2.8L bore

[calisonic]

so i am rebuilding my '88 2.8 corsica. iv'e rebuilt (and bored) a few engines but i really want to bore this one out as much as possible. so my questions are:
a. how far can i bore it safely/how thin of a wall won't work (i've never bored an aluminum block).
b. how high can i raise the compression with taller pstons (or can i) without causing any ECU problems or the like.
thanx.

[calisonic]

also, would Part # 10048649 work from http://60degreev6.com/showthread.php?t=24997

[ForcedFirebird]

You can use the later 3400 heads that have larger ports, yes.

I am unaware that GM had an aluminum block in the 2.8 format, I think you may be mistaken.

I've seen .080 over on the iron block 2.8.

[86euro]

Do you want to bore for more cubes? A 3.1 rotating assembly may be a better option.

[calisonic]

Do you want to bore for more cubes? A 3.1 rotating assembly may be a better option.

yes, i am going for cubes but im trying to get the most possible, hopefully more than 3.1 or 3.4.

[bjornmk1]

there was a 2.8 mpfi in the early 87-89 or 90 cars
forced bird,they had dis ignition and aluminium heads.

bjorn

[bjornmk1]

max.safe)bore size on a 2.8 or a 3.1 is about .60over
you could go to .70 but than you would be pushing your luck if you ask me.

gr.bjorn

[ForcedFirebird]

there was a 2.8 mpfi in the early 87-89 or 90 cars
forced bird,they had dis ignition and aluminium heads.

bjorn

a. how far can i bore it safely/how thin of a wall won't work (i've never bored an aluminum block).

He said aluminum block.

[calisonic]

there was a 2.8 mpfi in the early 87-89 or 90 cars
forced bird,they had dis ignition and aluminium heads.

bjorn

yeah mine is the 1988 2.8l

[calisonic]

max.safe)bore size on a 2.8 or a 3.1 is about .60over
you could go to .70 but than you would be pushing your luck if you ask me.

gr.bjorn

so you mean like a 3.0L total?


btw, my mistake its not an aluminum block.

and one more Q.
im relativley new to the 60 degree v6, could someone pleae fill me in on what years were gen I II or III?

[sharkey]

the best thing to do would be to have a look at the family tree, located in the menu bar on the left.

it is not safe to go as big as 3.9l. im sure what he meant was .060" overbore is safe, .070" is pushing it. imho, with our motors, .060" is pushing it, i wouldnt run anything more than .040" overbore.

[bjornmk1]

eh...060-.070 inch ..OKAY !!!

no sweat man.

[calisonic]

ok well that putts me at a 3 liter but what about compression?

[ForcedFirebird]

ok well that putts me at a 3 liter but what about compression?

Put a 3.1 crank and overbore pistons. Boostedrs has a 3.3l (.060 over iirc) and is an alcohol twin turbo with 12.7:1 compression, but he is having starter problems with all that comp.

[lampy]

For the 3.1 conversion you need the crank and pistons for a 3.1. Just built one with .060 pistons havent put the numbers in the CR calculator yet but it is around 3.2 or 3.3l.Its an easy way to gain cubes.