Dennisrh
True Classic
Part I
I have been working on my K20 Swap for about a year and a half and am near completion. I have been driving the car for about three weeks and am just working out a few kinks here and there. When I saw the first Midwest Bayless K20 swap I was amazed and intrigued in that it was the perfect engine swap in my opinion. I have seen other engine swaps and performance options for the X 1/9, but was never satisfied with the dollar/hp result. Back in the 90s I almost did a Dodge Daytona turbo engine swap, as I had a beat up Dodge Daytona Turbo for a while. Always thought the X 1/9 was the perfect car except for the lack of horsepower. I almost sent my X 1/9 to Matt right after he put the information up about the first K20 swap. My main reservation, was with how much of the frame and firewall had to be cut from the X 1/9. I just couldn't bring myself to cut a perfectly good X 1/9 that much. I started doing research on the K series engines and then a by random chance I ended up with both the money and perfect X 1/9 for a swap. My 1985 X 1/9 got wrecked and I got a decent amount of money from the insurance. Posts about it is here http://xwebforums.com/forum/index.php?threads/24163/
I decided to experiment with a K20 build and felt that I wouldn't feel too bad if I had to cut up my 1985 since it was almost on its way to the junkyard anyways. I also wanted to see if I could modify the K20 engine to fit in an X 1/9 rather than modify the X 1/9 to fit the engine.
So here is what I did:
First got a 2002 RSX type S donor car. The car ran great. Had lots of power and shifted through the gears smoothly. The car had 120,000 miles on it, but I have been told that the K20 engine is good for a lot more than that. I had my mechanic friend do a leak-down test and check for any fault codes on the computer and other than a valve cover gasket oil leak and a broken sensor, the engine and transmission where in great shape.
Took the engine transmission and wiring harness out. All as one unit. I did not detach the wiring harness or transmission during the entire build.
Bought the kit from Matt, installed the subframe, and had it welded.
I removed the subframe from the car and then removed the water pump, alternator, intake and exhaust manifolds from the K20 and bolted the subframe to the engine.
I then began test fitting the engine on the subframe into the X to see where it was absolutely necessary to cut. To my surprise the only place where my engine was hitting and absolutely needed to be cut was the drivers side wheel well, where the transmission housing was hitting. I didn't take a picture of the area, but if i remember to, I will when I remove the engine to paint the engine compartment. Basically the area where the indentation is for the X 1/9 transmission needs to be opened up to allow for the larger transmission. Instead of cutting the whole frame rail like the otehr K20 builds i saw online, I cut a very small section of the rectangular frame rail out and then bent the metal together making the frame rail more triangular than rectangular. I removed about 1.5 inches width x 8 inches length. I removed a little metal at a time and then test fitted over and over again until I had made enough room for the transmission. The clearance is extremely close, but so far after driving the car for about 3 weeks I haven't had any rubbing or knocking of the transmission against the frame. The engine fit pretty nicely within the engine bay of the X 1/9 with absolutely no cuts to the front frame or firewall. Only problem was, I wasn't going to get the water pump alternator or intake manifold back on without doing some modification to the engine bay. First thing I found is that you can delete the water pump on a K20 and put an electric water pump in its place. This not only saves space and weight, it reduces drag on the engine, so more power as well and it relocates and changes the alternator from the large heavy RSX alternator to a smaller alternator from the base civic. The civic alternator is smaller and closer to the engine block than the RSX alternator and it plugs right into the RSX wiring harness, no modification necessary. (its amazing what these Honda guys have all ready figured out for this engine for drag racing)
I had successfully reduced the amount of room I would need for the water pump, alternator and pulleys on the engine. I test fitted the engine and installed the water pump block off plate with the alternator on it and put the belt on the pulleys. The belt hit the corner of the engine bay, so I needed to make an indentation in the frame rail to allow for some clearance. I bent the metal rather than cutting it and was able to make about an inch and a half of clearance just bending it. This was enough to allow for the belt.
The picture is a bit dark, but you can kind of see where the alternator bracket is and the metal on the X 1/9 is bent in the top right hand corner.
Part II
So a list of things I did cut.
The engine mount on the passenger side of the car was cut off.
The bottom bracket for the radiator overflow tank was cut off (I am not sure this was completely necessary, but it did make it easier to get the transmission in)
Various small bolts that were sticking through the firewall.
Things I did not cut that usually are cut in a K20 build:
the firewall
Frame rail below the firewall
left and right side frame rails (except as noted for the transmission)
Rear trunk and exhaust area.
Rear engine mount (the top one for the dog bone mount)
The main issue with the K20 motor needing more room than an X 1/9 can provide is for the K20 intake manifold. The K20 intake manifold is huge compared to the Fiat one. The firewall on the X 1/9 is convex when looking at it from the rear of the car. This convex part of the firewall interferes with the K20 intake manifold. This is, in my opinion the main reason to cut the box out of the firewall. I looked into several different manifolds that were either smaller or curved upward. Several Individual throttle body intakes almost fit. There is also an individual throttle body intake that they use on Lotus Exige swaps that curves upward. Here are some of the measurements I took prior to any bending.
As you can see, I only had between 7 1/2 to 8 1/2 inches between the head and the firewall. Since I couldn't find an intake that would fit in such a small space, I designed one.
I sent this crude design to a fabricator that makes custom intakes for turbo applications. He was more than willing to make this for me, but he said that with the runners being as short as they were, that I would have very little low end torque and my power would probably not really start until 9,000 RPM. This is not the performance I was looking for. At the end of the day, i wasn't going to spend 2 grand on an intake that I wasn't sure would fit or work right, so I made my bends in my firewall to accommodate the stock intake. I bent the rear firewall and ended up with about 9 1/2 inches of clearance, which is just barely enough for the stock manifold.
About 1/2 inch of clearance to be exact. My firewall is now a bit concave where it used to be convex. However, I think that I could still fit a small emergency spare in my spare tire compartment.
Part III
Engine with the intake now fits in the engine bay. Time for some plumbing. With the electric water pump, i could have forgone a thermostat, but I decided it would be a good idea to have one. I used the Lancia thermostat that Matt has used on previous K20 conversions, but I did find that there are many other thermostats that will work just as good. I do not recommend the inline thermostat that K-tuned sells as it is a single action thermostat that completely inhibits water flow. This is bad for an engine as it can create hot spots. a dual action thermostat is the way to go. the plumbing was a bit complicated and I am still tweaking the system to allow maximum water flow. AS you can see in th epicture witht the electric water pump, there is a short rubber hose connecting the water pump to the thermostat. The thermostat is then connected to the hose exiting the head on the open when cold side of the thermostat. The open when hot side of the thermostat is connected to this T-shaped junction.
The black and green hose goes to the expansion tank return line. The other hose connects to the radiator out pipe.
The -AN line in the pic above (black with red/blue fitting) is the return line to the radiator. I found an adapter to go from -16 AN line to smooth rubber hose. I used the K-tuned upper coolant outlet instead of the stock RSX outlet, because it allows you to change the angle of the exit hose and can use -AN lines. This set up works well as the -AN line is much more rigid than regular rubber hose, so I don't have to worry too much about the line collapsing from bending.
Fuel lines where next.
Fuel pump bracket was modified for a lower profile.
Stock fuel pump, stock fuel filter. Used regular rubber hose to go from the fuel filter to the fuel rail.
The other side of the fuel rail has the fuel pressure regulator and the return line connects to the stock Fiat return line (fuel injected Fiats).
This part was pretty easy.
Next came the shift cable linkage. Inside the car, I had to cut the center tunnel to fit the stick shift assemble, but I only cut what was absolutely necessary, so I have overlap between the metal of the stick shift assembly and the center tunnel (about to the second screw from the bottom). I drilled holes in the tunnel and put the bracing bracket inside the tunnel instead of on top of the tunnel. The screws go through the metal of the tunnel and hold the Stick shift assembly secure. No welding was necessary.
On the transmission side I did a bit of frabrication. I cut the Acura RSX cables and drilled and tapped the end links to match the thread on the end of the cables Matt supplied me. I also cut the bracket off the RSX lines and used them to attach the lines to the RSX shift linkage. Top cable is the RSX cable, bottom is the cable supplied with the kit.
Cables modified.
It is also necessary to pull the cables further away from the linkage for them to work properly. I made an aluminum plate to accomplish this.
This is the mock up piece of aluminum. I forgot to take a pic of the final fabricated piece. It looks exactly the same only it is thicker and isn't missing a bolt.
Still more to come.
I have been working on my K20 Swap for about a year and a half and am near completion. I have been driving the car for about three weeks and am just working out a few kinks here and there. When I saw the first Midwest Bayless K20 swap I was amazed and intrigued in that it was the perfect engine swap in my opinion. I have seen other engine swaps and performance options for the X 1/9, but was never satisfied with the dollar/hp result. Back in the 90s I almost did a Dodge Daytona turbo engine swap, as I had a beat up Dodge Daytona Turbo for a while. Always thought the X 1/9 was the perfect car except for the lack of horsepower. I almost sent my X 1/9 to Matt right after he put the information up about the first K20 swap. My main reservation, was with how much of the frame and firewall had to be cut from the X 1/9. I just couldn't bring myself to cut a perfectly good X 1/9 that much. I started doing research on the K series engines and then a by random chance I ended up with both the money and perfect X 1/9 for a swap. My 1985 X 1/9 got wrecked and I got a decent amount of money from the insurance. Posts about it is here http://xwebforums.com/forum/index.php?threads/24163/
I decided to experiment with a K20 build and felt that I wouldn't feel too bad if I had to cut up my 1985 since it was almost on its way to the junkyard anyways. I also wanted to see if I could modify the K20 engine to fit in an X 1/9 rather than modify the X 1/9 to fit the engine.
So here is what I did:
First got a 2002 RSX type S donor car. The car ran great. Had lots of power and shifted through the gears smoothly. The car had 120,000 miles on it, but I have been told that the K20 engine is good for a lot more than that. I had my mechanic friend do a leak-down test and check for any fault codes on the computer and other than a valve cover gasket oil leak and a broken sensor, the engine and transmission where in great shape.
Took the engine transmission and wiring harness out. All as one unit. I did not detach the wiring harness or transmission during the entire build.
Bought the kit from Matt, installed the subframe, and had it welded.
I removed the subframe from the car and then removed the water pump, alternator, intake and exhaust manifolds from the K20 and bolted the subframe to the engine.
I then began test fitting the engine on the subframe into the X to see where it was absolutely necessary to cut. To my surprise the only place where my engine was hitting and absolutely needed to be cut was the drivers side wheel well, where the transmission housing was hitting. I didn't take a picture of the area, but if i remember to, I will when I remove the engine to paint the engine compartment. Basically the area where the indentation is for the X 1/9 transmission needs to be opened up to allow for the larger transmission. Instead of cutting the whole frame rail like the otehr K20 builds i saw online, I cut a very small section of the rectangular frame rail out and then bent the metal together making the frame rail more triangular than rectangular. I removed about 1.5 inches width x 8 inches length. I removed a little metal at a time and then test fitted over and over again until I had made enough room for the transmission. The clearance is extremely close, but so far after driving the car for about 3 weeks I haven't had any rubbing or knocking of the transmission against the frame. The engine fit pretty nicely within the engine bay of the X 1/9 with absolutely no cuts to the front frame or firewall. Only problem was, I wasn't going to get the water pump alternator or intake manifold back on without doing some modification to the engine bay. First thing I found is that you can delete the water pump on a K20 and put an electric water pump in its place. This not only saves space and weight, it reduces drag on the engine, so more power as well and it relocates and changes the alternator from the large heavy RSX alternator to a smaller alternator from the base civic. The civic alternator is smaller and closer to the engine block than the RSX alternator and it plugs right into the RSX wiring harness, no modification necessary. (its amazing what these Honda guys have all ready figured out for this engine for drag racing)
I had successfully reduced the amount of room I would need for the water pump, alternator and pulleys on the engine. I test fitted the engine and installed the water pump block off plate with the alternator on it and put the belt on the pulleys. The belt hit the corner of the engine bay, so I needed to make an indentation in the frame rail to allow for some clearance. I bent the metal rather than cutting it and was able to make about an inch and a half of clearance just bending it. This was enough to allow for the belt.
The picture is a bit dark, but you can kind of see where the alternator bracket is and the metal on the X 1/9 is bent in the top right hand corner.
Part II
So a list of things I did cut.
The engine mount on the passenger side of the car was cut off.
The bottom bracket for the radiator overflow tank was cut off (I am not sure this was completely necessary, but it did make it easier to get the transmission in)
Various small bolts that were sticking through the firewall.
Things I did not cut that usually are cut in a K20 build:
the firewall
Frame rail below the firewall
left and right side frame rails (except as noted for the transmission)
Rear trunk and exhaust area.
Rear engine mount (the top one for the dog bone mount)
The main issue with the K20 motor needing more room than an X 1/9 can provide is for the K20 intake manifold. The K20 intake manifold is huge compared to the Fiat one. The firewall on the X 1/9 is convex when looking at it from the rear of the car. This convex part of the firewall interferes with the K20 intake manifold. This is, in my opinion the main reason to cut the box out of the firewall. I looked into several different manifolds that were either smaller or curved upward. Several Individual throttle body intakes almost fit. There is also an individual throttle body intake that they use on Lotus Exige swaps that curves upward. Here are some of the measurements I took prior to any bending.
As you can see, I only had between 7 1/2 to 8 1/2 inches between the head and the firewall. Since I couldn't find an intake that would fit in such a small space, I designed one.
I sent this crude design to a fabricator that makes custom intakes for turbo applications. He was more than willing to make this for me, but he said that with the runners being as short as they were, that I would have very little low end torque and my power would probably not really start until 9,000 RPM. This is not the performance I was looking for. At the end of the day, i wasn't going to spend 2 grand on an intake that I wasn't sure would fit or work right, so I made my bends in my firewall to accommodate the stock intake. I bent the rear firewall and ended up with about 9 1/2 inches of clearance, which is just barely enough for the stock manifold.
About 1/2 inch of clearance to be exact. My firewall is now a bit concave where it used to be convex. However, I think that I could still fit a small emergency spare in my spare tire compartment.
Part III
Engine with the intake now fits in the engine bay. Time for some plumbing. With the electric water pump, i could have forgone a thermostat, but I decided it would be a good idea to have one. I used the Lancia thermostat that Matt has used on previous K20 conversions, but I did find that there are many other thermostats that will work just as good. I do not recommend the inline thermostat that K-tuned sells as it is a single action thermostat that completely inhibits water flow. This is bad for an engine as it can create hot spots. a dual action thermostat is the way to go. the plumbing was a bit complicated and I am still tweaking the system to allow maximum water flow. AS you can see in th epicture witht the electric water pump, there is a short rubber hose connecting the water pump to the thermostat. The thermostat is then connected to the hose exiting the head on the open when cold side of the thermostat. The open when hot side of the thermostat is connected to this T-shaped junction.
The black and green hose goes to the expansion tank return line. The other hose connects to the radiator out pipe.
The -AN line in the pic above (black with red/blue fitting) is the return line to the radiator. I found an adapter to go from -16 AN line to smooth rubber hose. I used the K-tuned upper coolant outlet instead of the stock RSX outlet, because it allows you to change the angle of the exit hose and can use -AN lines. This set up works well as the -AN line is much more rigid than regular rubber hose, so I don't have to worry too much about the line collapsing from bending.
Fuel lines where next.
Fuel pump bracket was modified for a lower profile.
Stock fuel pump, stock fuel filter. Used regular rubber hose to go from the fuel filter to the fuel rail.
The other side of the fuel rail has the fuel pressure regulator and the return line connects to the stock Fiat return line (fuel injected Fiats).
This part was pretty easy.
Next came the shift cable linkage. Inside the car, I had to cut the center tunnel to fit the stick shift assemble, but I only cut what was absolutely necessary, so I have overlap between the metal of the stick shift assembly and the center tunnel (about to the second screw from the bottom). I drilled holes in the tunnel and put the bracing bracket inside the tunnel instead of on top of the tunnel. The screws go through the metal of the tunnel and hold the Stick shift assembly secure. No welding was necessary.
On the transmission side I did a bit of frabrication. I cut the Acura RSX cables and drilled and tapped the end links to match the thread on the end of the cables Matt supplied me. I also cut the bracket off the RSX lines and used them to attach the lines to the RSX shift linkage. Top cable is the RSX cable, bottom is the cable supplied with the kit.
Cables modified.
It is also necessary to pull the cables further away from the linkage for them to work properly. I made an aluminum plate to accomplish this.
This is the mock up piece of aluminum. I forgot to take a pic of the final fabricated piece. It looks exactly the same only it is thicker and isn't missing a bolt.
Still more to come.
Last edited by a moderator:
