My engine plans for this car have ebbed and flowed. I have been torn between building something on my original case, or changing the case. Originally I was planning a 2.5LS build on the original case, this needed replacement crank, rods, bolts, P&C, heads, MFI pump work etc, then I moved towards a 2.5SS build which needed all the same things but also a CW crank a 2.7l case (and all associated machining) and twin plugs.
I then realised that realistically this was far too expensive a build for me to ever be able to fund largely due to me needing to change pistons, cylinders, MFI pump, and heads (my 2.0 heads being no good for any larger builds). Also, I started to think that I would prefer to retain use of my matching numbers 69 case and 69S heads & pistons etc rather than mothball them for eternity on a shelf. I rather liked the idea of an "old-speed", period, almost 911R style build
The compromise build I have come to is simply to drop a 70.4mm crank in. This will give me about 2.15l and up my compression from ~9.8 to ~10.4 simply from additional swept volume. This gives me significant cost savings and retains the originality that I like. I will keep the matching no's case in the car. I can re-use my original 2.0S P&C, and heads which all appear in good condition. I can also retain my MFI pump as I think the small change in displacement can be adjusted for rather than getting it custom modified by some expensive workshop. Given the lightweight 80mm pistons Im sure I can run stock 2.7 rods and bolts and run them upto the 7.5k rev limit of the 70.4mm crank rather than laying out for pauter rods and ARP bolts etc... really the only expensive part of this build is twin plugging it which I had already mostly bought the components for second hand (I love a bargain). There is more than you would think to this, a Distributor and head modifications obviously, but also a second CDI+ box (+mount), second CDI wiring loom, second coil (+mount), a set of 12 HT leads, lower rocker cover modification (or buying fancy off the shelf ones), all kinds of lead holders, etc
Since I stripped the engine down and sent off all of the relevant parts to the local machine shop, (case, crank, rods, heads etc) I have been doing other bits and pieces I can get on with.
Made the mount for 2x CDI+ boxes
Mounted 2x Coils
Made the rod and chain holder tools
Modified the lower rocker covers for twin plugs
Modified the cylinder baffles
