high compression piston kit
Nov 9, 2000 | 02:06 AM
#2
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Both.
The big-bore kit would require a new piston anyway, and if you are getting one, you may as well get a high compression piston.
However, a cam will probably make more difference than either, for a cheaper overall cost.
The big-bore kit would require a new piston anyway, and if you are getting one, you may as well get a high compression piston.
However, a cam will probably make more difference than either, for a cheaper overall cost.
Nov 12, 2000 | 08:57 AM
#4
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A big bore kit will increase the engine's displacement. Basically allowing the engine to consume more oxygen and fuel. The more oxygen and fuel an engine can burn the more HP you'll obtain.
Increasing the compression ratio increases cylinder pressure. Basically, squeezing the fuel and air into the cylinder head more than before.
Think of it this way, take an M80 firecracker, set it on the ground and light it. Boom right? Well set it inside a small coffee can (can top facing ground) Bigger BOOM. Why? Because you're containing the same explosion in a smaller area, which results in a more powerful explosion.
Also a higher compression ratio will burn fuel / air more effeciently. Remember though, any comp ratio over 10:1 will require a higher octane fuel. 93 octane would be the minimum for 10:1
Changing CAM specs (lift, duration, etc.) changes the affect of the intake and exhaust valves. A higher lift cam will open the intake valve more, which results in more fuel entering the engine. A higher duration leaves the valve open longer.
I'm sure you've heard a muscle car idle? It sounds real loapy or choppy. That's because the CAM is leaving the valves open longer (to increase fuel consumption) and if they are open longer, they will have to close faster so that the piston will not smack them, so they close abruptly. This is what gives a muscle car that type of idle.
There is your Engine 101 for today!
Increasing the compression ratio increases cylinder pressure. Basically, squeezing the fuel and air into the cylinder head more than before.
Think of it this way, take an M80 firecracker, set it on the ground and light it. Boom right? Well set it inside a small coffee can (can top facing ground) Bigger BOOM. Why? Because you're containing the same explosion in a smaller area, which results in a more powerful explosion.
Also a higher compression ratio will burn fuel / air more effeciently. Remember though, any comp ratio over 10:1 will require a higher octane fuel. 93 octane would be the minimum for 10:1
Changing CAM specs (lift, duration, etc.) changes the affect of the intake and exhaust valves. A higher lift cam will open the intake valve more, which results in more fuel entering the engine. A higher duration leaves the valve open longer.
I'm sure you've heard a muscle car idle? It sounds real loapy or choppy. That's because the CAM is leaving the valves open longer (to increase fuel consumption) and if they are open longer, they will have to close faster so that the piston will not smack them, so they close abruptly. This is what gives a muscle car that type of idle.
There is your Engine 101 for today!
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