LS2 Compression ratio for a blower?
Thread Starter
Teching In
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LS2 Compression ratio for a blower? Hello,
I am getting ready to build an LS2 for a Magnacharger. What compression ratio do you all recommend? I may even use a Kenny Bell if they every release it?
Thanks.
Phillip
I am getting ready to build an LS2 for a Magnacharger. What compression ratio do you all recommend? I may even use a Kenny Bell if they every release it?
Thanks.
Phillip
I'd probably go 10.0 CR with a Magna if I were doing it all over. More CR and less boost. Its not about all-out max performance, so less boost is fine. Either way you end up with the same output.
Thread Starter
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MTI is recommending 9.5:1 with the Magncharger. I am going to put everything in but the blower. By then, the Kenny Bell should be out and I can decide Kenny Bell or Magnacharge. It looks like I can not wait. I have to build the motor for the blower I am going to choose.
I am trying to understand something:
You add the proper amount of fuel and air, close the valves, compress it, light it fire, and bang. The more fuel and air, the bigger the bang. Also the more compression, the bigger the bang (to a limit). If you get too much compression the fuel and the air light before the spark plug fires.
So why do people lower the compression of the engine, so the can cram in more air, effectively raising the compression ratio back up? What does this make more power than a N/A motor with high compression pistons?
Thanks
Phillip
I am trying to understand something:
You add the proper amount of fuel and air, close the valves, compress it, light it fire, and bang. The more fuel and air, the bigger the bang. Also the more compression, the bigger the bang (to a limit). If you get too much compression the fuel and the air light before the spark plug fires.
So why do people lower the compression of the engine, so the can cram in more air, effectively raising the compression ratio back up? What does this make more power than a N/A motor with high compression pistons?
Thanks
Phillip
TECH Apprentice
Joined: Jan 2004
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From: Frisco TX (Dallas Area)
Mainly to prevent/minimize detonation. Boost means higher *dynamic* compression (cylinder pressure) and usually some more heat - kaboom before the plug fires. You can either lower the *static* compression or add higher octane gas (among other things) to prevent detonation. HTH 
Thread Starter
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Let me see if I can answer my own question. I know this is over simplified, but let me try.
If I have a n/a engine, then to get the compression up, it have to bring the piston closer to the head. Lets say 1/2" from the head to the piston.
With a blower, I can get the same compression with 1" from the head to the piston. Same compression level, twice the volume of air and fuel.
Is this correct?
If I have a n/a engine, then to get the compression up, it have to bring the piston closer to the head. Lets say 1/2" from the head to the piston.
With a blower, I can get the same compression with 1" from the head to the piston. Same compression level, twice the volume of air and fuel.
Is this correct?
