2.8/3.1/3.4 engine rebuilds

Guest · Post by **Guest** » Tue Jan 08, 2002 11:58 am

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.

Guest · Post by **Guest** » Tue Jan 08, 2002 12:52 pm

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??

Guest · Post by **Guest** » Tue Jan 08, 2002 1:41 pm

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.

Guest · Post by **Guest** » Tue Jan 08, 2002 8:49 pm

So these numbers are specific to the iron blocks. Thank you for clearifying that.

Guest · Post by **Guest** » Tue Jan 15, 2002 9:41 pm

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?

oldadmin · Post by **oldadmin** » Tue Jan 15, 2002 11:34 pm

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.

Ribz80 · Post by **Ribz80** » Wed Jan 16, 2002 12:49 am

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.

Guest · Post by **Guest** » Wed Jan 16, 2002 1:42 pm

hey Ribz... sorry about that. i read the post a little to fast i guess. i am glad that i have it cleared up.

Ribz80 · Post by **Ribz80** » Wed Jan 16, 2002 2:34 pm

No harm, no foul:)

Guest · Post by **Guest** » Wed Jan 30, 2002 9:44 pm

I thought Norm had a 2.8 bored and stroked to a 3.2? Is he just crazy?

Ribz80 · Post by **Ribz80** » Wed Jan 30, 2002 10:12 pm

Norm had a 2.8 but when he rebuilt it he went to 3.1l of displacement then bored it to 3.2l

Guest · Post by **Guest** » Fri Feb 01, 2002 6:41 am

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?

Ribz80 · Post by **Ribz80** » Fri Feb 01, 2002 1:14 pm

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.

Chris88CL · Post by **Chris88CL** » Fri Feb 01, 2002 4:26 pm

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

Guest · Post by **Guest** » Mon Feb 04, 2002 12:46 pm

Okay, thanks. Good stuff. What does "over mean, though?

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