K20 project off to a good start

Roger, Thanks I will be starting a thread and posting my progress. I thought that maybe you ran into a specific problem with tying in the rear cross member and routing the exhaust. This site is a rabbit hole for a new guy like me. Loads of information. Great stuff. Many talented people. I have chatted with and visited MWB (only 2hrs away) Matt and Brayden have been very helpful.
 
Roger, Thanks I will be starting a thread and posting my progress. I thought that maybe you ran into a specific problem with tying in the rear cross member and routing the exhaust. This site is a rabbit hole for a new guy like me. Loads of information. Great stuff. Many talented people. I have chatted with and visited MWB (only 2hrs away) Matt and Brayden have been very helpful.
The reason why I said there would be a problem with the cross brace piece that Darin welded in place was because I built my header starting with an eBay cheapy shorty header. The stock Acura exhaust is routed to the left side of the car, so the header outlet is aimed in that direction. When you bring that header outlet into the X exhaust bay, it pretty much goes through the center of the large opening, which is why the MWB directions say to cut out the stock panel as it is in the way. Darin's brace would also be in the way for my header, but he is building a custom header from the flange back so he can easily route his exhaust through the right side opening.
 
Thanks Roger something I will pay attention to. Just trying to avoid any pitfalls that may come with a custom job when so many others have gone before. MWB directions??? In printed form? LOL I will have to check on that for I did not receive a copy. Just the FAQ sheets.
 
Thanks Roger something I will pay attention to. Just trying to avoid any pitfalls that may come with a custom job when so many others have gone before. MWB directions??? In printed form? LOL I will have to check on that for I did not receive a copy. Just the FAQ sheets.
With my kit, I got a 25 page K20-Notes document with lots of photos as well as the FAQ document. I can send it to you by email, but I would think that Matt would provide it if you bought the kit from him.
 
With my kit, I got a 25 page K20-Notes document with lots of photos as well as the FAQ document. I can send it to you by email, but I would think that Matt would provide it if you bought the kit from him.
Matt sent it to me in electronic format (MS Word) - if you paid for the kit already I'm sure he'll just email it to you.
 
This should certainly add to the rigidity of that area, but I can guarantee you would have an issue with the header coming through that opening and your welded in piece being in the way. That is if you were using the shorty headers that are available like I did. I am pretty sure you were going to build a custom header, so that should allow you to bring it back through the right side opening with no issues.

This quoted part is from an older post (here)...

I saw that Hussein (@lookforjoe) liked my post. I'm with Rodger on this tho in so far as limiting the area for the exhaust outlet, so I'm modifying it. Also - and probably more important - I was thinking about how one would install a header (even a "shorty") onto the head with no access available. Thus I've decided to replace that reinforcement with a removable part that is similar. Best of both worlds: keep the rigidity but allow the header to be extracted thru the "muffler bay(?)".

I'll post more in a week when that project is complete.
 
Wiring harness progress

I have been working on creating a custom wiring harness for the car as well for connecting the engine sensors and ECU to the instrument panel and to provide power for the ECU per Hondata’s KPro instructions. A few years ago, I had bought a used wiring harness on ebay, mainly because it had a bunch of relays with it and it was cheap because it was not quite complete. It turns out that it was from a late model Bertone with the newer style fuse panel with the blade fuses. This panel was introduced on the 1985 models. At the time, I did not even know that Bertone had upgraded the fuse panel on the X as my only experience at the time was with my ’79 with the ceramic bullet type fuses. The harness had been harvested in a hurry, so several of the end connectors were missing or cut off and quite a few wires had the insulation shredded off where someone had yanked them through a pass hole without much care. Also, the whole rear harness had been chopped in half at about the seatbelt mounting, but at least both halves were there. My original plan was to upgrade my fuse panel on the ’79, but that turned out to not be very realistic unless I was going to change out the whole harness. I put it away and mostly forgot about it until I embarked on the K20 project. Since I would be adding the wiring for the K20, plus the aftermarket AC system, and all the various relay mods advocated on the Forum, it seemed like it would be a fun project to use that fuse panel and wiring harness for my ’81 restomod, but customized for my specific installation. I would take any missing wires or connectors from the original ’81 harness.

I started working on the harness, but since I was going to modify it quite a bit, I figured I should document my changes, not only for my feeble memory, but also for any future owners. Of course, that is assuming that I will finish the car someday and my wife does not bury me in it. I got a set of the Bertone wiring diagrams and started to figure out what goes where. Of course, the first thing you find out when you look at the wiring diagrams and compare them to the fuse panel is that none of the lettering for the various harness connectors on the wiring diagram match the letters molded into the bottom of the fuse panel. Also, in the wiring diagrams, all the fuses are numbered, but on the panel diagram, the fuses are lettered with no apparent relationship. Bizarre, but this is a Fiat so par for the course. So, I made labels with the letters from the wiring diagram and put them next to the correct opening on the bottom of the fuse panel and labeled the actual connectors to match.


In the wiring diagrams, all the various subsystems are on separate pages. They show the connectors, wire color, and the pin numbers that are used for that subsystem, but you have to flip back and forth through several pages to try and figure out what all the pins in a particular connector are used for since some connectors are used for multiple subsystems. The fuse panel is quite the piece of engineering as it is not just a fuse panel. It also functions as a junction box to route signals or current from a harness from one part of the car to another. For instance, all the wiring to the front of the car is contained in a harness with three connectors A, B, and M. There is a separate harness going to the instrument panel and all the dash switches and controls through connectors F, D, and H. Eight of the relays are plugged right into the top of the fuse panel so there are a lot of internal connections inside that fuse panel that go every which way.

It was hard to keep it all straight, so I took time out and created a spreadsheet for myself that lists all of the connectors, the pin numbers, wire colors, and what they connect to externally and internally. The internal connections can be to a fuse, a relay, or another pin or pins on a different connector. I made two sheets, one that shows all the connections of the wiring harness and a separate sheet that shows all the connections to all the relays, both the ones on the fuse panel and those on a separate cluster of six. I even found a couple of internal routings that are not used in the wiring harness but I have documented them. Now that I have the complete listing of connections as it come from Bertone, I can create a separate spreadsheet with all my changes for future reference. If anyone would like a copy of the factory connection spreadsheet I created, I am happy to share it. Email me, rlawtondmd*comcast.net, and I will send it to you.

Once I had that done, I worked on the front harness. I incorporated Bob Brown’s headlight relay kit into it, but modified it as I got rid of the original headlight connectors. I also added separate right and left fused supply wires. Bob’s relay kit is first class construction.



I also added the circuit for some fog lamps and utilized the wires from the stock AC system and connected that to my aftermarket trinary safety switch mounted on the AC dryer in the frunk. These wires are part of the M connector. They are routed through the fuse panel to other connectors that I will modify to connect to my AC system.



It was good to get the front wiring harness done and installed. I finished adding the front radiator hoses so that part of the car is done!



I completed the harness to connect the K20 ECU and C101 engine connector to the car. It has five pigtails plus three relay sockets. One pigtail goes to the O2 sensor. I used some Fiat connectors to provide plug ins to the wiring harness for the backup lights, the fuel pump, and for switched and constant 12V plus the start signal. I bought an 8 pin Molex plug to provide all of the signals from the ECU and engine to the dashboard gauges.


Here it is plugged into the ECU in the trunk.


I’m almost done with the rear lighting wiring harness, then will work on the wiring for the gauges and AC system.

Just in case you're monitoring posts here - I sent you an email request for the spreadsheet :D
 
FWIW, I just finished replacing of all of the old Photobucket photo links in this thread with embedded photos. I had arthroscopy on my knee this morning, so had all day to sit on my butt with my leg up with time on my hands. There are still a few photos missing, but those are in posts from other members.
 
FWIW, I just finished replacing of all of the old Photobucket photo links in this thread with embedded photos. I had arthroscopy on my knee this morning, so had all day to sit on my butt with my leg up with time on my hands. There are still a few photos missing, but those are in posts from other members.

Now you just need to index each page in the first post, to make it easier to find specifics :- I went back & did that with my two K24 threads when I was stuck after heel surgery :D
 
Now you just need to index each page in the first post, to make it easier to find specifics :- I went back & did that with my two K24 threads when I was stuck after heel surgery :D
I’m not sure exactly what you mean by indexing. Can you explain what to do?
 
Hi there from down under ! Proceeding with K20 swap however i plan to remove the stock K20 water pump and replace it with an EWP mounted elsewhere. Also plan to manufacture a new stubby inlet manifold - both these to possibly eliminate the firewall cut and box. However does anyone know about the clearance required around the starter motor ? Does it protrude into the area here ?
1651960877625.png


If so I assume I would only modify that section.. ??? Thanks in advance ,Doug
 
Hi there from down under ! Proceeding with K20 swap however i plan to remove the stock K20 water pump and replace it with an EWP mounted elsewhere. Also plan to manufacture a new stubby inlet manifold - both these to possibly eliminate the firewall cut and box. However does anyone know about the clearance required around the starter motor ? Does it protrude into the area here ?
View attachment 61498

If so I assume I would only modify that section.. ??? Thanks in advance ,Doug
You might consider making your own thread to gain the answer to this. Giving a good thread label would help you gain the attention of those who know like Hussien and others who have built there cars. There is also a group over on Facebook just for them K swap (not saying you should go there but it is another resource).

It is much more likely to get attention as its own thread as many people won’t delve into Rodger’s thread unless he is the one posting. It is an opportunity for you to have your own thread and share your good work.

Looking forward to seeing more from you.
 
Hi there from down under ! Proceeding with K20 swap however i plan to remove the stock K20 water pump and replace it with an EWP mounted elsewhere. Also plan to manufacture a new stubby inlet manifold - both these to possibly eliminate the firewall cut and box. However does anyone know about the clearance required around the starter motor ? Does it protrude into the area here ?
View attachment 61498

If so I assume I would only modify that section.. ??? Thanks in advance ,Doug
The starter motor is tucked close to the engine block under the intake manifold. It will not interfere with the cross member. Good luck with your build and as Karl (@kmead) suggested, it would be best to start your own build thread. Looking forward to seeing how you avoid the firewall cuts.
 
Hi there from down under ! Proceeding with K20 swap however i plan to remove the stock K20 water pump and replace it with an EWP mounted elsewhere. Also plan to manufacture a new stubby inlet manifold - both these to possibly eliminate the firewall cut and box. However does anyone know about the clearance required around the starter motor ? Does it protrude into the area here ?
View attachment 61498

If so I assume I would only modify that section.. ??? Thanks in advance ,Doug

Just be aware that intake manifold clearance is not the only reason for the big access panel on a K20 conversion. Virtually everything that will ever require service on a K series engine is on the front side of the engine under the intake manifold. That includes WP (OK, you're talking about going electric and moving that, but bear with me,) alternator, starter, coolant hoses, and electrical. And not considering only service, the build/installation process is made much easier by having a panel there to work through--and I don't mean the goofy little distributor panel that FIAT put there.

My next K swap is going to have a bigger panel, not smaller/eliminated.

Also, the Honda engineers really built an excellent intake manifold in the PRB. Meddling with its design (or building an all new one) could lose power unless it is very well designed.
 
Also, the Honda engineers really built an excellent intake manifold in the PRB. Meddling with its design (or building an all new one) could lose power unless it is very well designed.

I guess I should add that, with 200 stock factory horsepower to start, the K20A2 has some power to give up if packaging the swap without cutting the firewall and thus needing to come up with a shorty intake is a priority for you. I'm greedy with power. I don't want to give up any of it, and will cut sheet metal to keep/gain it. If you were to lose 20-30HP on an intake manifold, your K20 X would still be a hoot.
 
I guess I should add that, with 200 stock factory horsepower to start, the K20A2 has some power to give up if packaging the swap without cutting the firewall and thus needing to come up with a shorty intake is a priority for you. I'm greedy with power. I don't want to give up any of it, and will cut sheet metal to keep/gain it. If you were to lose 20-30HP on an intake manifold, your K20 X would still be a hoot.
I suspect the biggest area he is avoiding cutting is the structural tub around the front of the engine or at least minimize it. The firewall is primarily along for the ride so cutting into that I don’t think bothers many aside from losing the spare. Personally I would go after the downdraft manifold approach to minimize manifold issue.

Having a K24 in several of my cars I agree about the need for access and space on the front of the motor given the difficulty of accessing the alternator. Not having to fiddle with the AC compressor to change the alternator will make it much easier.
 
All good stuff - however the long intake runners and plastic plenum underneath are only there for one thing - low speed torque and enhanced efficiency - all good in a heavy car striving for fuel efficiency. Looking at short quad throttle bodies = more power at top end.
Regarding access all that will remain on the block front side is the starter motor , a new one here will last me out!
 
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