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Frankenstein's Monster K20/24 RSX-S

3095 Views 68 Replies 9 Participants Last post by  NecroFIesh
Sup guys, I'm in the middle of my 2nd swap right now...this one is a K20/24 Frank into an RSX chassis. Figured I'd start a thread detailing the build before it's too late. I'm just about ready to mount the motor to the chassis at this point...this is gonna be pic heavy so get your popcorn....

I bought an '02 RSX-S earlier this year. The seller brought it to the dealership with the motor locked up. She was a middle aged woman who had bought it for her son a few years back. Apparently, the son wasn't aware that driving the piss out of the car and not keeping up with oil changes tends to cause problems. I negotiated the blue book value of the car minus the cost of a new engine and took delivery early last May...

I got the oil pan off and soon realized the issue - rod bearing seized in cylinder 3. I removed all bearings, inspected the crank and looked for any other damage. Surprisingly, the crank was barely touched and the oil in the pan had zero metallic flake. The screen in the spool valve filter was also clear of anything so I thought I must've gotten lucky. I know I should've replaced the crank but considering replacement bearings were readily available and OEM cranks are stupid expensive, I opted for the former and replaced bearings only. The motor turned over super smooth by hand and once everything was bolted back up, the car fired right up. It got to temperature and idled fine, no codes present but had audible rod knock at about 2300 rpm in the same cylinder as the seized bearing. I was surprised the sensor didn't pick this up but figured at this point, let's do a swap and so now here we are...

Here's the car - 2002 Type-S in Nighthawk Black pearl with full OEM A-spec kit.....

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Here's the motor - 2005 JDM K24a 3 lobe from

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Shout out to Steve at HMotorsonline for the clean K24a. I highly recommend sourcing your engine from a trusted and reliable provider that's been in the game for over 20 years like these guys. The only catch was the wait time to receive the motor as it was just over a month for it to ship and arrive to me here in VA from Cali. The motor is super clean and came overpacked and strapped to a pallet as seen above. It's also in amazing condition as you'll see in the photos to follow...stay tuned.

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Wow, great find! That rsx and engine look super clean! I have an 03 in nhbp also with the same engine on a stand. Really looking forward to this build thread! Are you pulling engine from the top or dropping it below?

I won't be swapping until my current clutch gives out. Again, nice score!
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A promised, here are some pics of the trimmed Type-S oil pump and refreshed cylinder head mounted to the K24 block, as well as the timing components bolted up...
What kind of work was done on the head? I know the exhaust valve guides are prone to cracking with age/milage/over reving. That head looks in pretty good shape tho. Curious what all was done with it.

Really enjoying the quality pics! Keep em coming for sure!

Happy New Year!
I'm planning on using all of the accessories from my K20 as well as the water passage to utilize the oil cooler upgrade
I think I remember seeing a video that you might have to bend that coolant bypass pipe outward near the thermostat in order for it to make a good seal. Lmk if this is truly the case.

Curious who u went through for the IM and valve cover? Can't say how much I'm loving this build btw
Very smart putting the engine on the subframe first! Coming together quickly
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I need to keep exhaust diameter to 2.5". Please don't tell me how much more power I'll make with a 3" because I already know
What kind of exhaust are you thinking? I will be running into the same issue. 40 mi round trip. I was planning on the q300. Its 2.75" i believe. Hopefully drone isn't too bad.
So it's a full carbon fiber piece
Super sharp my guy. I had no idea hondata even offered these. Where will the ecu go to show this sucker off?
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And a plus rep for anyone who knows what this is..
We used to call those fender guards (fender covers). What a score!

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Mine are not nearly as impressive. Got mine from a friend whose first gig was an audio installer
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Bro, this is how it's done. Doing it right the first time. I'm planning on similar parts for my build. Still not sure when that's going to happen. The current k20a2 seems happy with 240k on the clock.

I realize that a 3" intake setup would be most ideal for power in this build
I'm pretty sure the injen is 3"? Did you mean 3.5"? That would be a tight fit with the stock battery location and tight bends anyway. I was gonna try and build a 3.5 and turn the battery 90 deg to make room. We'll see how ambitious i want to be when the time comes.

That's the K-Tuned center feed fuel line tucked kit with a center mount gauge. A gorgeous piece that's designed for a very clean install, of which I'm stoked to have for this build.
All of these black accent pieces will look great in that bay. I don't know if "understated" is the right word, but it certainly appeals to my taste as well. I opted for the black hr fuel rail.

This build is getting me hyped for sure. Excited for you bro
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Thanks for the update and for taking pics of the header install. That's some good info that isn't shared frequently enough. I think you've probably got enough clearance. Lookin good bro.
Btw, your thread plus my tax return = me buying parts for the swap. Still a ways off but i might start a thread here once all parts arrive. Hasport mounts are predicted to be at least a month away from shipping. I would bet even longer, but I'm willing to wait.
Keep those posts comin!

Edit: i just remembered what I wanted to ask you. Did u use the jdm starter or did u swap over the dc5 starter? If you used the jdm, is there any wiring mods necessary?
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The intake tube is coming into contact with the counter weight on the shifter cable. First gear will grind unless you really punch it in there and so I need to readjust the whole set up. I was stupid and didn't have the car in 5th gear when installing the intake and so now I've got clearance issues. I also plan on removing the stock battery mount plate that's on the frame to get better space down there. I've heard that's a thing so want to try it. I've already had to remove the battery tray because it was so tight fitting.
That rbc mani points just enough the wrong way to give u trouble, but i think you should be able to clock it or manipulate it enough to make it work. I wouldn't think you should have to touch the battery tray tho? Unless the rbc sticks out more than the prb? In for an answer there if you don't mind. I've never seen an rsx battery tray modified. Maybe your thinking about my post talking about rotating it? That was a hypothetical idea but lmk if you go that route!

I would be super interested in any pics/documentation of your process to make your intake work. I really appreciate your blazing the trail for me and others!
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How's it coming along? Did u manage to make the intake work with the shifter?
A/F ratio is right within 12.6 - 12.8.
Damn son, that's a pretty good base map!
Ooo, fancy. Let us know how you like em
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