Let’s get to the engines starting with the smallest and cheapest candidates

D16Z6, D16Y8, D15B7: If you have one of the lower and cheaper civic models, IE The Cx, Dx, Lx and If you're looking for a cheap power increase while still maintaining stock gas mileage then the possibility of swapping in one of the higher model civic engines is right up your alley. The D16Z6 is the SOHC 5th Gen. Si and Ex engine pushing 125hp @ 6600 rpm and 106 lb.-ft of torque @ 5200 rpm. The D16Y8 is the 6th gen. SOHC Ex engine pushing 127hp @ 6600 rpm and 107 lb.-ft of torque @ 5500 rpm. These are extremely easy to find since allot ppl swap them out in favor for more expensive engines. They bolt in like stock and the whole package could be had for hundreds (You might even find someone who’s recently swapped who would basically give away their engine). Let's say you want something cheap but you could work on for possibly turbo or nitrous? The D16Y8 is cheap and the pistons are the exact size of TT Supra pistons. They could substitute for forged versions and work just as well for a turbo upgrade. Be warned though as the D16Y8 has a particularly bad Rod to Stroke ratio at 1.52. I also suggest the B15B7 which is the 5th gen. Dx and Lx engine pushing 102hp @ 5900 rpm and 98 lb.-ft of torque @ 5000 rpm. If you have a 5th gen. Cx and you’re in need of the cheapest upgrade, this motor could be for you. Again you could probably find it for less than $500.
  
B16A1, B16A2, B16A3: If you need a little more power and have the money, the Civic Si and the del Sol VTEC engine are possibilities. They are all DOHC 1.6 liter engines pushing 160 hp @ 7600 rpm and 111lb.-ft of torque @ 7000 rpm. The A1 is the pre-obd engine that came with a cable transmission and various other pre 5th gen. items that need to be dealt with when considering the swap. The reason I point this out is because all 5th and 6th gen. civics came with hydraulic tranny's so think twice about this one. The upside is the cheap price. The A3 is the OBD1 engine out of the del Sol Vtec. These older models can be had for cheaper than OBD2 models and have upgraded various things such as hydro trannies. These are a perfect choice for the 5th genners. The A2 is the 99-00 Si engine. Same as the A3 only this one came with an upgraded OBD2 emissions system that is mandatory for all 96+ civic swappers. The B16A1 could be had for around $1200. The B16A3 could be found for about $2000-$2500 and the newer B16A2 could be found for around $2500-$3000.

They all lack a sufficient amount of torque due to their small displacement but their small mass and a bad ass R/S ratio of 1.74 allows them to rev to astronomical proportions. They also all have a HUGE aftermarket support. The only thing I don’t like about this particular swap is that this seems to be only one people think of. Whenever they want to swap engines, they all go for the B16. Don’t get me wrong, it’s a great engine but there are other engines out there to consider. I’ve even known people to be disappointed because they expected more. That’s what this article if for
 
B16B: Often regarded as the best 1.6 liter engine in the world, the JDM Civic Type R engine is the rarest of them all. Producing a whopping 185hp @ 8200 rpm and a reasonable 120 lb.-ft of torque @ 7600 rpm and being naturally aspirated, it is technical marvel. It was only available on the 1999-2000 Civic Type R and having one imported will run you easily into the $6000+ range. But you will be WELL respected and large thief magnet when ppl find out. If you have the money and like spending it on high octane gas for your 4 banger, why not?

B17A, B18B1: The B17A could be found on the 92-93 GSR producing 160hp @ 7600 rpm and 117 lb.-ft @ 7000 rpm. The B18B1 is the later model Integra LS, RS, and GS engines. They don't offer huge power outputs at 142hp @ 6300 rpm and 127 lb.-ft @ 5200 rpm, But they can be had for very cheap as they are plentiful and not really sought after by many people. The exception being for the B17A as it did have greater power output but they can still be had for cheap as they are generally older and in worse shape compared to the newer B18’s. Anyone of these should still offer a cheap, reliable power upgrade for your small civic. Anyone of these engines could be found for under $2000. The downside to these cheaper engines is their Rod to Stroke ratio. The B17 isn’t that bad but the B18B1 has a R/S ratio of 1.54. This does considerably reduce the maximum possible power output from these engines. But if you don't plan on turbocharging this engine past 15 psi or letting it rev to 11,000 rpm, then it should meet your modest power needs.  


B18C1: Probably the most highly sought after swap candidate, this powerful little engine came on the late model Integra GSR and produced a hefty 170hp @ 7600 rpm and 128lbs-ft @ 6200 rpm. It is rather expensive at around $3000-$3500 and they are a little on the rare side considering everyone wants one, but a simple swap and your pocket rocket will be pushing high 14's with a stock engine. Even more by adding the small bolt-ons. And greddy has a bolt on intercooled turbocharger kit that'll give around 240 wheel hp. Which should put you deep into the 13 second range, possibly high 12's. This is the most desired swap candidate.


B18C5: This naturally aspirated wonder came on the late model Integra Type R and produced an even greater 195 hp @ 8100 rpm and about 130 lb.-ft of torque @ 7500 rpm. This is even more highly sought after than the GSR engine. And would in fact be more popular if it wasn't for its $5000+ price tag. But if you could afford it, there are few engines that would be as painless and give you the fastest performance available for the civic. This regarded as the naturally aspirated wonder because it does well producing large amounts of power without the need for snailshell's. Although a turbocharger can be bolted on to this bad-boy, it's generally not recommended, as this is a very high compression engine. If you were to used forced induction on such a high compression engine, you would either have to build it accordingly, have a REALLY good engine management system ($$$) or watch it blow up on the first run. The C1 is better suited for forced induction and would cost less in the long run.