Is the K20A really that special?

[Sirois]

Hi guys,

I've been going through quite a few build threads etc here and on other Honda sites.

Some cars are getting near 200kw ATW, N/A, still at 2.0L with an OEM bottom end (from some late model Civic R).

Are these legitimate power figures?
How do these motors make that much power? Is it all in the revs?
Are these hyper atmo motors ok to drive, or just shine on the track?

And, are there any weaknesses in the K20a, or things that could've been done better?

[Sirois]

Bump?

[eskimo_firefighter]

Yes the K series is a special motor. It's just a very well designed and built motor hence why its considered as one of the best N/A 4 cylinder motors made. They are a common swap in MX5's, Lotuses and even come factory in the Ariel Atom. They're reliable, make great power for its size and its got a heap of aftermarket support. For a 4 cylinder they make nice power even in the low end which allows it to have nice driveability on the street. Tuners also love it with the engines tunability with the IVTEC system. Was having a chat with a local mechanic the other day who specialises in tuning Honda's and mentioned the tuneability on the cam timing in the Kseries is awesome which allows tunes to add in a heap of power midrange. Something I wish I had in the F20C.

[tinkerbell]

yes, but any 86mm x 86mm engine is special

[Sirois]

And what makes it make so much power? Head port design and iVTEC?

[tinkerbell]

And what makes it make so much power?

compared to what?

a V8?

a turbo charged engine?

what is your comparison to?

[Sirois]

I am comparing it to a naturally aspirated, 2.0 litre, 4 cylinder.
And not so much in stock form (160ish kw is nothing ground breaking for a 2L NA motor), but rather once modified these motors seem to make more power than what I would have thought ever possible for an atmo 2L

[tinkerbell]

more power than what I would have thought ever possible for an atmo 2L

Honda - the Power of Dreams™

so do you have a link to one of these 200kW at the wheels with OEM bottom-end builds?

[tinkerbell]

I am comparing it to a naturally aspirated, 2.0 litre, 4 cylinder.

btw - you are making me feel inadequate, my 2.0 litre, 4 cylinder, CRV engine with CRX head (25 year old design) only puts out 160kW at the treadlies, but i feel that it needs more killawasps to make me feel *special*...

it sure feels special at WOT up a hill...

[Sirois]

I saw it in the members rides section of clubitr.com.au but couldn't find it again.
I believe it was a DC2 with K20 swap.
Rebuilt bottom end but with one of the late Civic Type R pistons etc.
Made a (claimed) 18Xkw on 98 octane and 19Xkw on E85

[tinkerbell]

"18X" is nowhere NEAR 200kW...

i could make 175kW with ITB's, maybe more with bigger cams, maybe more with better head porting, maybe more with lightweight rods, maybe more with different valves, maybe more with E85...

but yeah...

"SPEED COSTS MONEY - HOW FAST DO YOU WANT TO GO?"

the K20 is *blessed* with a few things, 86x86 bore/stroke (and everything that comes with this) is one of them...

the B20 is 84x89, which is nice for low down, but restricts top end... plus its nearly 30 years old...

[wpg81]

What make a k20 so good HONDA ENGINEERING! All b series have it and are awesome, h series also got it, we all know f series has it but k series just got a little more!

[tinkerbell]

B16A = first consumer engine to put out 100HP per litre...

S2000 = 120HP per litre...

Ferrari 458 Italia = 123 HP per litre...

K20A = ???

the Magic of K20A = Hondata K-Pro

[Sirois]

What comes with 86 x 86 bore/stroke?

Is it just an equilibrium of sorts, with stroke, pistons speed, piston weight etc?

[tinkerbell]

What comes with 86 x 86 bore/stroke?

its not over-square and its not under-square,

https://en.wikipedia.org/wiki/Stroke_ratio