I own a 1993 Prelude and wanted to see if there were any K series Prelude owners here. My current plan is a ~13:1cr N/A 89mm x 99mm K series motor with ITBs, SSR-DTR Race header, and the cams are yet to be determined.[Something aggressive; IPS/Go-Power?] I will be using a Hasport kit, Hondata K-Pro, and the trans will be a TSX 6spd with an M Factory Final Drive. This is going to be a 2-3yr project, built for Track Days and some street driving.
TSX Longblock with trans
K20A[RSX Type-S head]
The research has been done on K series motors. But it seems like K series Preludes are still pretty foggy.

Before someone says search, this seems to be the only thread on K-Ludes I can find.
https://honda-tech.com/forums/honda-prelude-4/hasport-have-developed-kseries-into-bb1-92-96-prelude-chassis-mount-kits-2172012/

 

Definitely go through with it, sounds good. And yes info on k series in a prelude is far from just Google-ing it up and it'll come up in the first ten results. Keep us posted. Any plans on how your going to do the shift cables for the TSX?

 

Weight isn't an issue when you have well over 200wtq. Car will be in the 2500lb vicinity. Driving a Civic isn't an option. Have you driven a Civic? Its like a coke can on wheels.

At work, Honda-tech is pretty much all I can access, and when I'm home I have so little time to use the computer.
I haven't gotten into the shift cable issues yet. I just know I am stuck with either a USDM Accord/TSX trans which has the poopy gearing, but the M Factory FD will take care of that. The other option I have is to find a EuorR trans[ATR uses a K20] which has the same gearing as the newer RSX/CivicSi trans. From what I have read and been told by Hasport, their kits cannot be used with the RSX/CivicSi trans. It has also been mentioned that you can use the TSX/Accord trans, with RSX/CivicSi guts. M Factory has plenty of option for FDs, so based on my early calculations, something in the 5's will be the selection.

 

I have an article in one of my mags that walked you through the Kseries mount kit Hasport created. It was a green 4th gen with a K20 in it, I would be all over that if I had the time/money.

 

I'm anxious to see this go down......
I would normally try to talk someone into just building an H series......but enoughs enough with them.
An H just can't compare to the K when all things are considered.
The extra 50whp you can pull from a K build over an H, is well worth it.

 

its been done.. https://honda-tech.com/forums/showth...ht=k20+prelude

 

It doesn't seem like anyone has pushed the envelope with a K24 build though. I wouldn't waste the time or money swapping a K20 into a Prelude. Cheaper to build a K24, and better results.
I noticed that was from 2006!

 

That was my thinking, why would I swap a 2.0L into a Prelude?!
I will have to contact him to find out how he used a K20 trans. Hasport told me that with their kit, you have to use a K24 trans or a EuroR K20a trans.

 

See if 2point6 can help. I know he was part of the developement for the K into the 90-93 Accord. I'm sure he can share some trials and tribulations with you. He has done Master Work with H series motors, and I'm sure nothing has changed as he's moved into the K world.
I love the K, but the $$$ has always swerved me back into H world. If the money is there, do it. 350whp seems like a written-recipe with K series setups these days. I would also look into E85 if you're really aimed at higher compression. We have it every 5-10mi in Chicagoland.
for the idea of using the SSR-DTR header.....

 

On a roadcourse, a great driver can easily overcome 500lbs of weight difference.......
Sounds like its going to be one hell of a fun setup!
for NOT selling out on the Prelude.

WOW......just WOW! This is a similar build to what you're planning; 90x99@13.5:1 with Go-Power Race Cams. Looks like it was on its way to making power past 9500rpm.

 

This is an 88x99@13.7:1 with Toruku cams on 110oct. Cams seems a little inferior to the Go-Power cams.

 

Dynos like that are why I am excited about this setup.
I may go for a 90mm x 99mm.
It seems like the top dyno is evidence that a built K will make 30-50whp more than a similarly built H. And 9500rpm? For a 2.5L-----just sweet!!

 

Well, ground up build will be the same; pistons/rods/cams/itbs/header. Sure it takes more money to get started, but another 30-50whp over a similar H build seems awesome to me.
I think the real Idiot K series guys are the ones that just buy a stock K20a/K20a-R and install it......From what I can tell, you can save $1-2k by going K24 and the results will be golden. Sure that K20 has better potential than an H22 when it comes to bolt ons, but $5500 for a motor/trans is out of control.
$2000 TSX motor, $1000 K20 head, $1000 K trans
Seems like $1500 cheaper and more power/torque.

 

build ideas like this are exactly the reason i havent abandoned my prelude yet. everyone in the world can scoop up a hatchback and throw a B/K into it, and its still a civic.

i love the prelude chassis and i love the H motor -- no offense to the OP.

as was said earlier, the prelude can be brought within 500 lbs of most civics and a great driver in a capable chassis can make up that weight.

 

Nice, I hope to see all this done. I was thinking about the power that could be made from using a K24 in a 4th gen, K20 would be a waste. A friend had a RSX-S and the 2L just didn't put out enough torque and the cars weigh about the same.

 

let me get this straight though, if you're using a K20 (RSX-S) head, you could--or would ideally use--any K24 block...which all came in elements, accords, crv, tsx...right? wouldnt you want (for cost reasons) to snag one out of something other than the tsx as that engine was essentially the motor that you are trying to replicate? or am i somewhat off?

 

Krelude: that sounds like a cool project. Good luck and keep us posted. I'd really like to see you succeed!

 

Hey now. Don't make me go over there and kick your ***! lol.


I can attest to the capability of the 4th gen Prelude on a roadcourse even if it's a heavy pig. My FWD Prelude, with some weight reduction, on stock suspension and less power is just as fast as mildy tuned S2000s at my local track with competent drivers/rubber. I've never seen any Civics turn any decent times at that roadcourse (I guess they're all at the drag strip pretending to be fast with their little turbos).

I've found that 180+wtq really helps get the drive out of the turns but in order to keep up in the straights you'll need a bit of power on tap to keep ahead of the other cars with better power:weight ratios.

As for K-series being revved to 9500 rpm I think that those numbers should be taken with a grain of salt. Drag/Dyno Queen motors are have far fewer hours of abuse than a road racing miles. I suspect that if you seriously intend to rev a 99mm stroke to 9000+ for hours of track time then you should work very hard on making everything more relaible: lighter components, wider rod bearings, stronger materials with a hell of a lot of attention to proper oiling and cooling. I'm not sure exactly how easy it is to get 300+whp on a sane budget, but I know for sure that 265whp/210wtq is pretty "cheap"/easy to get.

Good luck with the build, be sure to post pictures.

 

You're completely correct. The slight upside to using the TSX setup is the desire of the internals by other K series users. Buy TSX K24 and sell the rods/pistons/crank[I plan to use a brand new crank from Honda, ~$200<--which was a shocker, I get Honda parts 10% over cost]
I have basically found that the more parts/extra parts the better for this swap. I may end up buying a CRV/Element motor, but part of me wants everything to be from the same Longblock+trans. Possibly me being a little quirky, but it makes sense to me. Everyone knows you can't pass on the right deal, so I will see what happens. As soon as I find it, the plan is to strip it down and send it out for sleeves. I am still slightly debating a 90mm, but at 89mm I have room for the future{god forbid I have an issue, but it is what it is}

As far as revving a 99mm to 9500rpm, I would never imagine that on a consistent basis, but the idea of being able to walk a gear out a little further for a specific corner is nice.

Pirate; Thanks for the insight, I have seen your setup pop up here and there! I like it! I've also seen your G type setup, and I really like that too!

As far as sane, this build will be somewhere between SANITY and INSANITY, leaning a little more towards INSANITY. I don't want to sound like some interweb nerd saying money is no object, b/c of course it really is, but this is NOT being done on some kiddy budget. I am really counting on buying some things used, so as I bump into some nice deals, I will buy things. I expect we will see a surge of people giving up on K series projects in the near future. In my conquests, I have found a lot of kids talking about sitting on K series parts planning for a build, but complaining about being broke! <--Always a nice combo for someone like me looking for some deals to ease the K series Pain!

I don't want to get everyone's hopes up that this car will be on the streets/tracks K24 screaming by 2010. Reality is there is more to this project than just building a motor and installing it. My Prelude still needs some interior removal attention, a cage, and seats. 2-3yrs is conservative.

This isn't going to be some 1000 picture project thread thats bumped every time I buy a piece of the puzzle. I just don't have the time to keep it up like so many of you guys do. There are some great project threads here, and I know I can't compare to them. What I can promise is an occasional thread bump with a picture or 2 and some progress updates. This thread may go several months without being touched, and you may log on to see some new goodies! I've never been a Forum nut, but I know what goes down in cyberspace. Lots of useless info and sorting through miles of threads to answer a question. There is some realy good stuff floating around though, and I intend to maximize this. After reading as much as I have, I can tell you this. I know this isn't going to be cheap & I fully understand what I am getting into!!

None taken. I absolutely love the Prelude and the "H". I have owned my Prelude since the days where every kid with a few $k was buying a B16 swap for their random Civic that came with a D, and was still falling short to stock Preludes with a decent driver...Every one of my friends was driving a Civic & Integra, I showed up at the meet spot with a Prelude. All they could say was; Aren't they REAL heavy? My response always was; thats why it has a 2.2L not a 1.6-1.8L. The power to weight of a Prelude much outweighed the extra few hundred pounds it carried around. Usuable power below 5000rpm was something no average B series could take on. Nobody was doing B18R swaps, nobody was doing built Bs, nobody was doing H into Civic swaps.
I have been debating a BIG BUILD for awhile. My 1st intention was a 89-90x95-97 H. Reality hit me, for some extra money, you can have the best! In the end, a well built K will always make more power than an H......$$$ is what sets them apart. You will always pay more for a built K than a built H.

 

WOW.....holy novela!
Seems like you know what you're getting into......

 

that's my mentality 100%. at this point though (for me), i'm sticking with the H motor because i just feel like it came and went and it's just forgotten at this point (among the masses). sure people still work with it, but not to the extent that people are still working with the B, or even D for that matter.

to me, a civic/integra just seems like a 'shell' to put a great setup into, where a prelude is a great chassis that you go out and find a motor for...

 

I'd love to do a K24 hybrid engine in my track car, but I have so many other projects going on right now. I certainly wouldn't mind hearing about updates to see how things are coming along. Now if I could just find a K24 cheap...

 

I'd be interested to see how the weight distribution would change with a K24 swap since you'll be moving the "heavy" side of the engine/trans combo to the right side of the engine bay.

I also like the engine geometry and internals more on the K series (roller rockers, head design, block design, etc) than the H. However, I am very happy with my current H series. I just go back and forth on the cost to build another, stronger H22, or going with a K series swap.

BTW, what year model blocks and heads are considered the "best" for doing a K24 bottom end with a K20 head?

 

I'm not concerned with the added expense because this car will be with me forever. NirVTEC is right though, a turbo setup doesn't suit my wants/needs.
Sure 400-500whp is nice, but if you don't have the tire size to back it up, its tough to use except for straightaways. It would be like trying to use that much power efficiently on street tires, drag racing. Sure it can be done, but there's wasted power, and lack of reliability concerns.

I may have to address some suspension changes when the time comes. I have Ground Controls right now and I can always go with staggered rates if need be to rebalance the car. From what I can tell, the engine is lighter, so thats a plus when it comes to overall weight distribution.

As far as the K24, if you're planning to change pistons anyway, you can use any of them.....PRICE will be the SELL quality there. If you're going to use the stock pistons/rods, the TSX seems to be the ideal donor with the highest compression of any of the available K24. The CRV/Accord/Element are all below 10:1 and the TSX is 10.5:1 iirc.(TSX=K24A2) (CRV/Accord/Element=K24A4) iirc I have a lot of numbers in my head right now. I think you get the idea though.
As far as the head, the 06+ Civic Si has been recommended, although any K20 head NOT from the 01-03 Civic Si(160hp version) or Base RSX will be usuable for this type of build.
Think of it like this;
If you want to buy an H22 to use in stock form, you want the TypeS/EuroR, if you're going to build it anyway, you use whatever is the cheapest in the best condition.

I hope that helps. I will share as much knowledge as I have, and as I learn more I will be able to answer more questions. After over 10yrs of H series, its a nice fresh breath to read about something new. I have never learned about Bs or Ds, and have been resistant to Ks until now.
It time for the K! The bottom end is the easy part(or hardest if you want to talk about bearings/rings) as the K and H are just motors like anything else. There is Bore/Stroke & Compression. The head is where the magic will happen in the K and I have to say every EXTRA HP that the K makes will be due to the head, and tunability via KPro. Truth be told, I haven't found anything THAT special about K series bottom ends. You read about people boosting them, but people have boosted H series for years. Lack of available tuning was always an enemy of the H series Turbo Applications. These successful STOCK K series guys aren't tuning with a $100 VAFC & FMU, they're using ~$1k worth of Hondata to get there.
Ok ok ok. A 99mm crank is damn great!!! There is a 97mm option for the H though. And of course those CHEAP strokers that Crower sells for $4k.
Sorry, I still can't get over that I can buy a Brand New K24 crank from Honda for $200. The H series crank is $600-800 depending on which H you go with.

 

Too add, please if you have any corrections for info I have supplied, correct me. I don't know as much as a lot of people here and can easily get #'s flip flopped.
I spend a lot of time with my posts/replies, so I feel like it should be right, but who knows. Mistakes happen, and bad info is a reason I have stayed away from the forums as much as I have.
Although my searches haven't turned up much K-Prelude info. Looks like I am going to have to rely on "others" K series reasearch and the few that have done Prelude/Accord Ks to help with the install.