CA20ET LPG project help
Hi fellas my first post after a long wait to get on these forums which are 8v
rich and always a mystery since there have been some issues with member
approval in the past stopping me from reading the important info here.
I would like to build a punchy LPG turbo CA and have the following
in mind so far for the build (most parts purchased):
CA20e block with undecided pistons.
CD20e crankshaft suits ca18det oil pump (to be lightened and re-balanced)
Prepped Z22 149.5mm c-c rods to suit 53mm BE of CD crank
(lightened, shaved each side, shot peened and balanced 562gsm each)
ORC single plate fly/clutch setup suits CD20 8 bolt flange type
Garrett T28BB disco
Chasing 200hp atw with excellent of response no lag if possible.
8v head modded
Camshaft (piper?) undecided
Im chasing torque with big midrange & 7000rpm redline so 8v is likely.
Thinking of using heatproof jet coated stock exhaust manifold with T28BB and
equal length short runners with custom plenum and mid mounted TB.
I was thinking of welding up the inlet ports and exhaust valve and run
motorbike sparkplugs that allow me to have more meat on inlet ports
to be able to raise the angle and increase the size without worrying
about sealing issues on bolt up flange area. Also the LPG doesnt really
need 2 plugs per chamber as it burns really well with 1, so welding
up exhaust plug (all Australian 8v heads are 8 plug heads here) and
reshaping the chamber to increase swirl from inlet across where the
exhaust plug side would be which interferes with the swirl usually and
causes turbulence that sends mixture more onto the cylinder walls.
Also thinking of heatproof coating the chambers after porting and
reshaping to help keep temps a little lower using LPG.
Intercooler size is not decided but would like to keep inlet temps decent.
Also what ARP bolts should I run? as the ca20 block bolts are thinner
not as deep into the block and not an off the shelve item (searched).
Also thinking I might not need a crank girdle or main ladder brace
as used to stiffen the ca18det block? or best use one? if so it will have
to be custom made to suit the 88mm stroke and counterweights.
Im not interested in the 16v head they are 10kg heavier than the 8v
and I like the space Im saving in the engine bay of my datsun b10
will look more nostalgic too with chrome rocker a-la-s13eater
Last edited by datsober; 12-01-2013 at 07:48.
|