I have a good portion of my engine disassembled waiting for aftermarket parts to either be availible, ordered, or delivered. I didn't want to put it all back together until I had all the parts. Will 3 - 4 months without a start damage the engine? What preventative actions can I take?

BTW, my engine has ~5000 miles on it and I changed the oil for the second time with Mobil 1 before disassembling it...

Thanks.

 

I figure nothing well happen to your engine. But your battery will be dead, the oil and fuel will go bad in 3 - 4 months of not being used.

Drain the oil and fuel and un-plug the battery. Remember the radio code will go on when you reconnect the battery.

 

The biggest enemies are likely to be corrosion and dust. If possible use a lay-up or assembly oil to coat all the dis-assembled parts and cover everything else. It's probably a good idea to wrap everything possible in plastic bags and draw as much air out as possible. Just don't forget how to put it all back together
The battery should be ok if you trickle charge it regularly, but disconnect from the car first, or you'll blow the alternator. It's also worth jacking the car up and leaving on axle stands, so that the tyres don't sag.
Other possible problems are locking brakes and clutch. If it's damp, they will rust and bond together. The brake can be left off, but there's a lot of debate on the clutch. Leave it and it could stick, hold the clutch pedal down with a piece of wood and risk straining the seals and return spring. Take your pick