raverx3m

iTrader: (1)

everyone says the k series more power over b series.
then they jump to comparing a 1.8 liter b series to 2 liter or even 2.4 liter k swaps

but it seems like a 2 liter stock type-r motor with boltons would be very similar power to a 2 liter k series type-r with boltons both tuned.

any shops here have some unbiased opinions or maybe even dynos or both.. im just curious
I know all about the advantages of the k series. but I want to see on dyno sheets..

or even better if any shop has a dyno of a b series with same compression similar cams and intake manifold and boltons to k series.

2LEM1

iTrader: (1)

Calvin (blackdc4) had a built B series and a built K series dyno'd on the same dyno. I think the K was a 2.4liter though.

Don't quote me, but if I'm not mistaken the K made like 280whp, but his B series made like 275 on race gas. IDK, probably best if he chimes in.

raverx3m

iTrader: (1)

well stock b18c makes 200hp
11.1 cr
not sure about how b and k R cams compare to eachother

stock k20 makes 215
higher compression taller deck
roller rockers
besides the head design differences obviously
but it seems to me they both are maybe within 5whp from eachother when built with same exact specs

2LEM1

iTrader: (1)

I'd love to see a 2.0 K motor making over 250whp. I'm sure they're out there, I just don't know if I've seen it. Most are in the 235 range.

GEN2 LS

iTrader: (3)

This is my stock longblock k20a2

RRC intake manifold/w stock TB
Karcepts CAI with V stack
Ebay header 2.5in collector
3in exhaust
Tuned on Kpro V1 on 93 pump gas

plenty of built b20vtecs Around my area making the same if not more but they're running RS Machine pistons and aftermarket cams.

I think 250whp out of a stock K20A2 should be easy with cams. My vote goes to 2.0L K. 2.0L B won't match the K for torque regardless.

UncleD

iTrader: (2)

Wut.

ChrisCoupe1

the K with its more modern and factory optimized valve train and heads should always have a HP advantage and torque when you have a general apples to apples Mod for Mod comparison between the TypeR K20 and a Type R B18C/B20 setup, but besides the differences in power made due to displacement and effective Compression ratio from factory(K20R 11-11.5:1 vs the 10.6-11:1 B18CR) theres also the fact that the K20 runs a Square BorexStroke vs the Long Stroke of the B Series. So from what I've read and seen a square bore vs.stroke allows for greater torque at a lower RPM and a more linear curve at lower total RPM vs a more peaky/high rpm curve for the long stroke.. Any built B series I've ever seen have all run a Long stroke setup due to the inherent design of the Engine. But say with some crafty tuning and K20 2.0 build to 2.0 B series build you had both motors produce the same PEAK HP and PEAK Tq figures they would still be vastly different in the way that power comes on and at what RPM.
As far as advantages go the K20 can gain power with less overall work(basic bolt on's and tuning) then a B but at a higher price all the way around where a B could be built(pistons/rods/cams/valvetrain/ head work) for the same or significantly less money then a base K setupm which the B Could produce equal or more power Until you move to real high power race style territory where the more modern K really Shines

raverx3m

iTrader: (1)

what b series cams wouls stock jdm k20 R cams compare to?

raverx3m

iTrader: (1)

chris. the sleeved itr wouldnt be that far away its 85x87mm vs 86x86mm
I see a lot of stock k20a motors produce between 210-225whp when tuned. and around 150-160 tq

but obvious problem is finding a 2 liter type-r build with stock cams lol or even bc3 or other itr like cams..


im just not convinced that k motor is THAT far away from b series when all things being equal...

1HGEJ2

iTrader: (1)

dont forget k20 intake and exhaust valves are bigger (2mm on each side) so u get more in and out.

whitesihatch

^^this.

For most 2.0 b series with comparable to k series (meaning near c/r and fuel types) The k series make a bit more torque.

PyroProblem

Im kinda with you on this... 2 liter K series vs 2 liter B series will make about the same power and torque.
A maxxed out 2L should make about the same as any other "maxxed out" 2 liter.
It comes to a point where 2 liters of displacement can only make so much power on a certain type of fuel. Even with custom everything, 2 liters can only ingest so much air without force..

Will the K make more power? Probably, but only due to the several minor improvements to its predecessor... My 2 cents.

blacK_Dc4

- a stock K20R with bolt-ons and Kpro usually hit 225-235hp on our dyno.

- a 2L B doesnt always need sleeves or forged pistons. all it really needs is 11.5:1 compression which is similar to a stock K20R

the head will generally require a portjob (to be more efficient like the K20R), and some sort of stage 2 cams. Then you can throw on similar bolt-ons like the ones made for the K20R .... and use a system such as the S300 (Similar to Kpro) and now you can finally reach 225hp-235hp.

what i am trying to show is what you need to do on a 2L B to "catch up" to a stock K20R.... as far as having a tuning sytem, compression, headflow, and bolt-ons.

now that we have both the K20R and 2L B making the same 225hp-235hp range, i can tell you that the powerband will look very different. It will probably destroy the B from 4K-7K (midrange) and both will top off at around 8500rpm....(well the B may get up to 8700-9000)....

in the end, those are the differences if you are wondering why a 230hp K is faster than a 230hp B. Its a whole other discussion if you want to talk about how far a 2.0L K can be pushed vs a 2.0L B

raverx3m

iTrader: (1)

anyone got some dynos? im interested
just cant find any good comparisons. they are all from different shops...

2LEM1

iTrader: (1)

Calvin do you have an overlay of the B and K motors?

slowsleeper

Calvin pretty much summed it up!

ojasia

Thnx. For the info! Good read.

PSI GUY

iTrader: (2)

Well, our engine is a 85x89 B18C, 13.5-13.8 compression, 4Piston CNC head, ported VictorX, good header, cams and made 260. Just did a K20/K24 setup, 12.5:1 pistons, stock head and intake with tuner 3s and it made 265. The K series has way more potential to make power, just wish they were a bit more reliable and could take the abuse that the B-series do.

2LEM1

iTrader: (1)

Yeah that's a pretty serious build.

B20VtecVillain

I would definately agree with what has been said so far; as far as peak #'s all things being equal a 2L B and 2L K can both achieve about the same figures with the K possibly beating out the B slightly on torque due to advancements in technology and whatnot that went into the new K series design. That being said though, the K will almost always produce a more useable powerband and area under the curve and will therefore be faster than a comparable B. A good example would be my VTEC headed B20 EM1 before I went boost and my cousins K20z1 swapped EM2 coupe. At the time I was at stock 84mm bore but ~12.5:1 compression, SK2 Pro 1s, ported ITR intake manifold, ported B16 head w/Supertech VT components, PLM header, 3" Thermal exhaust (catless) AEM V2 intake, RC 370s and tuned on S300 it made like 230hp/165tq.
He was a stock shortblock K20z1 with K20a cams, Custom swap header, 3" mandrel exhaust with Magnaflow cat and race muffler, 3.5" intake w/Vstack and tuned on Flashpro he made like 10hp less than me but the same TQ. We were both about the same weight and even though he had a slight power disadvantage he could still pull ahead about a car length on me every time we ran our cars and I couldn't quite fill the gap. His power just always came on quicker.

PSI GUY

iTrader: (2)

But wait......there's more coming....lol.

raverx3m

iTrader: (1)

so if I plan to beat on it I should still buil da b series?
cuz I plan to beat on it lol

PyroProblem

I think the Ks better power band comes from the variable intake timing. Many cars do this to increase lower rpm torque.
If I had the extra $, I would build a 2.6 L k series. Not too many B series making 400+whp.
Until then, B series all the way.

raverx3m

iTrader: (1)

how are you gonna daily a 400whp k swap car? were not talking about all out drag racing here

its obvious not too many b series make that power because of the displacement limit.
but I think they make about same power once they step into that field. k series wins because it allows for more displacement.
since theres no more VVT when you have a 300-up WHP drag car

PyroProblem

I never said I would daily a 400 whp 2.6 k series.
If I was doing a daily driver, I would be keeping a.c. and maybe PS which means no K series in a vehicle that didnt come with one from the factory.