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5 years ago the class rules I was racing in basically told me that I could deal with being 80hp down or swap a K24 in. Being a sucker for punishment and reading about 1 other guy who had done it I decided to go for the K swap. The Original plan was to build my own adapter plate, adapters for the engine mounts and make my own header and wire in a Haltech Stand alone. Run a OEM S2000 intake manifold and throttle body. Because the rules allowed 12:1 pistons and head porting and cam changes I went ahead with those items as well. I went fairly inexpensive on the 1st bottom end and managed a RS machine 12:1 cast piston on a Eagle Rod short block shipped to my door for $1500. I spent a bit of money on the OEM RBB head and had team 4 pistons CNC port the head and I sourced some used Kelford 179B cams. OS Giken helped me with the clutch and flywheel setup sending me a K20 flywheel that would work with my OS clutch I already had. My friend Hal at 2g engineering who had designed the IM adapter, and the adapter plate got a spacer made to go between the clutch and the flywheel to put the clutch at the right location. All in I was under my budget I had set out to have a running K24 in the car. OR SO I THOUGHT. I dropped the car off for the haltech to be programmed and a little while later the Tuner called to inform me it wasn't making much oil pressure and had a wicked leak. I came down and picked the car up. upon inspection I found the block cracked on the corner by the oil pressure switch. It wasn't leaking oil it was spewing oil. Whats worse is appeared to be deep enough to be mixing with a coolant port in the block and mixing the two. How it happened, to this day I don't know. The Block was shipped in a cardboard box wrapped up I can only assume it happened in shipping and I never caught it putting it in.
#2
So at this point I needed a block, the plan was to swap everything over to the new block. I managed to pick up a accord block for dirt cheap. I decided to go a little better on the rods and I ordered Carrillo Rods. In my rush I didn't think to purchase new piston rings and I simply swapped everything over to the new block and fired it up. Took it back to the tuner and he had it on the dyno in no time. He mentioned the car acted like it had a bunch blow by. It made 255whp on his dyno with a correction factor of DIN. I was fairly pleased with these results until showed up to pick the car up and found it hard to start, smoked a pretty good amount on start up, enough blow by when cold that I could watch the catch can "breathing" and a huge Vtec Dip that it actually missfired during the dip. It also didn't feel particularly quick to me. I brought it home and stuck it on my local Dyno (which the F22 had made 221whp) and sure enough it only made 227whp. It felt stronger then that but the TQ was up. A compression and leak down lead me to believe a fair amount of my issues were from reusing the rings.
Some pictures and Dyno to this point...
Also took it to a test day at a track and found out I had a bit of an oil issue. Under heavy braking I would get an oil light on the dash and a drop in oil pressure. We filmed a quick video vs a buddy's bolt on and tuned F22. I had the oil cooler sandwhich plate come loose during this event which resulted in a big spin and obviously no oil pressure for a few moments.
here is the video of the little drag race vs the F22
After this event I decided it was time to find some Horsepower. Wondering if I had calculated my header lengths wrong I decided to order a Ballade header as it was now available. After some delays with production on their end I decided to cancel the order and call up ASP. When talking with ASP they advised getting an Intake Manifold from Xcessive and going with a set of Drag Cartel Cams. None of this solved the blow by and low compression but it was worth a test to see if it would make power. I had already bought and built the next motor and had it sitting in a corner wrapped in surran wrap. So what started with "I'll just swap the header". Turned into DC4 cams, custom Intake manifold by Xcessive and a high dollar ASP header as well as a custom VTC gear. Much to my surprise the headers showed up with the exact same runner length and tube diameters I had chosen for the one I designed and built. The good news is this proved I kinda knew what I was doing. Took it to a new tuner but same dyno as above and she showed good gains, all up top though. Made 267whp.
Shortly after this a group buy on a dry sump setup came available from AT power in england. I decided to take the plunge as it will solve my oil issues. I put the dry sump on it took a weekend to get the plumbing all done and it looked and sounded beautiful. Oddly enough all the blow by seemed to be gone. I was very excited to get the dyno results with the dry sump but I finished it the day before a test day at small local track so off it went to the track. 13 laps in I had a fire ball and a clean hole though the block in #4. After getting it home and apart I came to the determination that the #4 piston had fractured (known for cast pistons) and come apart. The good news is I had a spare block ready to go. The bad news was the head and dry sump were severely damaged. I paid AT power to repair the dry sump to their standards and was forced to sell it to put money together to put the new motor together. More Photo's.
#3
So this one tossed the rule book in the trash. Now it was a personal vendetta to get the car to 300whp. So many K series cars out there made 300whp. But most were reving to 9k plus. Knowing friends that tracked the motors and blew up in the 8200-8500 range I wanted to do it at 8k or less. I have come to realize that 300 wasn't as easy a number in a rwd setup as it was in a fwd. In fwd my last motor would likely have made 300 regardless of the low compression. So the next motor was a 87mm bore fresh honda block with fresh honda crank. New of the same carrillo rods and Wiesco 13.5:1 pistons with swaine tech coating. I ran ID 1000 injectors and E85. I didn't have a awesome head anymore so I had to use an RBB head I had on the shelf from one of the junk yard motors. From a old college buddy he knew someone that could do hand porting of the head and had done a lot of the prototype heads for large head companies in the V8 world. So I sent him my RBB head. The Skunk 2 cams had made a splash in the market place as being the new bees knees for cams and they weren't all that pricey. The tuner had pointed out on the last motor that the DC4's were to big for 8000 rpm and suggesting I go smaller. So Skunk 2 Ultra 2's it was with some supertech Beehive valve springs and supertech valves. I had a local machine shop that owed me a favor for building an exhaust on his car assemble the bottom end. Don't rely on favors from people on a race motor. Also tired of the engine flopping around on the stock mounts I bought the inovate mount kit which as a byproduct lowered the engine about 1/2 inch. Which unfortunately made it to low to get a socket on the crank pulley. Put it together and got a rather disapointing dyno result.
So after the dyno I noted in the dyno video that one of the silcone hoses was collasping in vtec. Figuring that's not good for a Dyno I redesigned the intake setup. I needed a Nasa legal Dyno so I took the RS3's off and put the hoosiers on and went to a different dyno near my house. I set the tires at the min pressure by the rules to try to get the lowest Dyno I could. I let it idle with the hood down and got the intake nice and hot. 1st pull was 252whp (same kinda dynojet). Next pull was 251. It kept getting lower. I put the tire pressure back up and let it cool and did another pull just to check and 259. At this point I assumed I had screwed it up with the change in intake. The Dyno Opperator said his read low. So some friends with S2000's also dyno'd there and made the same numbers they did elsewhere. One thing stood out was that the car developed an oil leak. I had solved the oil under braking issue by putting a plate between the timing cover and the oil pan. It looked to be leaking from there. So I pulled it and resealed that. Still leaked, I pulled the timing cover and resealed it, still leaked. It was a tough leak to find because it would only happen once driven hard and the oil was just everywhere afterwards. since the leak wasn't bad I decided to ignore it and took it to sebring. It didn't go very fast. After sebring I took it to the drag strip where it trapped 102.8mph. At that weight thats 232 avg hp. I had managed to pick up a Civic si Head dirt cheap and had started to read of issues with the skunk 2 cams as well as I was worried about the supertech beehive springs after installing the motor supertech warned me that the springs would have a short life with that large of a cam. The tuner had also said "still to much cam". So I contacted 4 piston and asked em for a custom cam for what I was doing and sent them the si head for a Pro 156 port job. I had planned to swap the head and cams one weekend and be back at it. During that time period the car started to eat start motors. like 10 starts to a startermotor. I also pulled an oil sample and sent it to black stone. Not expecting any bad news on my 50 mile old engine. I swapped the head and cams (and starter again) one weekend and then got the oil sampled back. Blackstone reported large amounts of bearing material in the engine. Some quick googling showed lots of guys that through a rod shortly after receiving oil reports similar to mine. I pulled the pan and took a look at the rod bearings which all looked good as new. At that point I noticed the oil leak was coming from the cradle meaning the engine had to come out. Thank you engine builder. I also noted that I had a ton of crank walk. Hence the strarters dying. At that point I could see that several teeth had been chewed off the flywheel too. Thrust bearing appears to be installed incorrectly causing the play. So much to my dismay it was coming out torn down and rebuilt. It also kinda explained the poor dyno, poor sebring times and poor drag strip mph.
#4
After talking to some other guys it looked like an 87mm bore K24 isn't really a K24.... it's a K23.5 which really isn't a huge step in displacement over a F22. The K gets some advantages, It's easily rebuildable, parts are cheap the block is taller and it has VTC. These are all really nice things. But it was time to stop messing around. After doing some Math I had xcessive build me a longer spacer on the intake manifold as well as bore the whole manifold to be a different taper. The inside ports are smaller. After having non-stop issues with the flex fuel sensor talking to the Haltech I decided this would be a race gas motor. I also had a custom ram air radiator built so the intake tube goes through the radiator for fresh air and a bit of a ram affect at speed. I insulated the inside of the box to avoid heat soak. I decided to go with the 4 piston long rod short piston setup with their 18mm tool steel wrist pin and sleeved and bored to a 2.5. OS giken came through with a custom K20 flywheel that was 4lbs (14lbs after I bolted up the spacer). My adapter plate had been fairly worn from all the previous in and outs and 2nrs of Springfield sourced me one of theirs in a pinch. Also changed the oil pan baffling around around using a combination of baffles to solve any oil starve. VTC is no longer conservative leaving wiggle room. The Engine measured to 33 degrees max safe VTC and my pulley is machined to 32 degrees. I'd still like to hunt a slightly lower RPM TQ peak but not at the cost of taking it apart again. The better rod ratio should make more RPM a bit safer and we spun it to 9k on the dyno it made 313whp. Last trip to the dyno the motor sat there for 5 hrs idling and did 34 pulls in that time.
I had loads of RPM pick up issues on the dyno so the 9k pull only shows MPH. Sorry about that. At 8000 it just touched 300whp. It's been a long road to that number. I took it to the drag strip with a 8k rev limit. I needed 5th gear to go through the lights which I'm sure hurt trap speed. At a full tank of gas and an extremely heavy (52lbs) battery it weighed 2930lbs with me and trapped 106 mph on a 90% humidity night. I've got tires that will allow me to go through the lights in 4th gear now and I'll bump the limiter for the next visit as well as put a normal battery in and a non-full tank. I think 110-111mph isn't impossible. Just waiting on a cooler less humid night. Hope this can serve as valuable info for anyone looking to do a similar swap.
Last edited by Mrsideways; 07-28-2017 at 02:47 PM.
I've had my K24A2 swap done, on the street no issues, however first track day. around 10 laps in, I developed a fuel leak. the fuel feed line where it bends 45degree into the banjo fitting to the fuel rail. Cracked right here.
Couldnt find a replacement part from Honda, so opted to reweld this crack.
Went back to the track, and got a solid 50 laps in before another whiff of fuel. I cant remember if it cracked near this bend again, however fuel was spraying everywhere at the banjo bolt. New crush washers were used on the first repair, however it looks like it was spraying fuel from here.
My setup is:
Hasport K Swap mounts (installed on highest level)
Kmiata S2000 Intake Manifold Adapter
completely stock S2000 intake manifold/tb.fuel setup
My thoughts on this revelopement of fuel leaks on this hardline is; the feed hardline has shifted away from the engine, and towards the fender by the thickness of the Kmiata plate, as well as the height difference the K24 has opposed to the F20. Given track conditions provide maximum vibrations compared to street driving meant the fuel leak issue I have.
Sorry for the bunch of info above, but I thought I share my experience, and also enquire on your fuel rail setup. Looks like you are running a flexi line thus having no issues on the hardline...
I've had my K24A2 swap done, on the street no issues, however first track day. around 10 laps in, I developed a fuel leak. the fuel feed line where it bends 45degree into the banjo fitting to the fuel rail. Cracked right here.
Couldnt find a replacement part from Honda, so opted to reweld this crack.
Went back to the track, and got a solid 50 laps in before another whiff of fuel. I cant remember if it cracked near this bend again, however fuel was spraying everywhere at the banjo bolt. New crush washers were used on the first repair, however it looks like it was spraying fuel from here.
My setup is:
Hasport K Swap mounts (installed on highest level)
Kmiata S2000 Intake Manifold Adapter
completely stock S2000 intake manifold/tb.fuel setup
My thoughts on this revelopement of fuel leaks on this hardline is; the feed hardline has shifted away from the engine, and towards the fender by the thickness of the Kmiata plate, as well as the height difference the K24 has opposed to the F20. Given track conditions provide maximum vibrations compared to street driving meant the fuel leak issue I have.
Sorry for the bunch of info above, but I thought I share my experience, and also enquire on your fuel rail setup. Looks like you are running a flexi line thus having no issues on the hardline...
Mine is an 06 with a returnless fuel system. I know what your talking about that cracked because while mine still had the F22 in it the rail cracked during a race right there and almost burned the car down. I'm running all K series stuff with all AN fittings. I bought the fullblown adapter to converte the stock fuel line from the tank to a AN fitting and then bought the skunk 2 rail and took the banjo bolt out and got an adapter at ace with fuel rated teflon tape and converted that to a AN fitting. I also put a T in line so I can just take the cap off and screw on a 5 ft AN line to a gas tank and run the car till it dies to drain the fuel tank quickly. The Stock S2k intake i'm 90% sure was the massive restriction that kept the first motor from making any real power. Call up Rich at xcessive and buy his 50mm manifold, add a 2 inch plastic spacer and you will be amazed how much more power it will make then you can use all K series stuff for the fuel system. I was going to have him make one for the F22 but no one seemed to be that interested.
Ian
If you could of, what would have you done differently given a second chance?
Tossed the rule book in the trash from the start, and not paid any attention to what people say makes power on the internet. Big thing I've learned is the internet is wrong 100% of the time. It's all marketing hype to get you to buy product. I think a Stock bottom end K24a2 with a K20 head (not legal for the class I was building to) with a Good manifold kept to sub 8000rpm would make 260ish whp nicely all day long with zero problems. Making big power is big money and really flirting with reliability. A supercharger or a turbo would have made 300whp without batting an eye. If you do the Math I'm making around 150hp per Liter. No production N/A car does that.... why do you think that is? No company wants to be on the hook for the warranty on such a high strung motor. Yet there are tons of turbo cars out there with nearly 200hp per liter with a 36,000 mile warranty. So I think a smart person would do it and make 110-130hp per liter and have great reliability for years and be happy. But at a certain point I was just thinking damnit I'm making 300whp out of this thing. I'm fairly certain from talking to the guys at 4 pistons that my motor at 300whp at 8000rpm isn't THAT high strung and should be good to go. But spinning it to 9k to make 313..... it's not gonna have a long life so the 9k was a dyno pull and a couple of drag strip passes. 300whp on 2.5 is still with a 17% drivetrain loss 140hp /per liter which if you think about it, a Ferrari 458 is only 124hp per liter. Sean's ITB AP1 is making 136hp / per liter.
Last edited by Mrsideways; 07-31-2017 at 05:56 AM.
Thanks for sharing all of this! I've been flirting with the idea of a K24 swap. Mostly because I'd like to have some more torque and power on the street, and because K24s are more plentiful so when I do blow a motor at the track I figure maybe it won't be as bad as they are cheaper and easier to find than the F's. But the car is mostly set up as an STR car for autox and just fun for track...really any real power bump will throw me into FP for autoX and well...not sure what class it would end up for TT...hopefully stay in C.
It would be fun to have ~280hp and 190tq to play with, just not sure its worth the headache or throwing myself out of any sort of competitive class.