will i get more hp if i bore 30 over

[shelbycobra]

will i get a few more hp if i bore my cobra engine 30 over

 

[no_slow_svt]

minimal if any.

 

[IUP99snake]

Let's say, just for an example that your car makes 281 HP to the wheels. It's currently a 281 cubic inch engine. Dividing 281 HP by the 281 cubic inches shows us that the motor makes 1 HP per cubic inch.

Boring the motor 30 over adds about 2 cubic inches of displacement (281 to 283CI when bored 30 over).

Boring out the motor 30 over with no other mods holding everything else constant, the motor will make roughly 2 extra HP because we calculated that in the current configuration, it made 1 HP per cubic inch, and it now has 2 extra cubic inches.

With more modifications (power adder for example), this HP gain is amplified. Let's use No-slow-svt's car as an example, it makes 664 HP to the wheels. 664 / 281 inches = 2.3629 HP per cubic inch. Adding 2 cubic inches by boring out the motor would add roughly 4.75 HP.

My point. Boring out the motor for the purpose of added displacement is not a cost effective mod. You'd have to increase the bore size significantly larger than 30 over to add enough extra displacement to add enough HP. Case in point, the new Boss 302 modular blocks that have a larger bore to create 302 CI instead of 281. That's 21 extra Cubic inches, or 21 HP over a stock motor making roughly 1 HP/CI, or 49.6 extra HP in the case of No-slow's motor which makes 2.3629 HP/CI. (holding everything else constant)

Homer

 

[cliesch22]

bump up compression and bore out and you will gain horsepower

 

[01SVTSnake]

Doesn't .030 over bring a 4.6 to 286ci?

 

[kxt]

.030 is about 15 human hairs in size. That small amount of extra bore diameter will net you a small, probably not noticeable gain.

 

[Brutal Metal]

And in some cases you could lose HP depending on the type of piston used, hence throwing a 8.5 in instead of 10.5!

 

[droptopsnake01]

Let's say, just for an example that your car makes 281 HP to the wheels. It's currently a 281 cubic inch engine. Dividing 281 HP by the 281 cubic inches shows us that the motor makes 1 HP per cubic inch.

Boring the motor 30 over adds about 2 cubic inches of displacement (281 to 283CI when bored 30 over).

Boring out the motor 30 over with no other mods holding everything else constant, the motor will make roughly 2 extra HP because we calculated that in the current configuration, it made 1 HP per cubic inch, and it now has 2 extra cubic inches.

With more modifications (power adder for example), this HP gain is amplified. Let's use No-slow-svt's car as an example, it makes 664 HP to the wheels. 664 / 281 inches = 2.3629 HP per cubic inch. Adding 2 cubic inches by boring out the motor would add roughly 4.75 HP.

My point. Boring out the motor for the purpose of added displacement is not a cost effective mod. You'd have to increase the bore size significantly larger than 30 over to add enough extra displacement to add enough HP. Case in point, the new Boss 302 modular blocks that have a larger bore to create 302 CI instead of 281. That's 21 extra Cubic inches, or 21 HP over a stock motor making roughly 1 HP/CI, or 49.6 extra HP in the case of No-slow's motor which makes 2.3629 HP/CI. (holding everything else constant)

Homer

Cliff notes:

NO

 

[IUP99snake]

Cliff notes:

NO

Cliff notes to the previous cliff notes: Keep in mind that there are other factors that come into play here. Increasing displacement via larger bore vs. longer stroke will affect HP in different ways throughout different parts of the powerband. A displacement increase will also affect HP depending on the induction setup, cams, power adders, and whether or not they can support the extra flow from the extra displacement. My explanation was basically a "holding all else constant" scenario. But as we all know, there aren't many constants.

So, DropTop, why don't you educate us on why you disagree with me. I'm easily convinced and I admit I'm no genius when it comes to these things. But "NO" doesn't really do a good job of getting your point across...

Homer

 

[hi_po_heads]

Cliff notes to the previous cliff notes: Keep in mind that there are other factors that come into play here. Increasing displacement via larger bore vs. longer stroke will affect HP in different ways throughout different parts of the powerband. A displacement increase will also affect HP depending on the induction setup, cams, power adders, and whether or not they can support the extra flow from the extra displacement. My explanation was basically a "holding all else constant" scenario. But as we all know, there aren't many constants.

So, DropTop, why don't you educate us on why you disagree with me. I'm easily convinced and I admit I'm no genius when it comes to these things. But "NO" doesn't really do a good job of getting your point across...

Homer

i may have misunderstood but, i beleive "NO" was a summary of what you stated and basicly means no you will not gain noticable hp by .030 over

 

[droptopsnake01]

i may have misunderstood but, i beleive "NO" was a summary of what you stated and basicly means no you will not gain noticable hp by .030 over

:banana:

 

[D's01Snake]

Cliff notes:

NO

:lol1:

 

[19mustang95]

Doesn't .030 over bring a 4.6 to 286ci?

i believe it does.