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90 gs engine swap

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  • 90 gs engine swap

    So here is some background first. 6 months ago i picked up a 1990 integra gs. It has the b18a1 engine with 241,xxx on the motor. I am loving the car , with the exception with the power. I have had 3 cars before this one, a a4 1.8t and two gti's. I was going to put a b18c1 head on the block i have now but I have decided against this because i would also be rebuilding the block and tranny. I figure i may as well just do a whole conversion.

    Now this is where i am g=having trouble. I was originally looking to find a b17, but in my area, mass, i could not find one that hadn't been wreaked. So i talked to a couple people and they said get a b16, b18, or a k20. In my mind, I would like to go with a k24 black with a k20 head, but i am not sure if this is a good idea or not. My budget is $5000 for motor, tranny, misc. parts, and labor needed.

    I was hoping to get some direction from people on here since you are all so knowledgeable.


  • #2
    expect to pay nearly 10k for a proper k-series swap into the DA chassis. 5k for the motor and trans is attainable, but not the whole swap.

    to be honest, i would spend the 5k on rebuilding/refreshing and boosting the factory B18

    or you could get a lower mileage B20 for cheap, get an Si, GSR or type-R head and build a mild B20vtec motor (or you could use the B18 block to save some money and have a wild LSvtec motor)


    • #3

      I am about to start rebuilding the B17A1 in my GS-R and I wrestled with the idea of a swap before deciding to spend more and rebuild this engine. The main reason I decided to rebuild is simply because I don't have a place to store the B17 block and I wouldn't want to separate it from the car.

      As far as swaps go, my conclusion was that a B18C (GS-R style) would be the best bang for the buck. People say that the B16 is a blast, but I can tell you that even the B17 is kind of lame after driving my LSS with GS-R transmission. Torque is your friend!

      A B18 long block is $1700 from H-motors. As far as I know, they still provide the best engines you can get online. All sensors guaranteed is a big plus to me.

      Cam Seals, Distributor O-Ring, Injector O-rings and gaskets, timing belt, water pump, timing belt tensioner, head cover gasket set, PCV valve, PCV hoses (they will crack and break when you try to take out the PCV valve) heater hoses, fuel filter, etc. (all the stuff you want to go ahead and change because they are 15 year old parts and some of which are easier to put in when the engine is out of the the little fucking heater hoses!)
      will run like $400-600 depending on how proactive you are.

      An appropriate shot geared transmission will be like $500 or so used.

      I would go ahead and re-pin your current wire harness and go ahead and move to OBD-1 with the swap.

      Add another $150 or so for a OBD-1 94-95 GSR ECU or you could just get a chipped ECU with a GSR program on it.

      So if you do all the labor yourself, you are only at about $3k. B16 style Intake manifold is a popular mod to those B18s. ~$250

      So if you get a nice set of headers, a decent intake and exhaust, a CTR intake cam or some other kind of cams, some decent cam gears, maybe upgrade the valvetrain if necessary for the cams you choose and a good tune, decent street clutch, nice ITR or street flywheel and that will probably burn through the rest of that $2k pretty quickly. I'm not sure if that $5k is all of your budget, but the car won't be too fun if you just have the old tired worn suspension on it. Poly bushings are a minimum upgrade as far as I'm concerned.

      Or, you could keep the LS transmission, get that longblock, not do any maintenance on it, get a used turbo setup, boost it lightly and pray it all holds together.


      • #4
        thanks weasel and buymysoul for the quick replies!

        Basically, this would be an ongoing project for me. I have about 2k in the bank, and i was hoping that i would be able to do it all for under 5k. If i have to go over that, its fine as long as it will make it an even more bitchin' setup. I am just having trouble deciding what would give me the best bang for my buck. Build my motor with a vtec head, buy a b18c, or go some other rout. I figure eventually i will get used to the power and want to go turbo also.
        If i did get a new engine (and that one you recommended looks like the one) I would still be able to drive my car whilst i am building that engine. However, what should I do about getting a tranny? i was looking at jdmenginedepot and they come with transmissions also. are they any good?
        Also, this would be my most involved project by far. If I did encounter any trouble, how much would a garage charge to do this project for me?


        • #5
          I won't even guess at how much a garage would charge. I had a normal joe blow shop put a (dual carb) B20 (old school B20 from a 88 era prelude) in my prelude many years ago. They couldn't get it to run and I had to take it to another shop. Ended up costing me like maybe $4k when it was all said and done and they didn't even do any of the maintenance stuff I mention above. I got completely screwed, but I was young and learned my lesson.

          After that car, I started figuring out how to do the work myself. I don't find systems in general very difficult to understand, so I look at something and see: well to take that off, I have to take that off and then that...

          The key is to not be in a rush. If you have to wait until a place opens on Monday to get the right part, just wait, don't try to fudge something together. Same thing with having the right tools.

          (sometimes 8mm), 10mm, 12mm, 14mm, 17mm, 19mm 6 point 3/8" sockets in both short and long, a variety of extension bars, a decent ratchet (I like my long handle craftsman pro), a 1/2" breaker bar and 1/2" impact socket, nice combo wrenches in all the sizes above and then some kind of wratcheting wrench in all the sizes (so you have two of each size when necessary) and the Honda crank shaft pulley holding tool from Napa and you can pretty much take apart a honda from the front to rear bumper. There are a few insanely big wrenches for some random stuff (oh, wait, you'll need a 6 point (1 1/4") 1/2" drive for the axel nut. I've found the 1 1/4" craftsman actually fits better than the so much more expensive 32mm. A decent torque wrench, a HELMS manual, a little tiny sledge hammer (I call mine Thor) and some kind of combo rubber/plastic mallet, a decent pry bar and man, you will be all set. Some decent thin mechanics gloves, some latex gloves are also handy. Obviously you'll need an engine hoist or a strong tree branch too, but that is a given. I also have a tool that is specifically made for getting enough torque on the crankshaft pulley bolt. Black plumbers pipe: I cut a slit in the end and had a friend weld in a 1/2" impact extension bar, about 2' long with a T screwed on and then welded into the end. A 6' pipe screws into the T. Support it on a jackstand it it'll get ANY crankshaft pulley off.

          But if I had the engine out of the car, I would just take it to a shop with a good impact gun and get them to remove it.

          Anyway, not to get derailed, but you will find an engine swap with an engine that is just refreshed a lot easier (and safer) and probably cheaper than an LS/VTEC setup.

          The transmission on B18C engines have hydro activated clutches (yours is just mechanical). There is a conversion kit out there, but my feeling is that it adds extra complexity that isn't needed. Plus, if memory serves, they don't have a mount so you loose that extra stability point. You could get it and then sell it and then get a 'cable' transmission, but I hate selling stuff online and would just skip that step.

          As far as having the car drivable, that is true but you would still have some down time while getting the wiring all sorted out. But you could save some of that by buying a used harness online. The JDM harnesses come out on the driver's side I believe and are harder to make work.

          Sorry I tend to ramble. Hopefully this is helpful.



          • #6
            Dont worry about rambling. Its good to have the info.
            I am only 18 so i dont have all that much experience. All I have done is install new struts, springs, done some body work, attempted a rear disk replacement and failed because i could not compress the calipers enough to get them over the new pads, install a fmic. none of this has been on a honda, just a audi.
            i would need to get a stand for the engine so i can work on it. how would I go about lifting the engine out of the bay and back in. Would I need to get a engine lift?
            Also, I am kind of confused as to what you are saying about the transmission. The one in my car grinds a bit in third forth and reverse. also the syncro for third and fourth seems to be shot.
            As for the wiring harness, I hadnt even considered that. if i got that engine from h motors, would i also want to buy the p78 thats $200? would I be able to make my own harness? i have some experience with wiring. would I be able to use the connectors that are all in my car at the moment?

            Sorry for all of the questions. I am a noob when it comes to this sort of intense car stuff.

            I appreciate everyone's help,


            • #7

              First off, I'm going to give you the obligatory emoticon. Don't take it personally. All this info is out there, but I also understand it is frustrating to find it because it is mixed in with so much other bullshit. Years ago, we all found out this information by just asking about it and then later got jaded by having to repeat it over and over (thus the creation of the search emoticon).

              You will need an engine stand. I believe that a lot of autoparts stores allow you to rent or borrow lifts but I have never had to do this. Although I'm far away from my friends with that stuff now, so when I pull my B17 in the next few weeks, I'll let you know what I find.

              You will need a nice big C clamp to compress the calipers in your Integra. Although frequently they will push in by hand. I suspect your Audi had the kind where there is a big + on the inside of the piston and you are actually supposed to twist (screw) it in to compress it down. I had a caliper like that vex me once.

              What I mean by the transmission is that a hydro transmission comes with the engine you are looking at. Our cars use a cable transmission (cable actuates the clutch instead of a hydraulic line). I'm not saying you should use the one you currently have, but that you should buy a used cable transmission. There are two kinds, the one you have is referred to as a "long geared" transmission, but the ones that came on the 92-93 GS-R in the states and the one that came on B16 engines in Japan (and elsewhere) are "short geared". You can look that stuff up, but a short geared is more appropriate for a B18C engine.

              Doing an engine swap isn't hard. I did them when I wasn't much older than you. In my opinion they are much less difficult than rebuilding an engine. You just need to take your time and occasionally you will need someone to help you with stuff.

              I would skip the GSR ECU and just get a chipped ECU from Xenocron. Just tell him that you have an OBD-1 B18C GSR engine and he will put the appropriate "basemap" on a chip for you. Later, if you decide to upgrade cams and all that good stuff, your tuner (at a Dyno) will be able to easily tap into that ECU to make you a new map for whatever mods you get.

              The wiring plugs are different in your current car (OBD0) than in the GSR engine you would get (OBD1). But what you will do is take your existing harness and ONE PLUG AT A TIME switch it to the plugs that you will cut off of the engine harness that comes with the new engine. There are guides out there (FYI, I didn't bother reading that one) but the last time I followed a guide like that it was a fucking disaster. It had me using the engine harness off of the new engine then swapping around all sorts of stuff in the engine bay and on the ECU and it was a mess. After it was all said and done, we broke out the wiring diagrams and realized if we had used the original harness in the car, we would have only had to change like 3 wires (this was a D16A1 1st gen integra engine into a 1st gen CRX SI) BTW.

              Ok, now normally I wouldn't condone this, and it is completely against the rules here, but if you do a google search for factory helms manuals and also put the word "spooner" in the search, you may stumble on a resource that will help you with the swap. The only reason I am pointing this out is because to do the wiring the best way, you will need the wiring diagrams from a honda factory service manual (Helms) and the current reprints from don't include the wiring diagrams you need. You really should buy a real hard copy shop manual though. They are cheap ($46) and -- take it from me -- much easier to use when actually working on a car than a computer or printed sheets.

              It isn't that difficult. So when all the plugs are replaced on the engine, your car will be wired up exactly like it was before except you will have removed your injector resistor box (OBD1 injectors are a different type then your 90-91 OBD0 injectors) and maybe added a few wires (for VTEC and other stuff?) but all the plugs will correspond to the OBD0 pins on the ECU side. But, some of those pins aren't in the right place for OBD1 and also the connectors on an OBD1 ecu are different than OBD0. At this point buy a OBD0 to OBD1 ecu conversion harness to make the changes on the ECU side. They cost like $100-$150. There are countless ways to convert to OBD1, but this makes the most sense to me. If I were you, I would search for OBD0 to OBD1 conversion and see what other people are doing/have done...

              It sounds way more complicated than it is, but give yourself several days to do troubleshooting on the wiring after you are done. You will probably mis-wire at least one connector and will be going through every pin on the ecu and checking the continuity to the plug in the engine bay and banging your head against the wall. This is normal.

              I think I answered all of your questions. Although I have some first hand experience with this kind of stuff, it has been a while since I've done any involved swaps like this with an OBD change, so I am sure I missed out some stuff and probably said a few things that are inaccurate. A good rule of thumb is don't trust anybody on the internet unless they are also willing to come over and help you if you fuck up because of something they said. (and no, I won't be coming over to help).

              To answer your second question explicitly: for the most part, you won't be able to use the connectors on your factory harness. Some stuff swaps over, but most doesn't if I remember correctly.
              Last edited by buymysoul; 14 Jun 2010, 18:45:11. Reason: Meant to say "less difficult" where it used to say "more difficult".


              • #8
                Thanks for the help. I completely understamd and do not take that personally. I have used that .gif many times when I was into audi's.
                I will make sure to pick up a manual. I have been meaning to purely for all the torque specs. I am planning on building the engine that I purchase no matter what I do.
                I have a friend that works at honda and did another friends swap for a few cases of beer. I am sure he would be happy to help if I did the same. I am going to make sure and do some more research before I jump into this project. But hopefully within a month, I will have a new motor in hand.

                I really appreciate your help with answering my questions. I feel a lot more confident about attempting this project now. Good luck with your build, I will make sure to follow it as you go along.



                • #9

                  Thanks. You seem like a reasonable and intelligent guy, I am sure you will do fine. Just don't skip out on the little maintenance stuff along the way. It certainly adds up quick.

                  I am not sure what you mean by "build" but you might want to take a look at my updated parts list (with prices) in my build thread.

                  If I were you, I wouldn't try to undertake the swap and the build at the same. I would change the timing belt, water pump,tensioner pulley and spring, and just drop it in. If you are going to completely rebuild/build the engine that you buy, there is no reason to get one from Hmotors. You could get some cheap tired engine from ebay and save some money since you will be rebuilding it anyway.

                  Good luck!


                  • #10
                    When i say build, I basically mean new pistons, rods, cams, springs, adjustable cam gears, springs, flat faced valves. Nothing too aggressive. Would you think that is worth it? Or should i just get a cheap motor for that stuff


                    • #11
                      Well yeah, I think it's worth it. I'd be a hypocrite if I didn't!

                      You did see that my build to get the car on the road with a full rebuild is going to be like $4k right? And that is only with a $600 head, not a $1700 engine...and I'm not even touching my transmission for now.

                      I'm just saying that Hmotors is supposed to deliver really good condition engines (I've never personally dealt with them) with good compression and good sensors whereas with other folks you don't necessarily know what you are getting.

                      If it was me, and I was planning on doing a complete rebuild, I'd probably check craigslist and find someone who is selling an engine in running condition and rebuild that.

                      There is not a definite answer I can give you. I will tell you this though, when I had an LS, the first thing I worked on was the suspension (after all the maintenance was done). The very, very last thing I would have done to that car would be to swap the engine out for something else.


                      • #12
                        it would be eazier and cheaper to do a b20vtec set up.. just add high compression pistions and a mild p/p on the head and you would have a b20v type r, just make sure you add the basic bolt ons later like intake manifold, header, throttle body and exhaust.. best thing is you can keep it obd0 with a jdm b16 obd0 distributore and chipped ecu.. and keep your cable tranny set up... shop around for a b16 lsd cable tranny, they do pop up every now and then.. nwp4life has a dude selling a jdm b16 Y1 lsd tranny for $600 obo, im sure he might take $400 cash..thats the same tranny i have on my jdm 98 spec type r set up in my DA.. I have it running on a obd0 pw0 chipped ecu and obd0 b16 §§§§§..

                        one thing for sure is invest on some good 200hp axles asap.. i went through 3 sets in 1 month..


                        • #13
                          While the individual parts may come out to around the same cost, there is a shit-ton more incidental stuff to be considered when doing B20 VTEC. The original poster has already expressed concern about his mechanical abilities. There is absolutely no part of sourcing a block from over here, a head from over there, getting a $750 "mild p/p" not to mention having to then machine those parts for the oil delivery to work right and put it all together that is "eazier" than taking a B18C, slapping on a new timing belt/water pump/tensioner doing a little wiring and being good to go.


                          Last edited by buymysoul; 21 Jun 2010, 12:39:47.


                          • #14
                            I think I am just going to go with a b18. if I were to go with the extra .2 liters of displacement, I would preferably go with a k20 setup. Thanks for the heads up on the axles though.

                            I think what I have decided to do is to get my car all squared away first. Basically fix everything but engine. I have some body work to do, dents, a small rust spot, shave some things, and maybe re-spray it. I am definitely open to opinions on what color to paint it. anything but black because I don't want it to match the moldings. Any suggestions? I am also going to look into beefing up the suspension. I will look into some nice sway bars and maybe some coil-overs. The only problem I have is that I have a steep driveway and I can barely make it up without bottoming out so I need to find some setup that wont drop me too much.



                            • #15

                              That is a FANTASTIC plan. Sometimes it is easy to get caught up in all the go fast stuff. I know I have and am guilty of it.

                              Since your transmission is having some issues and you are considering some kind of VTEC B-series engine in the future, you may want to explore upgrading the transmission to a VTEC short geared transmission. It will definitely make the car feel more peppy. Just keep your eye out for one is all I'm saying.

                              What color is your Integra now?

                              I used to think Frost White was the only color that looked good; then I started to really dig the greens. The forest green color of the non-white 93 LSS was a favorite for a while. The Jasper green is also very sexy, but I also like the Aztec Green Pearl of the GS-R, but that is mainly because I find it to be horribly offensively 90s. I am usually a fan of just keeping a car the stock color. Here is a thread specifically dedicated to Jasper Green tegs. Hardly any of the pics show up for me, but I am at work, so they are probably blocking some of them...

                              If you want to go totally crazy but stay in the Honda family, I would check out Barbados yellow which was used on 3rd gen Preludes and 2nd gen CRXs. I had a 88 Prelude SI in yellow and loved that thing! Same color as this one. Oh man, check this one out too. You can't tell me that isn't a sexy color! You would absolutely, positively have to keep the molding black though. I've seen cars of this (our) vintage where all of the trim was painted yellow too and generally it looks pretty stupid.

                              With the suspension, my suggestion is to do the bushings first. You will become very familiar with every piece of your suspension and maybe even be able to identify any problem areas. After you do that, every other suspension modification you make will have more of an impact and work better.

                              My LSS had a front upper tie bar (a good neuspeed one), poly bushings all around and a Progress sway bar and everything else was stock. It was a blast to drive! The ride quality was great but it handled and responded much better than a stock integra. I autocrossed it on that setup and even as a novice did very well as compared to a guy with a DA with I/H/E, progress bar, coilovers, upgraded cams (but no bushings) who had been racing for a couple seasons.

                              I have been trying to figure out what coilovers I'm going to get as well. I am going to be going somewhere between .75"-1.5" lower than stock just because I don't really like that slammed look. I also don't want something that is crazy stiff (just because I'm a pussy, mainly). I have been seriously looking at coilover systems that do not have adjustable damping. My feeling (opinion) is that if a coilover is really made properly for my car -- considering the weight of a stock vehicle and knowing what the spring rates are -- there shouldn't be a need to adjust the shocks.

                              I have also been checking out this article: I feel that the weight of our Integras is close enough that this can be a useful guide. Based on those two things (non adjustable shock, ride frequency) I'm leaning heavily towards the first Progress Coilover on this page. They also make one in the $600 range that does not have rebuildable shocks.

                              Obviously there is a direct trade off between comfort and handling, but when it comes down to it, I put a lot of value in comfort. My significant other isn't going to want to go on weekend drives through the country in this thing if it causes ass bruising!

                              My final setup on my GS-R will be:
                              ES Poly bushings
                              New OEM trailing arm bushings
                              ASR rear subframe brace
                              The Progress sway bar I already have
                              Neuspeed front tie bar (after I remove my ABS)
                              Mildly sprung coilovers with ~1.25" drop
                              Camber adjustment arms if needed
                              15" wheels

                              If you are looking for a mild drop, you should also consider some Koni Yellow dampers and H&R OE springs. If you choose to go with some Ground Control Sleeve type Coilovers in the future (what a lot of guys here run and recommend), these shocks would be a great compliment to them.