So you want to swap out that puny 91 cubic inch weed whacker engine of yours and replace it with a fire-breathing DOHC? That’s cool. But which engine should you go for? The 5th and 6th generation civic owners are lucky in the fact that its bigger brothers were designed very similar to the civic in many ways. This allows the ability to transplant various other engines from other H-cars without too much fuss. Integra, Prelude, other civics, even the sport Ute CRV engines can be considered. In addition you can do more than just swap out the whole engine, you could take a Vtec cylinder head and put it on your existing engine or swap out the whole engine and THEN swap the head on that. The possibilities are many. To help you wade through this mess, First I’ll talk about the different engine choices, and then I’ll talk about head swapping choices and its benefits. I’ll get into the pros and cons of each to help YOU decide which choice is wise for you according to your courage, budget and power needs.First off I need to mention a few things. When looking for your possible swap candidate, have a plan and research EVERYTHING. Find out as much info from as many sources as you can find. Now when putting $$$ aside for the swap, put aside as much as the components costs (Engine, transmission, etc), add shipping if necessary, then add at least $1000 for small extra parts you might need and/or broken parts on the engine (PCV valves, distributor core, AC bracket, axles, shift linkage, new polyurethane mounts, etc), and finally calculate how much you’ll need to replace all the high wear components: Timing belt, plugs, oil pump, clutch, etc. Believe me, it’ll cost ALOT less to replace them now than if they break after you’ve installed the engine. You should buy the helms manual for the engine you plan to get to get a complete run down of all the technical stuff. AND before I forget, remember that your stock cooling system will most likely need to be upgraded in one way or the other to cool the new bigger engine. And plan on the safe side to be without the car for at least 2 weeks. It shouldn’t take more than a weekend of work but something ALWAYS goes wrong. As we Hispanics say: “Dress yourself in patience” and expect the worst and you’ll be fine.As for exactly what you need to complete the entire swap, unfortunately it changes slightly with each engine considered, which is why it’s extremely important to research exactly what you need, but here’s the general list:
The Rod to Stroke ratio: This topic gets very complicated very quickly. Basically it’s the ratio of how long the rod is compared to the length of the entire rod stroke. The perfect ratio is 1.75. If the ratio is off, it means that the rod is not using 100% of it’s momentum to compress the air and gas mixture. It’s using more energy to push against the sides of the cylinder walls than to compress the fuel mixture. This is normally not too bad because things are very well lubricated in your engine. But when you change certain aspects of the engine, in particular increasing the ECU fuel cutoff point or going forced induction, the imperfect R/S ratio will cause more stress on the engine block and could eventually destroy it. A good R/S ratio also ensures long engine life. For a more in-depth look into the R/S ratio check out the following site: http://victorylibrary.com/tech/crod-c.htm
OBD stands for On Board Diagnostics. Most every modern car has a version of OBD and it’s basically an engine monitoring system. It consists of many different sensors in strategic locations that monitor various aspects of the engine’s performance. Some examples of the sensors are O2 sensors that monitor the air to fuel mixture, the throttle position sensor that senses how open the throttle plate is at any given moment, and intake temperature sensor that monitors the temperature of the intake air. All of these sensors are monitored by the ECU, the car’s brain monitors the OBD system and changes variables according to pre-programmed specifications. There are currently 3 versions of OBD and each version gets progressively more complex and stricter on the amount flexibility it will allow before taking action to prevent what it sees as a potentially engine damaging situation. OBD1 started with the 5th generation civic 1992-1995. OBD2 continued with the 6th generation 1996-2000 and the latest version is OBD3 and can be found on the 7th gen. civic 2001-???.
NOW, 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.
B20B, B20Z: The B20 engine is the newcomer in the game and is highly acclaimed by its supporters. It has several key characteristics that give this engine real potential no matter what route you decide to persue. The B20B came on the 1996-1998 CRV and the B20Z came on 1999-2000 CRV. The B20B made 126 hp but the real jewel was the 133lbs of torque that was easily achieved almost anywhere in the RPM band. It is a small displacement engine that has flat torque line!!! Additionally it was a comparatively low compression engine which means that turbocharging to decent levels is possible without the need to spend hundreds on rods or pistons. The B20Z was more or less the same as the B20B but they changed several head characteristics and the compression was bumped up to increase the horsepower to 146.
There are really two choices for dealing the B20 as far as power goes. You could leave it as is and simply swap the head for B16 model. The cylinder head on the B20B model (particularly the tall intake manifold) doesn’t clear the hoodline of the civic, which is ok since the B16 head swap will add Vtec abilities and increased power. OR you could go about what is called a CR-VTEC conversion. This is what I consider to be the ultimate engine build-up for civics’. You can check out www.crvtec.com for details. The first thing you need to know about B-series engine (B18, B16, B20) is that they all have, for the most part, interchangeable engine parts. So the CRVTEC buildup basically consists of taking the best parts of all the engines and making an unprecedented Frankenstein of motor that has a perfect Rod to Stroke ratio of near 1.75 which allows for great naturally aspirated performance (A HUGE redline) or the ability to turbocharge the engine to very large proportions without worrying about engine stability. It is unfortunately rather expensive but this setup will take you anywhere you want to go. The simple B20/B16 swap costs as follows: $1000-$1500 for the B20 short block, +/- $600 for the B16 head, +/- $300 for the B16 ECU + tranny and other small parts. The price for the CR/VTEC could be calculated on the aforementioned site.
Unless you’re simply happy with the stock B20 swap, the only reasons it should be considered are CRVTEC conversions or Forced Induction. The aftermarket support isn’t as plentiful for the B20 as it is for the other engine mentioned so any engine upgrades usually come from other B series or upgraded aftermarket parts for other B series. Which is more less slowly building a CRVTEC engine. But I still highly recommend this engine for the best bang for the buck power adder.
H22A1, H23A1, H22A4: The H23A1 came on the lude Si’s, the highly acclaimed H22A1 came on the 4th gen Si VTEC models and H22A4 came on the 5th generation Si VTEC’s.. And all three engines are MONSTERS compared to what we’re used to. The H22A1 produces a nice 190 hp while the H22A4 produces an even greater 195hp and the H23A1 produces 160hp but they all produce a THICK ASS 160 lb.-ft of torque at relatively low rpm. Giving your 2500lb civic wheel spinning capabilities comparable to a V8 F-body. The whole engine should cost about the same as a GSR swap, $3000-$3500. The down side is the fact that the engine also weighs about 200 lbs. more than the engine you have in your bay now. This effectively makes your weight distribution even worse than what it was before. This causes all types of havoc with your other systems, including suspension, braking and cooling. The engine is also of course very large in size so it’s a tight fit into the tiny civic engine bay providing that you make space by removing both air-conditioning and power steering systems.
From talks with several veteran H22 swappers I can give you the overall driving opinion. To make the swap work, first off the springs and shocks in the front need to be stiffened to appropriately handle the extra weight. The overall suspension tuning should concentrate on trying to create heavy oversteer to offset the natural understeer problem the extra weight will create. There is another way to offset the understeer problem but most ppl don’t want to go through with it. It involves placing a few hundred pounds of weight in the trunk to even out the weight distribution. But most ppl want to go the other way by stripping everything out of the interior, effectively making it worse. The cooling system will amazingly enough be fine for about 75% of the time. However, on hot days or with spirited driving, the engine can start to overheat itself. For the financially strapped, an extra wide Integra radiator can be swapped in for about $100 that will provide all the extra cooling you need. You can learn about it here: http://www.hybrid.honda-perf.org/tech/jsrad/jsrad.html. If you have the extra money, you could swap in an all aluminum thick ass racing radiator with a smaller and more efficient fan and for extra insurance, a low temperature thermostat (160 degree rather than 180) could be replaced. Considering you no longer have air-conditioning the extra space that was once used by the AC condenser could be put to good use and it could be used for an external oil cooler. With this setup you could go uphill mountain racing without fear overheating. The braking system for the most part could work but if you really want to trust your life to stock system, be my guest. If you’d like to upgrade it, the cheap way is to replace the rotors for better heat dissipation (You could either get stock sized cross-drilled or slotted rotors, or you could opt for a bigger rotor kit that uses a relocated bracket so you can use the stock calipers) better brake pads and rear brake disk swap if not already equipped (Instructions HERE). If you have some money, you could get a 4-piston caliper upgrade with extra large rotors with great pads. Just the thing to stop you at 150 mph. If you do opt for the bigger rotor upgrade, remember that the stock wheels will no longer fit over the larger brakes. Some systems suggest 16” or larger.
Let me remind you that this is all extra $$$. The basic swap still includes about $1000 worth of junkyard parts just to make it work, which includes axles, linkages, ECU, HASport mounts, etc. PLUS the cost of the engine itself. This is definitely not the cheap swap.
F20B: This 2.0 liter engine is the rarest of all the swaps. It’s the JDM Accord Si-R engine and it produced a healthy 200hp. The reason I leave this for last is because finding one is like trying to find an unlit cigarette from the 70’s and finding parts for them are even harder. Although not impossible to swap though, it falls under the same category as the H22 swaps. In fact the mounts for swapping the H22 will also work on the F20B. I’ve never personally seen or even heard of this swap done so there has to be a reason for it. I would advise to consider other options.
Ok, So far we’ve covered the D16Z6, D16Y8, D15B7, B16A1, B16A2, B16A3, B16B, B17A, B18B1, B18C1, B18C5, H22A1 H23A1, H22A4 and the F20B. Talk about choices!!! But we’re only half way through. Now we go to the second part of the swapping experience, which is cylinder head swapping. Sometimes called a Frankenstein, engine hybrid, mini-me or LS/VTEC swaps. Head swapping usually includes getting a Non-Vtec block (B18B, D15B) and taking the entire cylinder head assembly from a Vtec enabled block (B18C1, D16Z6) and swapping it onto the Non-Vtec block. Effectively giving the non-Vtec block Vtec capabilities just like his older brothers. Hence the name LS/VTEC. LS for Non-Vtec and Vtec for…Vtec . It isn’t easy though. The Vtec assemblies use oil to activate the system so oil lines will need to be tapped, the block and head need small preparations to flawlessly mate the two and the ECU from the Vtec enabled block will also be needed. So the grocery list includes the ENTIRE cylinder head set and everything attached to it, The intake manifold, throttle body, throttle cable, distributor, Vtec solenoid, EVERYTHING. You will also need the ECU, Vtec oil pump and various other lines and fittings and someone who’s done this before. Here’s a great site that gets to the nitty gritty of the procedure: http://www.geocities.com/thelsvtec/
Now this opens up a whole new world of possibilities. But first you need to know the rules before continuing. These are:
There are of course downsides to mating two engine parts that were not designed to be together and expecting to work together. One of the main problems is that Vtec enabled blocks were designed to rev allot higher than their non-Vtec counterparts. Of the things Honda designed into the Vtec blocks to help them survive high rpm use are oil squirters. Oil squirters serve dual functions both as piston coolers and piston lubricators. Both of which are very important when revving to 9000 rpm. The lack of which could result in damage from prolonged high-rpm usage. Another aspect is that non-Vtec blocks usually have worse R/S ratios making the situation that much worse. The stock oil pump will also need to be replaced as it might not have enough pressure to satisfy both the block lubricating needs and the oil-activated Vtec assemblies. Valve clearance is another issue that needs to be addressed before you not only mate the head and block but also play with cam timing. The valve relief’s in the stock pistons are usually deep enough to accommodate the new longer travel of the Vtec valves but if they aren’t, they need to professionally widened or aftermarket pistons need to be used. And when using camshaft gears to tune cam shaft timing, each setting both 2 and 4 degrees advance and retard need to be tested for valve clearance as well. Failure to do so may cause the valve to crash into the piston when it arrives at TDC (Top Dead Center) which could bend it or chip it which may cause even more damage. Either way the head needs to pulled and repaired.
Head Swapping Pros:
One of the points of swapping in a Vtec head is they usually flow allot better than their non Vtec counter parts. And this can even be improved further with a port and polish. So with that in mind, the best flowing DOHC heads can be rated in this order:
The B16B head is by far the best head but it’s rather expensive and rare. It’s basically a B16A head with a factory P&P and lighter valvetrain assemblies among other things. This goes as well for the Integra Type R head. It’s basically a GSR head with a factory port and polish, slighter better and lighter cams, valves, springs, etc. The best compromise for price and availability is the B16 head and the last one the list would be the GSR head. Of course it needs to be said that simply swapping the head onto your engine won’t give you all the HP from the engine the head came from. Like swapping an GSR head onto an LS block won’t automatically give you 170hp. There were more changes to the engines than just the head like displacement, compression and air flow tracts. But it’s still better than your stock head.
In reality, the majority of your engines power capabilities come from head design. This goes especially for naturally aspirated engines. With each one of these head swaps, you could completely redo all the components in the head to make the HP jump even greater. The exact changes of course depend on if you want to stay naturally aspirated or decide to take the plunge into forced induction. The details of both will be covered on another article. Also between the generations, small changes were made in an effort to produce more power and better mileage. Example, the SOHC head changed from the 5th generation to the 6th gen. In particular the quench area, the area where the compressed air and fuel collect when the piston reaches TDC, was changed to a more squared area. Rather than the circular area on the 5th gens, this new square quench area forces more of the A/F mixture closer to the spark plug which results in a cleaner and more powerful burn. These subtleties can greatly affect the overall power production of your new engine design.
So now, what are your greatest bang for the buck options? Let’s break them down by what engine you have:
D15’s: Say you have a Dx or Cx engine, then you could go ahead and swap out the head for a D16Z6 head. You could probably get the whole swap for $300. The 6th geners with Cx’s or Dx’s can swap for a D16Y8 and build that for greater NA or FI power.
B16: Swapping the head on this engine isn’t really necessary since the head is already a top-notch design. What could be done is a head redesign (P&P, Cams, valves) or you could swap it for a B18C5 head, which is better, but not by much. This swap would be more for the WOW affect. Although a turbocharger or supercharger can both easily be installed on this engine and its air flow characteristics let it achieve more than 200 wheel hp.
B18B’s: The GSR or B16 head swap would be ideal in these situations. Can also be turbocharged by using the kit designed for the head you swap in. But as mentioned before, the R/S ratio would still be a limiting factor in maximum power output.
B20B, B20Z: Now HERE’S where the real deal is. Since the giraffe intake on the B20B doesn’t clear the hood, the head has to be swapped anyways, so you could use any of the choices above as well for the B20Z. My personal favorite, you swap in a B20 with lots of usable torque, then you swap in a modded B16 head and make a few ECU changes, like rev limiter and now you have lots of torque with Vtec high end and an 8000 redline. Or the low compression rate allows for decent turbocharging and you can achieve great heights with the B16 head flow.
H23A1: Generally the swap here is an H23 block with an H22 head swap. It makes for great Vtec high end and the larger displacement block makes for the biggest torque of all the engines listed here.