Im in the planning stages of doing a K24 swap on my '89 CRX Si. My oly experience with K series has been tuning some later generation cars with flashpro, never really worked on a swapped car, so Ive got a lot of learning to do. Im open to any advice you K swap veterans can endue me with.

But first, here is some back story:

I bought this car from a friend of mine in 2016








He had done a really nice, proper job of swapping a JDM B16A into it from an Integra XSi. IIRC it was a full swap from HMotors.YS1 transmission with a LSD, Hasport mounts, etc. It even kept AC.
Later he upgraded it with skunk2 stage 2 cams, 11.0:1 wiseco pistons, a skunk2 intake manifold, and skunk2 megapower header.



After I got my hands on it, I just tuned it and then mostly just drove it around and had fun with it for a couple years. I fixed a few minor things here and there, like some rust that had developed around the hatch hinges and near the roof moulding.

I got it on the dyno and put down 178 hp. Not too bad for an old B16, but I think I could have gotten some more out of it by playing with the cam timing. The cams were still at 0,0 and I never got around to getting it back on the dyno to dial it in further.


My previous Honda projects had always been turbo, and I guess after a few years of 115 ft-lbs of torque, I was getting a little power hungry. Yet, at the same time, I had gotten really use to having AC, so I figured doing a B20 VTEC setup would be a good way to make some more power/torque and be able to keep the AC in place.

Another buddy put together a B20 short block for me with cast high comp pistons (Nippon?) and ARP rod bolts



I got it all together and in the car using the full Golden Eagle kit







Unfortunately, after breaking the engine in, I found I had the common oil leaks from the head gasket around the oil drains.
I replaced the gasket once with another VTEC type gasket and still had the leaks.
Then I tried a non-vtec type gasket, as discussed in this thread:
https://honda-tech.com/forums/engine...leaks-3355062/

Still leaking oil.
Now here is where **** really starts hitting the fan.

When I had the head off, even the first time after break in, I noticed I was seeing some bad cylinder wear (scuffing).



Every cylinder looks about the same. Additionally, the wear is on both sides, not just the higher thrust wear side where the piston pushes against the cylinder during the power stroke (intake side on these engines).

When I noticed this when doing the first headgasket, I basically thought "thats not good, but its not smoking so **** it" and moved forward. I figured I must have let the cylinders run dry while cranking it for oil pressure the first time I tried to start it. I know the ring gap isnt overly tight, and the tune was so good on the B16 that it was easy to get it spot-on for the B20 immediately, so it didnt wash the cylinders with fuel.

It wasnt until doing the head gasket this most recent time, that I happened to remove the oil cap while the engine was running. Turns out this thing has some serious blow by. The open oil filler felt like the business end of a leaf blower.

I think now that the oil leaking with the new gasket is due to the crank case pressure being out of control.

I did manage to make a quick little ripper video before anything too bad happened.


Making that video was a bit depressing. I felt like I wanted to at least get some kind of evidence of how the car felt so that this effort would not have been for nothing.
But, it is what it is. Time to start the next chapter for this car.

 

Before we move on, here is a little quarantine project I was working on for the B series setup. I wanted to build some ITBs. I bought some CBR1000RR throttles years ago, with the idea of putting some together, but like everything I do it turned into lots of procrastination planning.

The first issue with these throttles is that they are kinda too small. They would probably be fine on a stock B16 or B20, but I expected this engine to put out somewhere in the range of 210+ hp. So from the get go this is pretty much a project for the sake of a project. Mainly just because Ive wanted to get some experience really dialing in an alpha-n tune.

The second issue with these throttles is that the internal bore is offset compared to the outer diameter. This doesnt seem like a huge issue, but I really wanted to optimize this setup as well as I could, so I didnt want some kind of lip in there to disturb airflow. I also was totally opposed to holding them together with silicone couplers, even though that would have been really easy.

Not my pic, but you can see the offset here:




One solution to this was to forego the boots that normally hold the throttles to the head, and instead make a flange that would allow the throttle bodies to sit down into it, and have an offset opening. This would be sealed up with captured o-rings, and the throttles would be clamped into it using threaded rods that held the throttles in compression. I made a few designs like this, one of which was a 2 piece flange that could be cut on a waterjet. This screen cap is a single piece flange that would have to be cut on a CNC mill or router:


I decided this would be too much money to invest in these small throttles. So instead I reworked the plan to use the flanged boots. This means the flange could just be cut out of a piece of flat stock. Something like this:




I had a B16 manifold sitting around that had to be sacrificed




Roughed out the flange on the drill press




finished it up on my buddies mini mill


The fitment with the boots ended up perfect. There was no hand port matching needed here.




cleaned up the cut on the chopped intake manifold as well. It needed to be a bit closer to the flange to get the closest alignment of the runners to the throttles.




and here it is all mocked up



runner length is roughly 22cm with the factory velocity stacks. I intended on messing with runner length with some 3d printed velocity stacks and spacing out the boots from the flange for fine tuning



Finally, here it is held up to the engine



I still havent gotten around to welding it. I figure Ill at least do that, so maybe I can sell it to somebody and let them figure out the rest (throttle cable, IACV, and plugging holes)

 

looks like a fun little crx
good pics and good read about it

 

Thank you!

The Hasport mounts on this car are still holding up great after ~12 years. Ill definitely be pulling the trigger on your K swap mounts as soon as I figure out which transmission Im going to use.

EDIT:
Also learned a lot from Brian Gillespie's videos on youtube. So thanks to you guys for that as well!

 

man that’s a clean crx!

 

Blam!





JDM K24A (3 lobe ~200hp type)
K24Z7 trans

Got my Hasport mounts and a couple odds and ends so far. About ready to drop a bunch more $ on swap parts

 

Heres a little status update.

Had my buddy, Chris, of ODB welding werks (ODBWELDINGWERKS - HOME) come over and MIG in my engine mount and close up some firewall holes with his CNC plasma cut filler plates.



The dude is a wizard with the MIG




Before:


After:


I started messing with the chassis harness and man... **** this ****. Im honestly tempted to just say **** it and go full race wiring with the thing, but I had planned on keeping lights on the car for its occasional street use. Im also conflicted about keeping HVAC control just for the purpose of de-fogging with fresh air, but its a lot of extra weight and extra wiring for something I could probably replace with a rag.

 

Im also working on figuring out the shifter setup, and based on my research, I may be breaking new ground. It doesnt seem like many people use the K24Z7 transmission in general, and those that have do 1 of 2 things with the shifter setup.
1) Replace the selector mecahnism with one from an RSX, then use the standard RSX/"K swap" style cables and shifter
2) Use a bracket to move the cable mounts on the transmission side, so you can use Z3 shifter cables, and either an accord/TSX style shifter, or the Hybrid racing "no cut" Z3 shifter.

Im going to try to figure out how to use the Z7 cables with the existing transmission bracket. I got some brand new cables from Honda, and bought a used Accord shifter for testing. What I found is that the front to back looks like its going to work, but the side to side doesnt quite reach when the cable is mounted on the accord shifter. In other words, the 9th gen (K247) shifter has the cable hold closer to the shifter lever mechanism than on the Accord/TSX shifter.

Here is the 9th gen shifter for reference



What Im thinking of doing is cutting a notch in the Accord shifter like this


Then making a plate that mounts under the shifter, with provisions for holding the side-to-side cable in the right place (55mm further back)


The other option would be drop some dough on a fancy Acuity or Hybrid racing 9th gen shifter, and then either modify it so it mounts in the car in the right postition, or cut and weld on the cars tunnel to make it fit in a good position.




Any thoughts?