My del sol comes with a 1.6L SOHC, 5 speed manual. What would be a good upgrade engine wise that would fit this pattern?

The 1.6 SOHC is a D series, so any kind of 'upgraded' engine should be a B series (if you want it to fit without changing more than your motor mounts). The B16 (Civic/Sol Si or SiR) is a stout powerplant with a lot of potential. The B18 (Integra) is my motor of choice. The B20 (CRV) seems to be a popular choice these days because of it's torque. Any one of these motors will fit snuggly and give you a lot more go.

b16 or b18

I have a '90 Integra XSi, and it has a B16A. this motor will scare you crappless when you hit 6000rpms. this is my favorite motor due to the parts avalibility, power, v-tec, and potential. I am looking to swap a B20 block into mine. since roughly our cars are the same. My base model (RSi) came w/ a D16 and yours came with a D16, my upper model (XSi) came with a B16A and yours came with a B16A. May I recomend that you buy a totled Del Sol Si from a junkyard. then you would have all the mounts, linkages, fuels system componets, emissions would be matched, and you could fix minor other frawls in your car. A totled Del Sol Si w/ B16 runs for about $1500

Your V-8 can't touch this sweet Honda Integra XSi....