dunno maybe this has been covered before
i did a quick search but didnt come up with anything, dont know alot about
f20's but from what i hear there pretty similar to k20's right?

so if there so similar my question is how come k20's have such great potential to make silly n/a horsepower so easily, but the f20 its alot harder on
is it drivetrain lose?, proper parts and r&d hasnt been done?
i hear the k20 head flows amazingly does the f20 not flow as good?

sorry i was just lookin around and wondering
iv been lookin into pickin up an s2k soon, once i finish building my ITR


thanks

 

You have to remember that the F block is older and the K is a good deckade newer.

"Area under the curve."

The K has roller rockers which reduce friction, it has VTC which can rotate the cam relative to the crank, oil jets delivering oil to the bottom of the piston, a cam chain opposed to a belt, and the exhaust is on the backside of the engine bay, optimizing exhaust flow, letting the motor breathe a bit better. This gives a flat torque curve at some parts, which means over the whole powerband, a K20 verse a F20, the K is delivering more torque.
Yes the K does flow better and is also a lighter design, with more engineering and less friction. The internals are machined to tigheter tolerances, which is why a F block could take a 10W-30 oil and a K20 will take a 5W-20. The K is overall a more effecient and better motor. The K transmissions are also a bit more engineered, thus there is a bit less lost in the driveline. All K-transmissions have a "midshaft" to reduce torque steer, tho i dont know if all F-trannies have this too. A K can accept a 5 speed auto or 6 speed manual transmission, and they just didn't make these when the F-series blocks were in the new Accords.

ALSO...the K-series ECU is a big thing. With the i in i-VTEC, the cam rotates relative to the crank, this gives it a variety of fuel mappings. The injectors are better, the head design is more effecient so more of the fuel burns and makes more power with it through less loss.

One BIG thing is DI, distributorless ignition. There is NO dizzy on a K-series motor, there is a coil for each plug, so no spark wires. Using the ECU to send the spark exactly when it wants it is a better design than using a dizzy where the spark has to jump a point through a rotor piece.

With time Honda made their parts better, a more effecient oil pickup, a power steering system that robs less engine power, lighter cam gears, lighter crank pulley, a more effecient alternator, even a more effecient air conditioner compressor to pull less power too.

Honda's game is "volumetric effeciency". How much power per displacement. They were the first to n/a get 100hp/liter in a road car (thanks again DC2). The K is more effecient and gets more HP per Liter than the F.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline57 &raquo;</TD></TR><TR><TD CLASS="quote">You have to remember that the F block is older and the K is a good deckade newer.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline57 &raquo;</TD></TR><TR><TD CLASS="quote">One BIG thing is DI, distributorless ignition. There is NO dizzy on a K-series motor, there is a coil for each plug, so no spark wires.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline57 &raquo;</TD></TR><TR><TD CLASS="quote">Honda's game is "volumetric effeciency". How much power per displacement. They were the first to n/a get 100hp/liter in a road car </TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline57 &raquo;</TD></TR><TR><TD CLASS="quote"> The K is more effecient and gets more HP per Liter than the F. </TD></TR></TABLE>

Eh, you are talking about the TOTALLY wrong motor there bud.

I am assuming he was talking about the F series found in the S2000 (F20c and F22). The motors you are talking about are the F's that are found in some Preludes, and Accords. These F's crank rotation is opposite that of the other F series, they do not have i-VTEC, , put out more HP/L than any USDM K series, they utilize a DIS (distributorless ignition system), and are based on a RWD platform

A stock K20A found in the JDM DC5 IT<FONT COLOR="RED"> R</FONT>'s in Japan puts out 220 crank hp. That equals 110 HP per liter, or hp/L. That is the most powerful K20 series motor available in it's stock form. But it is strictly a JDM motor, meaning, you have to import them to the US.

The F20, found in the USDM AP2 S2000's put out 240 hp SAE@8300 RPMs, and I BELIEVE that the F22 put out the same numbers, but don't hold me to that. That is 120 hp/l.

The USDM K20A3's found in the USDM base model RSX, crank out 160 WHP SAE @ 6,500 RPM's. Which levels out to 80 hp/L.

The K20A2 found in the USDM RSX <FONT COLOR="Red">Type S</FONT> puts out 200HP @ 7400 RPM. Which is 100 hp/L.


So, lets compare #'s

K20A - 110 hp/L
K20A2 - 100 hp/L
K20A3 - 80 hp/L
F20 and F22C - 120 hp/L


Hope that helps, 01-0720




Modified by .Red.EM2 at 1:02 AM 10/6/2006

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .Red.EM2 &raquo;</TD></TR><TR><TD CLASS="quote">



Eh, you are talking about the TOTALLY wrong motor there bud.

I am assuming e was talking about the F series found in the S2000 (F20c and F22). The motors you are talking about are the F's that are found in some Preludes, and Accords. These F's crank rotation is opposite that of the other F series, they do not have i-VTEC, , put out more HP/L than any USDM K series, they utilize a DIS (distributorless ignition system), and are based on a RWD platform

A stock K20A found in the JDM DC5 IT<FONT COLOR="RED">R</FONT>'s in Japan puts out 220 crank hp. That is the most powerful K20 series motor available in it's stock form. But it is strictly a JDM motor, meaning, you have to import them to the US.

The F20, found in the AP2 S2000's put out 240 hp SAE@8300 RPMs, and I BELIEVE that the F22 put out the same numbers, but don't hold me to that.


Modified by .Red.EM2 at 12:41 AM 10/6/2006

you are absolutely corrrrrect.

Modified by .Red.EM2 at 12:42 AM 10/6/2006</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline57 &raquo;</TD></TR><TR><TD CLASS="quote">You have to remember that the F block is older and the K is a good deckade newer.

"Area under the curve."

The K has roller rockers which reduce friction, it has VTC which can rotate the cam relative to the crank, oil jets delivering oil to the bottom of the piston, a cam chain opposed to a belt, and the exhaust is on the backside of the engine bay, optimizing exhaust flow, letting the motor breathe a bit better. This gives a flat torque curve at some parts, which means over the whole powerband, a K20 verse a F20, the K is delivering more torque.
Yes the K does flow better and is also a lighter design, with more engineering and less friction. The internals are machined to tigheter tolerances, which is why a F block could take a 10W-30 oil and a K20 will take a 5W-20. The K is overall a more effecient and better motor. The K transmissions are also a bit more engineered, thus there is a bit less lost in the driveline. All K-transmissions have a "midshaft" to reduce torque steer, tho i dont know if all F-trannies have this too. A K can accept a 5 speed auto or 6 speed manual transmission, and they just didn't make these when the F-series blocks were in the new Accords.

ALSO...the K-series ECU is a big thing. With the i in i-VTEC, the cam rotates relative to the crank, this gives it a variety of fuel mappings. The injectors are better, the head design is more effecient so more of the fuel burns and makes more power with it through less loss.

One BIG thing is DI, distributorless ignition. There is NO dizzy on a K-series motor, there is a coil for each plug, so no spark wires. Using the ECU to send the spark exactly when it wants it is a better design than using a dizzy where the spark has to jump a point through a rotor piece.

With time Honda made their parts better, a more effecient oil pickup, a power steering system that robs less engine power, lighter cam gears, lighter crank pulley, a more effecient alternator, even a more effecient air conditioner compressor to pull less power too.

Honda's game is "volumetric effeciency". How much power per displacement. They were the first to n/a get 100hp/liter in a road car (thanks again DC2). The K is more effecient and gets more HP per Liter than the F. </TD></TR></TABLE>

my head rarely spins while reading posts but yours made mine spin 980degrees...all that time and effort to type out what you posted, being your first post and all...must drink more

 

Chill man, I'm talking basic theory, hes asking why a K is better than a F. At their limit, the K will surpass the F by a lot because the K is a better engine. The S2000 engine that does 120hp/L also revs to 9000rpm. You don't think someday Honda is gonna have a K20 that can do 240hp? Im sure they could, and the torque curve would be a lot bigger. Should you do to a K block what they did with the S2000, youd have an even better engine.

Don't get me wrong, the F-series has proven itself bulletproof, like in that million-mile Accord.

The new Type-S motor does 210hp, by the standards of the 2000 Honda S2000, not requiring a p/s to be run, knocking it down now to 201hp for the RSX-S.

He was talking F-series, he didnt mention the specific S2000 motor.

The F20c in the S2000 is still an F-series block, but thats a special motor, not really interchangable with other F-series engines. For one, the S2000 is a twin cam VTEC motor that uses counter-rotating cams, meaning each spins a different direction, AND has a cam chain, not a belt. Compared to all F-series motors, the S2000 engine is very very different, and not really the same, not to mention it bolting to a transmission, compared to a transaxle.

I'm sorry stating that K's are more effecient than the F was going to bother you that much, no need to chew me out over trifles, this aint a BMW. I guess I have to keep my mouth shut on honda-tech.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .Red.EM2 &raquo;</TD></TR><TR><TD CLASS="quote">




So, lets compare #'s

K20A - 110 hp/L
K20A2 - 100 hp/L
K20A3 - 80 hp/L
F20 and F22C - 120 hp/L


Hope that helps, 01-0720


Modified by .Red.EM2 at 1:02 AM 10/6/2006</TD></TR></TABLE>

umm...well not really a big deal, but its impossible for the F22 and F20c to both make 120hp/liter. They both put out roughly 240HP, so that makes the F20C (that comes in in the AP1, not the AP2) a 120hp/liter motor since it's a 2 liter. The F22 is a 237HP 2.2 L motor making it rougly a 108hp/liter motor.

 

B Serious, thanks for the correction on the numbers. It was one in the morning, and I had woken up and couldn't go back to sleep. Maybe you can let that slide just this once eh?

Redline57: It wasn't a personal attack against you. YOu just sounded like you were talking about the OLD F series motors, which are irrelevant in the boardds designed to talk about the S2000. But I still don't think that a K will ever be as postent as the F series in the AP's. You have 700 and 800 whp S2k's running around. But I PERSONALLY have never seen more than 4 to 5 hundered HP in a FWD Honda or Acura K equiped car. Not saying there is not any out there, I just have not seen them.

And besides, the K20z1(?) found in the 06 RSX'S only puts out 201, not 210 hp.

Like I said Redline57, it wasnt meant to make you mad, or to attack you personally, just thought I should help out a bit on which motor he was talking about according to the forum he posted it in. No hard feelings?

 

Yeah were cool.

And by the way, I have seen some crazy stuff with motors, meaning at their limit. Like I recall an H22 in a Prelude (im saying H but the F-series block is just about the same) crankin 725hp. I've seen 400hp from a D, and hell even over 300whp from a 2.0L B-series block, naturally aspirated!! Its all about how the motor is built. I don't know why Honda chose to tune the F-series block to make that much power, maybe cause its proven itself SO reliable, which it really is. I imagine in a few years if the K-series block gets that kind of reputation, if Honda tweaks that to the level the F20C were, we might just get an even BETTER motor. Still, its sad they are killing the S2000. Maybe in a few years they could bring it back? How bout a K20C with like...300HP and 200tq revving to like 10k RPM. Thatd be freakin cool.

Yea the reason the new S2000 doesnt have 240hp is cause in 05, they changed the HP rating. Motors now I THINK have to have the p/s pump running when they calculate the factory horsepower now. Thats why the new RSX-S is 201hp, not 210, and the new Civic Si that was suppose to be 200 is only 197.

When im talking bout what the beter motor is, the F-series block is still an F, though the casting is different having motormounts for a straight mounted engine not transversely. The f20c has simply been updated with some better features, like carbon reinforced sleeves, moly coated piston skirts, two cams with full VTEC on each one, and counter-rotating cams with gears not belts, whereas on the K, all this new technology comes standard. The F is about done though after the S2k, and the K will do its job. The K will get better onces its upped in technology with maybe cracked connecting rods, maybe offset cylinder sleeves (like in the L-series), and who knows, maybe VANOS type System.
I have seen somewhere a kit to get the f20c into an Elise, and only once seen the F20C mounted transversely in a FWD Honda, though its quite a bit of custom work.

 

Why are you saying a K20A is better than an F20C? I disagree actually.

 

I didnt say a "K20A" was better than an "F20C" I said the K block is better than the F block. The F20C is like the very best the F block has produced, a 240hp motor that revs reliably to 9000rpm. The K hasnt reached its full potential yet. The F20C is a great motor, and probably better than a stock K20A due to things like its carbon fiber reinforced cylinder liners, but if both engines were HEAVILY built, the K20 will outperform. Stock motors, Id rather have an F20C myself.

 

what the..........this thread is confusing.


Lock this bish.

 

and my head continues to spin...sounds like you're regurgitating honda press release articles and marketing ads. Do you really know what you're talking about, new standards for SAE bhp, vanos...

 

Nah I'm not just spitting out terms to sound smart, I know what I mean. Don't lock this thread, its an exchange of information.

VANOS = A system used in BMW motors. What it does is make like...an infinite number of cam profiles...sort of. What it physically is, if you know how a cam works, is that there is a cam, a rocker, and the valve. Rather than have the rocker pivot about a fixed shaft, pretend this shaft is moveable, and its attached to a servo motor. It actually varies the rocker ratio. In simpler terms, at any RPM, this motor changes how much it lets the cam open the valve. Say at low RPM, it can have the cam open the valves VERY little. At high RPMs, it pushes the rocker toward the valve more, so the valve opens a lot. BMW has a motor where it controls the valves so well that there is no throttle body! The throttle pedal goes to the computer and tells it how much to open at any RPM and load!!

Regarding Horsepower ratings, yes, in 2005 the standard for rating horsepower changed. Anyone here old? In the 60s, brake horsepower, or BHP, was rated by attaching the engine crank to a shaft, and like a rotor, and a "brake" stopped the motor, kind of. What this did is tell how much "brake" horsepower a motor could produce. ENgine makers would do things to make the number as high as possible. The engine would be out of the car, with electricity added by an external battery for the engine's revving, so it wouldnt run an alternator. they would disconnect the power steering belt, not run the a/c, have a separate motor run the oil pump, etc. Anything to take a load off the engine and make that horsepower number as high as possible. This was unrealistic, cause in the actual car, you wont be making this much. Well standards changed, and as of 2005, if your car uses a P/S that runs off the motor, even that has to be running while the car's stock HP is measured for putting on the sticker to advertize. When you drive your car in traffic, its running the alternator, p/s pump, oil pump, water pump, so your horsepower to the flywheel is lowered because the motor is spinning all those things as well as the flywheel.

Sorry If i get all technical on everyone, I forget that some people don't know motors as well as I do. If anyone has any questions for me, post em here, or wait like a week or two when I can do PMs on here, I'm still a newb on here and can't do everything yet.

 

IMO, this is a useless thread. Why argue over which is better? We will get nowhere since everyone will have their own opinions. They're both good motors.

edit- but here's some good reading: http://en.wikipedia.org/wiki/Honda_F20C_engine


Modified by Grip King at 11:32 AM 10/8/2006

 

Sir this isnt an opinion, the K BLOCK is better than the F block, theres no arguement. The K is a more volumetrically effecient motor than the F. You can debate over engine exhaust note, or which torque curve you like feeling more, But a K20A verse a F20C, the F20C makes more power per volume, so comparing these two, the F20C is RELATIVELY better to some cause it makes more power. How is this useless though? I have explained the technology of each motor, and told of why the newer K is the predecessor and will be better overall and at the limit because of VTC. When modding cars though, some people go with other motors because of cost, or ease of install, or because they just like how it sounds or revvs. What would you like to see accomplished in this thread? We can talk about valve lash, VTEC engagement, combustion chamber design, Intake manifold flow, torque curves, etc. AT THE LIMIT, the K20 is a more powerful motor. Now both engines being hand built and super modified, I'm sure both could crank out 300 at the ground, but per volume money and effort put into the block, the K will dominate. Now comparing two stock motors such as the K20A verse the F20C, the way you mod them, the F20C is more powerful stock and may respond better at some limits to bolt ons. Ya gotta remember each engine's horsepower and torque curve, as well as the drivetrain downfall of RWD of the S2000, the benefit of its LSD, the tranny, etc. These blanket rules i'm telling you are general and are true, but at each point, you have to go to the dyno. Like same work in each motor, one may be better than the other. THe S2000 simply has the best of the best of the F-series, and is the ****. How may I explain this differently?

 

Some things I have noticed on the whole K vs F situation that other people dont pay attention to:
Stock RSX Type S makes 180 whp
Stock S2000 makes 200 whp
RSX Type S with header and cold air intake and tuning makes roughly 200 whp
S2000 with header and cold air intake and tuning makes 205-210 whp
Ok so the deal is the rsx was more responsive to the boltons right?
Wrong the rsx type s has a poorly designed intake and header from factory while the s2000 header and intake are really very good
All you did with the rsx type s is bolt on a good header and intake now your have nothing better than a stock s2000 ok theres more

RSX type s with cams (must have header and intake to see any real differnece)
an extra 10-15 hp
S2000 with cams (stock header and intake are good from factory so no huge differences here) 8- 15 hp (if you get cam gears you can get an extra 5-10 whp from tuning)

ok so now you have a well built rsx type s with cams, cold air intake, header, and k pro you make 220-225 whp
S2000 has cams, cam gears, header, cold air intake, and aem for tuning makes 220-225

Where is the huge difference people are talking about????

Ok so it is really easy to do a k24 with type s head and make an extra 30-50 whp depending on how it is done
A s2000 with stroker kit makes the same power assuming all mods are simular....

K20A head flows 310-315 cfm on intake at .5" lift
F20c Head flows 320 cfm on intake at .5" lift
The only real difference in the K series and F series is the ivtec
Now for those looking for the best of both worlds (have i vtec in you st2k)
Head swap is being developed at our shop
The head is actually a bolt on, custom chain guides must be made, a few oil passages must be plugged and oil re routed (like ls vtec swaps), and custom chain covers must be made after that it is almost a 100% bolt up
We are in the slow progress of working out the bugs with this but we can assure it is fully possible to acomplish

-James

 

where do i sign up?
ill be waiting for this

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline57 &raquo;</TD></TR><TR><TD CLASS="quote">Sir this isnt an opinion, the K BLOCK is better than the F block, theres no arguement. </TD></TR></TABLE>

I notice you don't have any facts to back that up... typical.

I think we should stick to comparing stock motors since there are way too many options as far as modifications go though.

 

What Makes it better?
It has i vtec that is all
other than that
F20 has all forged internals
All the K's are cast.....
-James

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 01-0720 &raquo;</TD></TR><TR><TD CLASS="quote">dunno maybe this has been covered before
i did a quick search but didnt come up with anything, dont know alot about
f20's but from what i hear there pretty similar to k20's right?

so if there so similar my question is how come k20's have such great potential to make silly n/a horsepower so easily, but the f20 its alot harder on
is it drivetrain lose?, proper parts and r&d hasnt been done?
i hear the k20 head flows amazingly does the f20 not flow as good?

sorry i was just lookin around and wondering
iv been lookin into pickin up an s2k soon, once i finish building my ITR


thanks</TD></TR></TABLE>

holy crap 01-0720. QFT at least the threads you create these days arent all centered around the same question regarding HID's and color output. It was only yesterday where you were asking 10 different forums about the same damn question multiple times even when people answered you and the answer was also in the FAQ in the itr forum!

good job!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline57 &raquo;</TD></TR><TR><TD CLASS="quote">

Sorry If i get all technical on everyone, I forget that some people don't know motors as well as I do. </TD></TR></TABLE>

WTF dude its obviously apparent you know nothing about the f20c engine. i know very little and i can see right through every misguided "fact" you spouted off about it. you seem to have read up on the features of the k20 but you obviously know nothing about the f20c.

i cant belive you said the k20 is more volumetrically efficent. do you even know that means?

and the f20c is absolutely NOTHING like any of the accord F series. nothing... the f20 should actually be called the k20c

 

I think Redline57 should stop rambling about information that's been verbally passed on from him rather than interpreted from first-hand experience with engines.

The F20Cs found in S2000s should never be compared to the older F-series found in Accords.

 

wasn't it also in the oddessey??

 

Chill man, would you like to test me? Or shall I bring my terms down to your level. I haven't "read" **** and am spouting brochure information, I'm educating people that don't know every detail of the F20C, but dont get all **** defending it like its your little perfect motor. The F20C is very very different from other F-series, but check the block casting. It can bolt old automatic accord trannies, and heads. But it is NOT a K, because it does not have VTC or roller rockers, does not bolt to K-series trannys, and simply put, isnt a K.

You wanna know what I know about motors? You wanna know about my firsthand experience and how many engines i've overhauled? Ask next time before making false claims. Ask me insted of assuming. I'm putting out little facts The topic was K20 and F20 power differences, I was trying to explain what the differences are.

Excuse me for using the INTERNET to post information about what I know. Get your ego out of overdrive man. So much for this post, bye.