chelle51501965

Someone just gave me a 289 V8 that is bored 40 over. I know what that means, but what is the difference going to be in performance? It's a 1965 coupe.
Thx, Chelle

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vshayes

maybe 2-3 hp

mdvaldosta

thats me ^ there, wife was still signed in.... doh!

Crazyfast50stang

What does 40 over mean? what does it change? I know what a bore is I just don't know the number that come with it.

mdvaldosta

It means your cylinder bore and piston are .040" larger than stock. A 289 has a stock bore size of 4.000 inches, so a 40 over would have a bore of 4.040"

Crazyfast50stang

ok thank you

WNDSOR

theres no mod better than cubes, it should help, i'm not sure but it should be around 292-295 cubic inch now

callmecobra

im gonna have to disagree...FI

WNDSOR

fuel injection? um....you can have more cubes and fuel injection...

mdvaldosta

well ok FI is more important than cubes for horsepower - thats a given. But there is no replacement for displacement, as they say. But going .040 over, or any other overbore isnt gonna really amount to much - maybe 3 or 4 hp at best. Now when you start stroking for 40-50 more cubes - now thats will really help performance.