I'd go 2.5/2.7 F series before spending time and money on a swap. You get factory weight balance with the f series motor and no worries about problems from the swap (bad welds, horrible clearances, mix and match of parts, etc).

An na 2.5/2.7 makes Plenty of power for the s2000, anything more and your just looking at a highway beast (but some are looking for just that ).

To me, the ideal s2000 will make around 300whp/200wtq in an na configuration.

 

Let's sum things up.

Good 4 cylinder motors for a swap:
None. Why bother? It's different, but there's no point. None is significantly easier to mod or makes significantly more power. Being different is nice, but IMO is not reason enough to do a $5-10k swap to then be left with a stock motor that is roughly the same as a stock S2000 motor. I've gone through this thought process in my Monte Carlo with my LQ1 (3.4L DOHC V6) versus the L67 (3.8L supercharged V6). Things never wind up looking good for a similar swapped motor unless it is a SIGNIFICANT upgrade.

Good 6 cylinder motors for a swap:
NSX 3.0 or 3.2
BMW M3 inline 6
TVR speed 6 4.0 L - 380 hp, 349 lb-ft, 7800 rpm redline - all aluminum, dry sump, etc
RBxxxxx
2JZxxx

Good 8 cylinder motors for a swap:
LSx

Good other motors for a swap:
13B and 20B

Tim

 

Finally someone who thinks the way I do.

 

Right now without cams for the F20/22 that work well (toda's don't, spoons don't, and BC sure as hell don't), the K-series has some real potential that the F-series can't match. Not to mention iVTEC absolutely makes a difference.

You guys who think it is a step down to go from an F to a K need to get your nose out of the air...IF the K had been ready in time, I bet it would have been the engine the S2k would have gotten instead of the F. It's a freaking engine...potential hp/tq is what matters not price of the car it was used for. Hell, the LS1/LS7 design dates back to the '50s and is used in TRUCKS, but that seems OK to use because it sits in a Vette! And you want to talk about which would be more difficult to make work for a swap...a Chevy V8 or a K-series...please.

One more plot of an na k-series build (k24/k20):



http://www.k20a.org/forum/showthread.php?t=18920

 

What's the point?
I commend your abilities (cuz I can't even dream of such swaps) and your ambition but honestly what is the point? You already dide a 2jz swap and that will solidify your abilities in my head, but doing a K series swap just for the sake of doing it.. I dunno.
I'm a supporter of the K series motor (even though I owned the K20A3) because I believe they're great powerplants, and the new SIs are just cleaning house. I also agree that the K series motor isn't below the F20C since they use a lot of the lessons learned from the development of the F20C (car manufacturers tend to do their trial and errors with their lower production cars and take those lessons to their mass produced cars), but I feel one of the S2000's endearing qualities is its motor.
I dunno, perhaps when the S2000 is discontinued and lower mileage examples get harder to find, I could understand this swap since it will give owners an alternative to finding an f20c but until then swapping in a motor that is marginally better (if better at all) is just pointless.
If you're going to do it and follow your idea of keeping it Honda- RDX motor, factory turbo. Oh and then get the certs necessary to make it legal here in california (should work... new Honda motor with all the smog equipment... but perhaps having a bigger displacement may play a role...).

 

I would love to put that in my NSX

 

A blown Hayabusa motor.

 

This is where im still leaning guys, this guys not just talkin, showing dyno's , this is great info. Im game for anything, i live to be different, its fun as hell, and the attention is good for my business. But am very curious to see this k20 in the s2, the wieght is the exact same!! Thats the most critisism ive gotten over my 2jz swap, so i feel that wouldnt be an issue here. The K20 seems to be affordable, and puts down great torque numbers for its size and displacement. The I-VTEC is awsome how it works, Honda's up to date technology in the s2? Why not, its basically the same as the freakin F20C guys!!! Just has a few more goodies . This is not a brainstorm to get every f20c owner to swap for a k20, just curious to see how it performs. And cost wise, how much price difference would it be to get hp gains compared to the f20. Maybe none, but maybe a big difference too.

 

Also remember guys, there was no point to building the 2jz s2000, just did it for fun, it just turned out to be the fastest s2000 in the world! But that wasnt the reason i biult it. If you knew me you'd understand. I did this because i can. And its fun as $HIT to drive! People that ride with me sometimes complain of lightheaded feeling, and have to slow down, when i show them how hard it pulls. I guess if any point, it was to see if i could get my s2 faster than my 850hp 94 supra! And it is. But the only reason i want to swap the k20, is because i know i can do it. And it doesnt seem pricy either. And its one of the most advanced engines out there, and has lots of potential. Thats enough reason for me, and its keeping it all honda too!

 

And PLEASE!! Are you serious??? That comment almost had me on the floor!!! HELL NO!!! OMG that was funny. Thanks for the laugh, i needed that!