Modifications

[Aussie Mike]

Hi Craig,

How's your car coming along? I saw it back in Ian's workshop a while back.

Just doing some math on the LS1 parts available from the various manufacturers and I got some interesting figures.

I know the race block can be bored and taken out much further. but it would be interesting to see how far you can bore and slieve the standard aluminium block. There are pistons listed for 4.130" bore and a pin height for 4.0" stroke. Cola make a 4.0" stroke crank and this combo would make a 429 Cube (7.030L) LS1.

The next step would be to try the Cola 4.125" crank and build a 442 Cube (7.243L) motor. Big block cubes but aluminium small block weight. The whole thing would weigh around 180KG (396 Pounds).

The 383 (6.276L) combination looks like the easiest to build. That's just dropping in the 4" crank and using the standard 3.905" bore. I believe COME are working on a 4" crank here in Melbourne and they are doing forged H beam rods. I think the 4" crank and some longer 6.2" rods (up from 6.125") and the pistons with the pin height to suit would be the go. The longer rods would help maintain the rod stroke ratio with the 4" crank and you wouldn't need to bore the block. The motor would be under square but the LS1 is a bit light on for low down torque anyway. This is probably the bigest cube combo with out having to bore or slieve or use the race block. Since the race block works out to about $16K down under so it's out of reach of a meer mortal like me.

Cheers