Phillip Lawrence

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

LSs1Power

iTrader: (5)

For pump gas use 9.1-9.6 C/R for a MagnaCharger and 8.1-8.6 C/R for KB.
For race gas use 10.1-10.5 C/R for MagnaCharger and 9.1-9.6 C/R for KB.

Nine Ball

iTrader: (38)

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.

Phillip Lawrence

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

TeeKay

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

Phillip Lawrence

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?