 90.5
Stroke = 76
"Over = .060
CC's = 2933
Liters = 2.9
Result = Safe

Bore = 91
Stroke = 76
"Over = .080
CC's = 2965
Liters = 3.0
Result = Risky

Bore = 91.5
Stroke = 76
"Over = .100
CC's = 2998
Liters = 3.0
Result = UNSAFE

Bore = 92
Stroke = 76
"Over = .120
CC's = 3031
Liters = 3.0
Result = UNSAFE


Rebuild on a 3.1:

Bore = 89
Stroke = 84
"Over = std
CC's = 3135
Liters = 3.1

Bore = 89.5
Stroke = 84
"Over = .020
CC's = 3170
Liters = 3.2
Result = Safe

Bore = 90
Stroke = 84
"Over = .040
CC's = 3206
Liters = 3.2
Result = Safe

Bore = 90.5
Stroke = 84
"Over = .060
CC's = 3242
Liters = 3.2
Result = Safe

Bore = 91
Stroke = 84
"Over = .080
CC's = 3277
Liters = 3.3
Result = Risky

Bore = 91.5
Stroke = 84
"Over = .100
CC's = 3314
Liters = 3.3
Result = UNSAFE

Bore = 92
Stroke = 84
"Over = .120
CC's = 3350
Liters = 3.4
Result = UNSAFE

Rebuild on a 3.4:

Bore = 92
Stroke = 84
"Over = std
CC's = 3350
Liters = 3.4

Bore = 92.5
Stroke = 84
"Over = .020
CC's = 3386
Liters = 3.4
Result = Safe

Bore = 93
Stroke = 84
"Over = .040
CC's = 3423
Liters = 3.4
Result = Safe

Bore = 93.5
Stroke = 84
"Over = .060
CC's = 3460
Liters = 3.4
Result = Safe

Bore = 94
Stroke = 84
"Over = .080
CC's = 3497
Liters = 3.5
Result = Risky

Bore = 94.5
Stroke = 84
"Over = .100
CC's = 3534
Liters = 3.5
Result = UNSAFE

Bore = 95
Stroke = 84
"Over = .120
CC's = 3572
Liters = 3.6
Result = UNSAFE

I hope that this information serves it's purpose to educate everyone in what to do and not to do with their rebuild.

2.8/3.1/3.4 engine rebuilds

Posted: Tue Jan 08, 2002 12:52 pm
by Guest
The 3.1L in the Indy Pace car "track cars" were bored to 92mm. Why would this be considered unsafe if Chevy themselves did it??

2.8/3.1/3.4 engine rebuilds

Posted: Tue Jan 08, 2002 1:41 pm
by Guest
Quote (IndyMark @ Jan. 08 2002,12:52)The 3.1L in the Indy Pace car "track cars" were bored to 92mm. Why would this be considered unsafe if Chevy themselves did it??
The Indy Pace Car had an aluminum block that could be bored to 91 / 92 mm with no harm unlike our iron stock blocks.

2.8/3.1/3.4 engine rebuilds

Posted: Tue Jan 08, 2002 8:49 pm
by Guest
So these numbers are specific to the iron blocks. Thank you for clearifying that.

2.8/3.1/3.4 engine rebuilds

Posted: Tue Jan 15, 2002 9:41 pm
by Guest
TAZ- according to "Ribz 80" all berettas have aluminum blocks, what is the real story?

if we have aluminum blocks shouldn't we be able to bore to .080 or .100 over?
also what is 92mm equal to... .100 or .080?

2.8/3.1/3.4 engine rebuilds

Posted: Tue Jan 15, 2002 11:34 pm
by oldadmin
Quote (matty0071999 @ Jan. 15 2002,9:41)TAZ- according to "Ribz 80" all berettas have aluminum blocks, what is the real story?

if we have aluminum blocks shouldn't we be able to bore to .080 or .100 over?
also what is 92mm equal to... .100 or .080?
Wrong all Berettas have iron blocks and alluminum heads the aluminum block can be purchased from GM.

2.8/3.1/3.4 engine rebuilds

Posted: Wed Jan 16, 2002 12:49 am
by Ribz80
Huh!!! I never said that.  I said all Beretta's had aluminum heads and the only one that had an aluminum block was the REAL indy pace car.

2.8/3.1/3.4 engine rebuilds

Posted: Wed Jan 16, 2002 1:42 pm
by Guest
hey Ribz... sorry about that. i read the post a little to fast i guess. i am glad that i have it cleared up.

2.8/3.1/3.4 engine rebuilds

Posted: Wed Jan 16, 2002 2:34 pm
by Ribz80
No harm, no foul:)

2.8/3.1/3.4 engine rebuilds

Posted: Wed Jan 30, 2002 9:44 pm
by Guest
I thought Norm had a 2.8 bored and stroked to a 3.2?  Is he just crazy?

2.8/3.1/3.4 engine rebuilds

Posted: Wed Jan 30, 2002 10:12 pm
by Ribz80
Norm had a 2.8 but when he rebuilt it he went to 3.1l of displacement then bored it to 3.2l

2.8/3.1/3.4 engine rebuilds

Posted: Fri Feb 01, 2002 6:41 am
by Guest
What did he change that made it safer?  I thought the block was the same for both the 2.8 and 3.1.  Is it a heads thing?

2.8/3.1/3.4 engine rebuilds

Posted: Fri Feb 01, 2002 1:14 pm
by Ribz80
The block is the same but a 3.1 will come with larger bore and the cylinder walls to accomadate it.  It can handle an overbore to 3.2l but a 2.8l just doesnt have the material to do it.  Its physically the same block on the outside, thats about it.

2.8/3.1/3.4 engine rebuilds

Posted: Fri Feb 01, 2002 4:26 pm
by Chris88CL
Its physically the same block on the inside too.
The 2.8L and 3.1L have the exact same bore.  The only difference is in the stroke.  Norm put in a 3.1L crankshaft and bumped his 2.8L up to a 3.1L without having to touch the bore.  Then he bored it out to make it a 3.2L instead of a 3.1L.
Theres not enough material to keep a 2.8L crank and bore the cylinders out to a 3.2L.  You need to stroke it and then bore it.  There WAS however one difference in the blocks.  Im not sure when or which platform it was on, but there was a 3.1L block with a reinforced lifter area.  

Chris
ICQ: 10833817
AIM: Chris88CL
lezarch@hotmail.com

2.8/3.1/3.4 engine rebuilds

Posted: Mon Feb 04, 2002 12:46 pm
by Guest
Okay, thanks.  Good stuff.  What does "over mean, though?