BLUE EVO702

iTrader: (2)

^^^not stock internals,22psi is tooo much for the b and k series...

Matt - PURE Tuning

K20 internals can handle 22psi. Even 30+ with headgasket and studs. I would put one against a 4G63 any day.

Best thing about the K motors. The I-vtec allows you tune out knock sensitive spots (adjust dynamic compression on the fly), and still make big power numbers with pump gas and high compression ratios, boosted or NA.

8UpUrV8

iTrader: (9)

Sweet. Point well taken. Much better explanation than "its better cuz the vtek!!!"

riceball777

iTrader: (33)

stock they are made to be all motor and are not as strong as the 4g63 and cant take much boost. but if both motors were built with low compression forged rods and pistons the honda motor are much better and will make more power. in general they have much more potenchiel in power production compared to the 4g63. there heads flow way more, have a much high VE, are more efficeant and are far superior to the 4g63's head.
the b seris heads already far superior to the 4g63 and the k seris take it even further with the ability to controle valve timing on the fly for optimal timing and overlap plus it still have the provem dual cam profiling of vtec.

but there is simply no traction in fwd. on pump gas with only 400whp my integra has absolutely no traction untill over 70mph and only has traction in 4th and 5th gear. basically good for nothing buy burn outs and high speed freeway pulls.

the evo is still a better car than and fwd honda

mchuang

iTrader: (11)

Riceball where are you getting this head information from, that the B series head is far superior to a 4g63. Hate to tell you, but that information just isnt so. Here is a 4g63 head flowed by cosworth stock and modified. Scroll down to bottom of the link. http://www.vividracing.com/catalog/p...ducts_id/19113. The 4g63 shows to flow around 282cfm stock on intake and 257 on the exhaust.

Here is a b16 head flow test, which is known to flow better than the b18c head at higher lifts. If you notice, even ported the b16 does not come close to a 4g63 head.

http://www.chrracingproducts.com/CFMnumbers.html

Now a k series head flows better than a b series, and flows a lil better than a 4g63 on the intake side while stock, but the exhaust side 4g63 owns the k series head and once ported the 4g63 owns the k series head on the intake side also http://www.k20a.org/forum/showthread.php?t=1519

Dont miss inform like that man come on put some facts up first to back that claim up. I love hondas, but I know the 4g63 is a good flowing head.

EvoBig16G

iTrader: (63)

wow i am surprised the 4G63 flows just as well as the K20Z1 engine.

I guess MIVEC 4G63 is a better engine than K20Z1 I-VTEC in terms of bottom end strength and head flow

trinydex

iTrader: (12)

where were you with this in that other thread about why hondas make more boosted than evos

mchuang

iTrader: (11)

Lol well I didnt see anyone say hondas head flow more than a 4g63 head until now. I think the other thread was mainly about compression, but in this thread it was bluntly stated that a honda head flows more which is surely not true. I would love to see the comparsion of a gen 1 4g63 head vs a evo 4g63 head though.

trinydex

iTrader: (12)

no... i think the other thread had a lot of people saying the head design of the hondas was superior and ve was better hence better flow when boosted...

now i really HAVE to wonder why they make more power at less boost with similar compression... (or just think that's a myth and it's all the higher compression that only one person claimed "was x:x.x")

riceball777

iTrader: (33)

hondas head design is simply better due to vtec and they have a high VE. Of course your going to have a better power band and make more power when you got a cam profile for under 5k rpm and a compleately cam profile for over 5k rpm

DarkEvo

I love this debate....i was a hardcore honda boy before the evo...had all the needed internals to turbo my gs-r but i backed out b/c i new there would be huge traction issues. the teg would have been alot faster then the evo but no teg can turn heads like an evo does and what fun is it when you can't really floor it until you are well into 3rd or 4th. Honda motors are awesome...thats why i keep one as a daily driver.

p.s.=i do sometimes regret it

mchuang

iTrader: (11)

Honestly I think it is all about combination, as far as parts, turbo sizing for motor, tuner, comp ratio, etc. Vtec and turbo on the top end also is one hell of a combination as well. We have to keep in mind though honda motors produce less torque than the 4g63 also, well at least the b series.

Ted B

iTrader: (6)

FYI: Those numbers weren't made at a pressure drop of 28" H2O, so they are useless and potentially misleading. Be advised. As to why this would be done that way one can only guess . . .

The intake side of that K20 head, when ported, is an absolute monster.

iTune

iTrader: (3)

i was a k-series boost pioneer...and my knowledge in this area is very extensive. I was one of the first to boost the K20A2 and also was one of the first to test the GReddy turbo kit for the K20A2 using a mitsubishi T517Z turbo. I worked closely with Hondata(there were several of us testing) in the development of the k-pro, which is the best engine management you can have for any k-series engine. I know exactly what it takes to make big numbers with this motor, stock and built. I can tell you this, there is not a single inline4 in the world that is more engineered than this engine. It has a better VE, a better head design(cams, ect.), better combustion chamber design, better bottom end design(minus the rods and pistons), internally balanced crank that can handle more power than you can throw at it in stock form(the whole rotating assembly is balanced from the factory), better block bracing....under piston skirt oil squirters, i mean the list goes on and on! Some of these things the 4G63 does have, what the two engines share is very old school in design.

The k20a2 can make more than 500whp in stock form very safely with the correct parts and of course, a good tune. It's been done time and time again and very few people have had failures. The ones that did were mostly caused by bad tunes or improper protection protocols(i.e. lean protection, overboost protection ect.) or from running the engine at too high of a engine speed(over 9000rpm). This kind of stuff happened very rarely, but can happen to not only a 500+whp engine, but a 250whp engine, as most of you know. The weakest point in the stock k-series bottom end is the rods/pistons. The rods are the typical i-beam cast rods that are perfect for N/A applications, but not good for ultra high revs and boost.

It's very important to understand that all these things make the k20a2 such a great engine. The head may flow a little better than the evo's 4G63 head(intake flows more and the exhaust is a little less), but that only tells about an 8th of the story. Like i have said before, you have to take into account all the other factors involved, like combustion chamber design, valve and valve seat design, piston design..ect. Just the crank alone is worth a lot as the crank alone is worth a lot more power. It's a extremely well engineered engine and if it were meant for a turbocharged application, the pistons and rods would have been upgraded from the OEM, this would literally make the k20 perfect in just about every way, in stock form.

Now, even with just a simple swap to forged pistons, @9.5:1 static CR and a good set of h-beam billet rods and a set of headstuds and OEM head gasket...and you have an engine that can handle 600+whp with simple bolt ons(even the stock sleeves are good for this power, although sleeving is deff recommended at these power levels). It's not only a well designed engine, it can make very cheap power, even on stock cams(really long duration of the stock cams= more cam overlap which is bad for boosted engines)!

I see the 4G63 needs soo much to make lots of power, even with a lower static CR.(of course, read my ealier post in regards to static and effective CR's)....a cam change is needed right off the bat, it can't handle too much boost on pump gas.....and is kind of watered down in stock form.... You can make a ishload of power, but you have to spend a lot of money building the bottom end getting it preped for the supporting bolt on mods that are obviously needed to make big power. With a k20, just swap pistons/rods(obviously this is the super cheap way, but still makes a lot of power very safely with a good tune)......bolt on the turbo/mani of your choice and tune away.

It's important for you to know that i have both of these engines. I love my EVO for the chassis and drivetrain.....i don't really care for the engine at all. I have a turboed RSX-S for it's engine and engineering.....although the chassis is not bad, the fact that it's FWD is it's lacking point.

back to the heads of these monsters: just because you flow more CFM's does not mean you will make more power, it's all about keeping velocity% of the port as close to 100% as possible. A head that flows 240cfm@28" @400" lift at 90% port velocity will make more power than a head that flows only 270cfm@28" @400" lift at 70% port velocity. This even applies to forced induction set-ups, although not as much, but does apply for sure.

There are just too many variables and very few constants to sum everything up about these two engines without getting really deep and long winded.....But for my money and my knowledge my opinion is the K20A(2)(Z1) is the best 4 cylinder made, by anybody at any time...ever. Don't think that i am taking anything away from the 4G63.....it's a close second for sure, even though it's technolgy is somewhat archaic in certain terms.


CJ

dan l

iTrader: (3)

6 bolt 4g63 = fastest 4 cylinder in the world. You and the whole world can put a K20 up to the 4g63 but so far, it isn't enough.