2139 replies to this topic

[The Batman]

P.s who wants to buy my key ring tape measurer?

[Rosssco]

Isn't the K20A a 'productionised' version of the S2000 F20C motor?

 

If so, what differences are there between them that allows ~240bhp vs. ~200bhp?

[The Batman]

Not sure what the differences are bud The new manifold is going to need a bit of modding for the water ways

[The Batman]

Project cylinder head just got delivered

[Aerodynamic]

The K uses VTC and the F doesn´t.

The F is much more tuned, with some candy I consider the K ´to be just as good.

[FLD]

Project cylinder head just got delivered

So you can take pictures of packaging

[The Batman]

It was oily and would be a death wish to open it up on the new table

[JimmyJamJerusalem]

ooh that really is nice Joseph!!

[Arno]

Isn't the K20A a 'productionised' version of the S2000 F20C motor?

 

No. The F20C is design-wise more like an intermediate engine between the previous D-, B- and H-series engines and the later K-series.

 

The F20C lacks the cam-timing adjustment (VTC) and only has the profile switch (VTEC) which is the cause for it's less-than-stellar torque at lower rpm's.

 

In this respect it's more like the B/H-series engines, but it does rotate clockwise (older Honda engines ran were counter-clockwise) and the block and head design follow the same general design as the later K series engines. Various parts are interchangeable between the K and F series with sometimes some minor modding. Various K-series parts are often used by S2000 owners to improve the engine.  

If so, what differences are there between them that allows ~240bhp vs. ~200bhp?

Revs

 

Heads are fairly similar when it comes to shapes of chambers and ports/channels.  OEM Intake manifold on the F20C is actually not that great.

 

However.. The F20C is a slightly larger bore and shorter stroke (87x84mm) than the K20 (86x86mm) so it allows the F20C to safely run up to 9200rpm in stock form.

 

As BHP is simply a function of revs+torque, as the revs rise and you can keep the torque at a reasonable level then the result is a higher peak HP. F20C also came with a good/long exhaust manifold and decent exhaust routing. K20A standard enxhaust manifold is pretty short/compromised in comparison.

 

Also, the K20A2 in europe and the US was limited to 7800 rpm and rated at 197HP while the Japanese K20A ran 8600rpm and around 225 Bhp in stock form.

 

Not really sure why as the're very little, if any, construction difference between the K20A and K20A2 apart from some minor detals like slightly higher compression (11.5:1 vs. 10.5:1) and a tad wilder cams on the JDM K20A. Probably an emission/marketing/something reason

 

It's not too hard to make the K20A2 generate between 220-240HP in N/A form with good intakes and exhaust setups combined with a little more agresisve cams.

 

Also it's a very different experience drving a K20 compared to an F20C as with a Hondata equipped OEM ECU (or a standalone ECU) you can map and set up a K20 to have a load-dependent VTEC switchover which, combined with the VTC cam angle adjustments, makes it a virtually seamless switch to the 'wild' cam profile and no longer the 'VTEC yo!' *bump* of the older engines. This makes the power band very wide and it pulls smooth from idle al the way to the rev limiter.

 

Bye, Arno.

[The Batman]

Thanks for the info dude

Tb and rrc adaptor plate turnt up today



I want to get the inlet and outlet bored out. Will any machine shop so this for me?

Also my jdm cams turnt up



So all phase 1 parts are in

[Rosssco]

 

Bye, Arno.

 

 

Good answer (as usual)..

 

 

[Arno]

Thanks for the info dude

Tb and rrc adaptor plate turnt up today

TB seems a little incomplete? Missing the TPS at the side and idle control valve at the bottom. Also still seems to have the second cable wheel for cruise-control on it. (probably not from an EP3 typeR?)
 

I want to get the inlet and outlet bored out. Will any machine shop so this for me?

Decent machine-shop should be able to help you.

OEM TB's can't be bored out too much as there isn't very much 'meat' in some parts.Usually the butterfly can be brought to 64mm and the housing tapered from the ends starting at 70mm.

RRC manifold should be no problem to bore the intake connection to 70mm. Little or no channels in it.

I see your RRC is not modified for the older engine style yet (K20A). Usually the water outlet connection that's integrated in the flange on these (for the later K20Z engines) needs to be cut off for the older engines as they have a separate outlet spout attachment and not integrated in the manifold.

Bye, Arno.

[Mangham54]

Arno... Your knowledge of pretty much everything just astounds me. Keep it up ::

[Nev]

Don't forget to drive it Joe! How many miles have you done so far? If ever come near Bristol give me a PM/ring and I'll show you what Vauxhall turbo power can do these days, you may sell your "imposter" and swap back to a VXT

[Scuffers]

Guy in my area runs a K24 with 357 bhp N/A...... Sounds like a motorbike and runs like a beast. Should be awesome in a VX!

No idea how long it'll last...

 

with respect, that's total fiction (assuming it's running on petrol), head/87mm bore just can't flow that much, period.

 

Isn't the K20A a 'productionised' version of the S2000 F20C motor?

 

If so, what differences are there between them that allows ~240bhp vs. ~200bhp?

No, as Arno said, different generation of engine.

 

F20C has 'better' head port design (all 100% symmetrical etc), but lacks VTC, and because of the port design, it's more bulky.

 

Power wise, F20C can make more power in std trim, but it's only in the last ~800 Rpm, K20A is all over it up to that point.

[TFD]

 

Guy in my area runs a K24 with 357 bhp N/A...... Sounds like a motorbike and runs like a beast. Should be awesome in a VX!

No idea how long it'll last...

 

with respect, that's total fiction (assuming it's running on petrol), head/87mm bore just can't flow that much, period.

 

 

No worries mate, it's not my car nor am I really connected with these guys. All I know is they spend shitloads on Honda stuff and make serious N/A power. Previous engine did 297 bhp but ended up in pieces. He build a new one and pushed 357 bhp. Car is not roadlegal anymore I've heard. Check out their facebook site for more info "0118 racing"

 

https://www.facebook...8racing?fref=ts

 

Grtz,

[Scuffers]

Appreciate that, 

 

it's simply not credible though, 357 HP at the crank would require a K24 at 8,000Rpm running some 135+% VE

 

that is simply not credible, the very best NA race engines might approach ~110-115% VE (and by best I mean purpose designed stuff, not re-worked production)

 

to get to 135% you're usually looking at forced induction in the 10-11+Psi boost range.

 

(I await the inevitable dyno plot!)

[Aerodynamic]

Appreciate that, 

 

it's simply not credible though, 357 HP at the crank would require a K24 at 8,000Rpm running some 135+% VE

 

that is simply not credible, the very best NA race engines might approach ~110-115% VE (and by best I mean purpose designed stuff, not re-worked production)

 

to get to 135% you're usually looking at forced induction in the 10-11+Psi boost range.

 

(I await the inevitable dyno plot!)

Well a friend of mine in the Swedish Hondaclub is not havig 357 bhp but a respectible 331 bhp NA and this with std port size and OEM RRC manifold. A  full CNC head bigger valves and a Skunk 2 Ultra manifold with spacer or any other good  manifold. And those numbers shouldn´t be too far away. This is on E85.  + There are more candy you could bring on.

 

http://rejsa.nu/foru...r=asc&start=294

 

BR, Per

[Scuffers]

Well a friend of mine in the Swedish Hondaclub is not havig 357 bhp but a respectible 331 bhp NA and this with std port size and OEM RRC manifold. A  full CNC head bigger valves and a Skunk 2 Ultra manifold with spacer or any other good  manifold. And those numbers shouldn´t be too far away. This is on E85.  + There are more candy you could bring on.

 

http://rejsa.nu/foru...r=asc&start=294

 

BR, Per

 

Also not very credible, although he is running E85 not petrol.

 

8,000+ Rpm on a 99mm stroke is also pretty risky, (piston speeds exceeding that of the old V8's in F1 doing 20K+ Rpm)

 

I can believe he's at ~300hp levels, maybe a tad more, and to be fair, his torque figures look reasonable realistic, my guess is the dyno's being unrealistic higher up the rev range.

 

 

 

 

[Nev]

NA power from 4 pots is hard to win. I wonder if anyone will have the balls to try and fit a V6 transversely into a VX one day...