for the love of god shawn, you said you’d get to me when you were done. did you forget?
Get to you?
round 2:
I just want to provoke some technical talk here, which is lacking.
My opinion: Liter for liter the k20 is the most efficient production motor in a car on the planet. This is based on what i have seen these motors output, on the dyno and the track.
Keep in mind a stock k20r consistantly puts down more power on the dyno than an s2k and a TON more(30+whp) when tuned. not bad for an econobox.
If anyones disagrees lets keep it technical, show some facts with data.
Peak horsepower shows a motors ability to flow air and make power with a specific amount of air (VE). Honda’s typically make the same or more torque as an equivalant sized motor, and the heads flow so well and carry that torque in the higher rpms so they tend to make more horsepower. peak hp definately is not an end all this is a better motor, but it indeed holds a certain value. now you may be asking yourself what does all this high rpm mumbo jumbo do for me, i just have to wait longer for the power right!? not the case, hondas torque curves are fairly flat as in they have a fairly broad powerband, the torque curve does not peak at redline, generally speaking you will have similar torque at 5000 as you do at 8000. What this does do is allows honda to shorten their gears to allow for quicker acceleration without sacrificing max speed in each gear. remember torque is multiplied, so 2 engines make 160 crank ftlbs, and you are using shorter gears you are going to put down more actual torque to the ground, which means faster acceleration.
shawn brought up strength and durability before, which plays an obvious role in a “which motor is better” argument lol. the strength of the motor is strong for what it is, a high output n/a motor. It does lack certain features FI motors are typically privy to. IE forged pistons, beefier rods, closed deck block. The cranks are forged from the factory, and balanced perfectly, they have no problem supporting any power desired. The motors themselves are still capable of withstanding 400-500whp without issue. The pistons are typically the first weakness on the honda motors, the ringlands tend to give way. The open deck is great for cooling and efficiency, but proves to be a weakness at 600+whp levels on the b series motors, havent seen too much data on the K in that aspect yet but im assuming similar weakness. the k20 is luxury to an extremely high flowing head, which some might argue makes up for its lack of a strong bottom end on a typical in FI motors. the money saved in cams/valvetrain can be better spent on the bottom end.
to touch up on some of shawn’s other topics on what makes an excellent motor:
What about REAL power to the wheels and not marketing jazz? claimed 220bhp, we put down 209whp before tuning and then 230hp at the wheels with tuning stock 2.0 motor def not marketing jazz, more than we made with a 2.0l b series(223whp), with higher compression, and skunk2 pro 2 cams, which are very aggressive.
Torque? mediocre at best, but i wouldnt expect more from a 2.0l
Powerband? believe it or not it is very good
Ability to hold cylinder pressure? not an issue(im assuming you mean without running into head lift issues, etc.)
Stock block capability? inadequate for high boost applications.
(adding one myself) Stock Head capability? unmatched (i wouldnt touch the ports or cams until 800+whp just a set of supertech springs and retainers)
FI or NA? Rotarys count? High end cars count?
wow, awesome post Mike :nod :thumb
That’s fair but being efficient doesn’t make it “better” if you use that word in its absolute meaning. I am referring to hondalover’s reference here too.
Sorry, the 2JZ (to name 1 car) with less efficiency or crank HP/L, is a better motor, IMHO.
Good post. I listed those above as alternatives to the inadequate comparison using crank peak HP/L for any motor, not specifically the K20. Simply using crank HP is a horrible way to compare two cars especially two very different cars.
I’m still giving the nod to the 6G72. :tong
i strictly meant efficient. the term better has a lot of meanings. the 2jz is the strongest production motor made. as in can handle the most abuse. obviously there are some larger motors that can handle more power but arent as strong.
Good. I agree.
rotaries count, FI counts. of course FI easily adds power to a car but that doesnt mean its more efficient if its a higher hp per liter.
Define efficient.
Ford festiva 4cyl. :tong
there are a few different efficiencies, the one im talking about particularly is the engines ability to intake and exhaust air, and make power with that air. it can consume it and/or make more power with a given amount of air better than any production motor.
So why would FI cars not be more efficient? The motor still has to ingest that air?
Also, I am not sure why the emphasis on efficiency. There are many more factors that are more import, IMHO.
i think a turbo car isn’t as efficient because although it is making more power, it’s efficiency rating drops. i think that is how it works…
I am not sure what an efficiency rating is.
But, the FI car is cramming air into the cylinders just like a NA car does just more of it. The car’s IC system should be bringing the temps back near ambient temp before combustion.
yeah like 4 pages ago when you promised to make fun of my car to get off the k20 subject, obviously you forgot. its cool, i can see how important i am. :lol
The K20 requires my full attention. I still love ya. 
i got an idea, i’ve driven a few res type s, so someone here with a stock 3kgt let me drive it so i can feel like ive atleast driven both cars to compare. i dont like all this comparing just the motor crap, whats dose that accomplish? i think its all about what chassis you put them in no?
first of im not an expert on fluid dynamics so take this for what its worth.
it is very tough to compare efficiency on a FI motor and a N/A motor because they are in 2 totally different conditions. the FI motor has air being pushed into it. any motor will have the ability to consume more air with pressure behind it than with no pressure behind it. this is how a 2.0 liter can make 1000whp. how much more it can consume before becoming a restriction, and making power with that air is what im talking about. there will be a point where restriction will build up and the gains will not be as large with the same increase in pressure or flow from the turbocharger. a more efficient motor will have that happen at a higher pressure or flow.
for instance. at the 500whp level on a b series motor, headwork and cams do not have huge gains to be had. but when you are pushing 700-800whp on a stock ported and cammed head now the head is a much larger restriction and there is a lot of power to be free’d up. Sure the stock head ports/cams can do the job but the turbo has to work a lot harder to push that air through the motor. now with a k series you can push 700-800whp worth of air at a much easier pace than the b series. the k series cars are going the same MPH as the B series car with smaller turbos because they can make more power with the same amount of air. since less is being wasted to overcome restrictions.
some factors may be more important to you. but evidently for honda efficiency means a lot. they were the first company to release a 100hp per liter n/a motor, the b16 in 1988. yes only 1.6 liters and 160hp nothing to go crazy over, but 100hp per liter out of a n/a production motor was unheard of in that day, and still not the standard today. And for this to come from Honda a company that typically produced the cheaper cars on the market was unexpected. they were and still are pushing technology forward.
thats a tricky statement. Volumetric efficiency increases. more air, displacement is the same means a higher volumetric efficiency. there are some losses involved, but the gains in power outwiegh that.
ok…thanx for the info man…