RSX type S head

[Dres97]

Hey anyone read the new Super Street where it had the Stage 2 part of the Skunk2 Civic Si. They said they swapped the head and they were getting with a CAI hondata and the head and headers 40 more HP? Cause they Dyno the car at 133 and they said they ended up with those mods at 171 to the wheels... so my question is did they just buy the head and headers of a type S and swap it or what?:o

[myeverlovinsir]

I have not read that article, but know of others who have done the
head swap. They found that they also needed to do the piston
swap to get the RSX-S gains. Not sure what they did there, but
171whp sounds like they upped the compression as well. hmmm

Edit: I now have this done. 170whp is a reality with the stock compression (9.8:1) Check my sigi link:D

[2k2ep]

you can use a gasket for a little more compression

[USMCSI]

I'm pretty sure that they used the stock pistons in that article. Possibly a gasket although they didn't say..

I think that this is better news for anyone going turbo, as that would be a cost effective base for a more powerful motor.

[!@#$%]

okay i went and bought this so I could clarify this thread.

In the pic where the head is off, the Si pistons are in. I don't think they used the type s pistons.

They don't even say anything about needing an rsx-s ecu. Maybe our ecu has the 3rd lobe vtec encrypted but has nothing (cam wise) for it to engage.....*shrugs Maybe Hondata changed something in the stock si ecu to make the VTEC work at 5800 or whatever it goes at. Hopefully Doug will see this thread and give us some more info. Hell, he is in the pics too. I'm also wondering if they used stock dc5 cams. It says nothing about them switching the cams either! This is either too good to be true, or too damn incomplete.

They used a stock head gasket I assume. They said absolutely nothing about it.

The downpipe to the cat has a larger diameter than the si one, so they swapped that which forced them to do a little welding.


I have a few questions for everyone to ponder and maybe something doug can answer. (if he still frequents the board)

If the rsx-s head was swapped onto an k20a3, would operation be the same as say doing a k20a2 complete swap? Does the car go haywire after 5800?

Can the stock k20a3 cams be run in the rsx-s head? Obviously the a2 cams don't work in the a3, but since the a2 head has placement for 3 roller rockers, could the a3 cams work without actually engaging vtec? If so, that would mean any one of us could buy the rsx-s head, throw in our stock cams, and basically have a better flowing head, still without vtec, and no [stock] ecu problems until we can get some better cams. (for us poor people who have to do things in steps :( )

Jesus we need more information on this damn article. I'm inclined to call skunk2 right now and ask them while I try and get a silencer for my exhaust. :angel:

also we can get a brand new type s head from acura for $1321.61 if some of the things I said are true, then I might just be buying one by august.

[dc5-K20A3]

If the rsx-s head was swapped onto an k20a3, would operation be the same as say doing a k20a2 complete swap? Does the car go haywire after 5800?

The RSX cams are included in the K20A2 head.

[B18CXr]

PRB cams will NOT work in a PNL or PNA head.

EP ECU will run a PRB head just fine....

:beer:

[!@#$%]

Originally posted by B18CXr
PRB cams will NOT work in a PNL or PNA head.

EP ECU will run a PRB head just fine....

:beer:

so you are saying the EP ecu will work with the rsx-s head? Are there any sensors the PRB head has that the PNL head doesn't? What about the oil cooler on the k20a2....would that hurt the a3 in any way by not having it? :confused:

[Dres97]

all right i thought i knew about cams but guess not what are these different type of cams is it just the stock names of honda cams or are they type of cams?
:o

[Jodster]

So your saying that the K20A2 head bolted on to the A3 block works just fine with the A3 ECU? Then add I/H/E and hondadata, and you get 171whp? Thats not impressive to me. People here are getting 160whp with I/H/E and hondadata. So after that, spending $1300 for the A2 head you will only get 11 whp more? Not worth the money to me.

But if you put the A2 head on the A3 block would you be able to use the A2 ECU? Would the stock A3 block be able to handle the 8200 rpm redline?

[myeverlovinsir]

Originally posted by Jodster
So your saying that the K20A2 head bolted on to the A3 block works just fine with the A3 ECU? Then add I/H/E and hondadata, and you get 171whp? Thats not impressive to me. People here are getting 160whp with I/H/E and hondadata. So after that, spending $1300 for the A2 head you will only get 11 whp more? Not worth the money to me.

But if you put the A2 head on the A3 block would you be able to use the A2 ECU? Would the stock A3 block be able to handle the 8200 rpm redline?

First off no one is getting 160whp on a dynojet dyno. Only on
dynopack! We all know that's a 10hp differential to begin with.

Second of all 171 whp with a head swap does require a hondata
flash (rsx-s ECU), more money. The head is not going to work
without the proper ECU, don't kid youself.

Third the best you can expect from hondata and I/H/E on a dynojet
is 155whp at the revlimter, which I have proven. This is a false positive.
The reason I say that has been covered here. When you hit the rev-limiter
on the dyno you experience a small spike, that is not condusive of
a true power amount. Realistically the best you could expect is
near 150whp with those basic mods.

Fourth, the head mod giving a reading of 171whp, was it on a
dynojet? If so, then I think the 20wph gain is about right.

I would recommend getting the compression up if you want to
go beyond those numbers. Some have responded saying that
they are not sure if a head gasket was used, regardless, I would
swap out the pistons as well, if you intend to stay NA, otherwise
your a boost away from a real gain. gluk!:)

[siver-SI]

Ok just a quick question about reading about the A2 and A3 before. To get the 8200 rpm redline would you not have the change the crank too? I though that A2 had a better ballance then are A3 and that is why they had a higher redline for one thing.

When I add a supercharger I am going to pull the engine to beef up the engine a little but if I could use some A3 parts that would be great. Or I guess I could look for a A2 out of a junk yard. I think they will be hard to find up by me. I would love to get a 6 speed in my car too with that Supercharger.

[myeverlovinsir]

Ok just a quick question about reading about the A2 and A3 before. To get the 8200 rpm redline would you not have the change the crank too? I though that A2 had a better ballance then are A3 and that is why they had a higher redline for one thing.

I would not worry about the rpms with which you can rev the A3.
I have been told and others have tested the A3 to over 10k rpms
safely (hondata has played with this). The A2 crank may be balanced better, but time will tell.
8200 rpms on the A3 is chump change. I have reved it on the
dyno and on the street too many times to be concerned.

The one thing that is clear is that not only are the pistons
shorter in the A3, but the rods are less beefier on the A3. I think
this is the only downfall when it comes to reving past 8k for
extended periods. The crank does not seem to be the major issue. hth;)

[siver-SI]

So for me a supercharger with some beefed up pistons, rods, and a A3 head would do nicely then I guess. I bet that would be cheaper then trying to pull a A2 out of a bone yard. I have been tring to figrue out this future mod little by little. I want to have a supercharger but good engine life too. I knew at least I was going to have to upgrade the piston rings for blow by.

BTW what is are crank made of? Cast Iron?

[myeverlovinsir]

I am gonna throw the SC on with the stock pistons and rods.
It can handle quite a bit in revs. The problem occurs with how
much boost. 4.7lbs in the basic SC seutp vs. the 10-12lbs boost
in the upgrade may be a little more risky. I would do what you
said...upgrade the internals to handle the boost it you want
the higher boost upgrade. Personally I will beat the shit out
of the stock components with the SC base before I upgrade the internals. But that's just me. Others will opt for the high boost
or make the custom mods (pulley) to get higher boost on the
stock internals. Don't forget that with the upgrade you also
need the Hondata flash and larger (RSX-S injectors) to get the
benifit of the tune and boost levels. hth :p


crank is made of the same shit as the type-r only not as balanced.
Not sure if it's cast, but think that it is.

[fsugatorbait]

So to sum it up...all we need is the A2 head and ECU? That would run our redline to 8200 and our internals would be fine, correct?

EDIT:would the A3 ECU run the A2 head? with the understanding that it wouldnt nearly come close to the full benefit of the mod.

[c0mf0rt]

No kidding.... no one has answered that yet... I read the same article in Super Street and it mentions NOTHING about swapping the ECU..... I just don't understand how if the Cams are different.... how the A3 ECU would function properly with an A2 Head...... So does anyone know for sure???? ECU swap????

[S800Racer]

Originally posted by c0mf0rt
No kidding.... no one has answered that yet... I read the same article in Super Street and it mentions NOTHING about swapping the ECU..... I just don't understand how if the Cams are different.... how the A3 ECU would function properly with an A2 Head...... So does anyone know for sure???? ECU swap????

Yes, I know for sure. Jack Harris at P1auto already answered this without going into detail. He has an EP with K24 block and A2 head still running the A3 ECU. His dyno charts show the power increase at 2200 rpm where the vtec switches over. I drove the car. It runs just like an ordinary EP (only faster!) with the same 6800rpm fuel cut-off.

[c0mf0rt]

Thankyou GOD.... the answer has finally been given.... one last thing... is that an A2 head with A2 cams??? or A3 cams???

[fsugatorbait]

Originally posted by c0mf0rt
Thankyou GOD.... the answer has finally been given.... one last thing... is that an A2 head with A2 cams??? or A3 cams???

It has to be A2 cams...wouldnt make sense to swap to the A2 head and then swap out its cams for ours.

[02-sir]

Originally posted by c0mf0rt
No kidding.... no one has answered that yet... I read the same article in Super Street and it mentions NOTHING about swapping the ECU..... I just don't understand how if the Cams are different.... how the A3 ECU would function properly with an A2 Head...... So does anyone know for sure???? ECU swap????

the car in the mag had Hondata, so it was no longer an A3 ECU. Hondata can take either an A3 or A2 ECU and flash it with their RSX-S flash, at which point the two ECU's would be the same.


hth

Nick

[myeverlovinsir]

Originally posted by 02-sir


the car in the mag had Hondata, so it was no longer an A3 ECU. Hondata can take either an A3 or A2 ECU and flash it with their RSX-S flash, at which point the two ECU's would be the same.


hth

Nick

Exactly. The ECU will have to be flashed if it's from an A3 in
order to work in with the A2 head properly. You cannot expect it to
suddenly know when to engage the large cam lobes. Hondata
also would have made adjustments to the timing/fuel maps and
rev-limit as well. As was mentioned previously with the K24 block
and A2 head and A3 ECU, sure it may work, but why would you
want to put the A2 head on only to have it hindered of it's potential
by the A3 ECU?

[02-sir]

Originally posted by myeverlovinsir


Exactly. The ECU will have to be flashed if it's from an A3 in
order to work in with the A2 head properly. You cannot expect it to
suddenly know when to engage the large cam lobes. Hondata
also would have made adjustments to the timing/fuel maps and
rev-limit as well. As was mentioned previously with the K24 block
and A2 head and A3 ECU, sure it may work, but why would you
want to put the A2 head on only to have it hindered of it's potential
by the A2 ECU?

yup, I agree. I don't want to knock Jack (B18CXr) because he's putting a lot of good R&D into the K series, and is kind enough to share the results (somewhat). However, I don't think he will ever be able to extract the full potential of the A2 head without an ECU that's specifically tuned for it. Even if he can control the fuel perfectly with piggyback devices, the cam timing will still be off.

just my $.02

(again Jack, no offense, I appreciate the work and info you share with us)

[S800Racer]

Originally posted by 02-sir


yup, I agree. I don't want to knock Jack (B18CXr) because he's putting a lot of good R&D into the K series, and is kind enough to share the results (somewhat). However, I don't think he will ever be able to extract the full potential of the A2 head without an ECU that's specifically tuned for it. Even if he can control the fuel perfectly with piggyback devices, the cam timing will still be off.


Don't worry, his plans for that motor include an A2 ECU and a turbo.:D

[02-sir]

Nice! Can't wait!:p

[B18CXr]

so you are saying the EP ecu will work with the rsx-s head? Are there any sensors the PRB head has that the PNL head doesn't? What about the oil cooler on the k20a2....would that hurt the a3 in any way by not having it?

I'm running the oil cooler on the K24, around $350ish new from dealer(all hoses and clamps)

[B18CXr]

yup, I agree. I don't want to knock Jack (B18CXr) because he's putting a lot of good R&D into the K series, and is kind enough to share the results (somewhat). However, I don't think he will ever be able to extract the full potential of the A2 head without an ECU that's specifically tuned for it. Even if he can control the fuel perfectly with piggyback devices, the cam timing will still be off.


you are correct....higher redline is a must on my kar, but until a stand alone comes about, I'll just standby


:)

[02-sir]

Originally posted by B18CXr

until a stand alone comes about, I'll just standby


:) [/B]


that would be awesome. good luck and keep us updated!

[cbecker333]

Originally posted by S800Racer


Yes, I know for sure. Jack Harris at P1auto already answered this without going into detail. He has an EP with K24 block and A2 head still running the A3 ECU. His dyno charts show the power increase at 2200 rpm where the vtec switches over. I drove the car. It runs just like an ordinary EP (only faster!) with the same 6800rpm fuel cut-off.

So...does that mean he's running on the A2s high-lift cam lobes from 2200-6800? Or does the engine not use the high lift lobes at all? I'm trying to figure out what an A2 head does that correlates to the 12-16 valve 2200rpm switchover on the A3? Am I going nuts?

[S800Racer]

Originally posted by cbecker333


So...does that mean he's running on the A2s high-lift cam lobes from 2200-6800? Or does the engine not use the high lift lobes at all? I'm trying to figure out what an A2 head does that correlates to the 12-16 valve 2200rpm switchover on the A3? Am I going nuts?

If I understand vtec operation correctly, there is a preset rpm where the vtec is activated. There is no real difference between A2 and A3 in the how the mechanism activates. Take a good look at the mechanism in the A3 - the vtec locks both intakes to the "normal" cam lobe at 2200rpm in the same way that vtec locks the intakes (and exhaust?) to a high lift cam lobe at high rpm.
So I think the answer to your question is yes, the A2 head is operating on it's high lift cams from 2200 to 6800 rpm.

[soniccar]

That's reasonable. Does the Controller now adjust the vtc pulley on the exhaust to the same increment as the intake cam or does it not operate? I though the VTEC switchover was higher on the RSX, which always runs in 4 valve mode, kinda like the B16 DOHC motors.

The Si crank is forged, by the way.

[SHAKEnBAKE]

Originally posted by soniccar

The Si crank is forged, by the way.

No shit? I always thought it was cast.:eek:

[siver-SI]

I know this is dumb but wanting to make sure the forged is better then cast right. I think it sould be lighter if I remember my bottom ends right. Man i have not torn down a engine in a few years I realy need to take an extra engine I have laying around and work on it for fun.

[02-sir]

Originally posted by soniccar
That's reasonable. Does the Controller now adjust the vtc pulley on the exhaust to the same increment as the intake cam or does it not operate? I though the VTEC switchover was higher on the RSX, which always runs in 4 valve mode, kinda like the B16 DOHC motors.

The Si crank is forged, by the way.

the vtc pulley is similar for both A2 and A3 heads, intake only.

[Vertigo]

you are correct....higher redline is a must on my kar, but until a stand alone comes about, I'll just standby


:) [/B][/QUOTE]

Jack (B18CXr). If you do raise the rev-limit to 8200, and because you are running a 2.4 short block. With the longer stroke and reving it to 8200 rpm the piston speed would be around 5100 feet per min. Without a seriously beefed up bottom-end all i can say is.. DUCK! Even the hi reving F20C1 S2000 motor at it's 9000 rpm. The piston speed is around 4900 fpm. But I'm sure you have allready taken this into consideration.

[excivic98]

I am planning on doing the head swap and hondata flash, I have a couple of questions though. In the Super Street article they said that the exhaust needs to be shortened because of the rsx manifold and cat, my question is since I have a Buddy Club Cat-Back does that mean that I can take out the extension I had made and the exhaust will bolt right up to the rsx cat. Thanks

[Vertigo]

Are you saying that you have a flex joint between the cat and the b-pipe? From what i saw in the article if you use the RSX-S downpipe (cat.), then you will have to shorten the b-pipe in order for it to work. Does anyone know if the collector diameter on the type-s manifold is larger than the stock A3 manifold?

[chet]

I have been considering this swap and I wanted to let you guys know I emailed Skunk2 about it. BUT, the only thing that was in the reply. . ."I believe you need the head, ecu and exhuast manifold." I started another thread about the same subject, didn't know this one was here.

Anyway the email seems pretty vague, don't you think?:(

[excivic98]

I had to have a peice of piping welded in between the cat and the b pipe to make the Buddy Club exhaust fit properly since it is made for a Type R not an SI. What I was asking was if I use the RSX downpipe can I remove the welded in peice.

[soniccar]

I'm sorry I zoned out. I thought someone posted a picture of the A2 head and the A3 head. The A3 head only had the VTC pulley on the intake and the A2 head had both. See?

Forged cranks are better since they are deformed and worked (cold or hot) so to remove internal voids and "compress" or align the internal grain structure so that the yield stresses it can endure are higher (stress before permanent deformation results). Also, elongating the grain structure prevents a crack plain from propigating across a grain boundary. Cast, you don't know what you have as far as internal defects go, and it will not have been deformed so as to "balance" the piece. Additionally, with the short grain structure and relatively round grain, crack plains can propigate quickly making a cast piece fatigue much quicker and castistrophically. A forged bar will be diffcult to fail when cracked but a cast one will fail very quickly and unpredictably when cracked.

[siver-SI]

Ok I have to act dumb now. What pulley are you talking about? I just do not see it sorry. I have to take off my valve cover one time on this car for the hell of it to see what this top end it like.

[TravisEP3]

The only difference I can see is the part that is circled. :o Hope this is it.

P.S. - I dont know what I'm talking about and just am trying to help by pointing out the differences that I see. :)

[Vertigo]

I think that Soniccar was talking about the cam gear. On the a2 head, it has the VTC pulley on both cams. Were as on the a3 head only the intake cam has the VTC. The circles that TravisEP3 made are showing how the a2 head has the vtec cam lobs on the exhaust cam. Also, how the a3 exhaust cam lobs do not.

[02-sir]

that's interesting, I could have sworn I read somewhere that the variable pulley was on intake only for both A2 and A3. But I do agree that it looks like it's on both cams for the A2 head. Anybody with a helms manual for the RSX care to post some concrete info?

thanks.

edit: I just found this on clubrsx. I'm pretty sure vtc is on the intake only. (shawn Church sets the record straight half way down)


clicky clicky (http://forums.clubrsx.com/showthread.php?s=&threadid=59162&perpage=25&highlight=vtc%20exhaust&pagenumber=1)

[Vertigo]

Well, I guess i stuck my foot in my mouth:confused: I was just guessin to. But i figured since the a2 has the real version of VTEC (the one we use to love), both of the cam pulleys would have VTC. Ya can't win um all. :angel:

[siver-SI]

OK I see now. Sorry not good with import heads yet. I am still use to V8 GM and Ford blocks and heads. I still have a lot to learn about import engines though. Just wondering anyone know were I can find some good reading about Honda Engines?

[Vertigo]

Silver-SI, i know where you are coming from. I've been around V8's all my life. My dad builds the engines for my cousin's late model stock car. About the reading material. I bought the Honda builders handbook by Joe Pettit at Books-a-Million. It was published back in 96, so it's kinda old school. But it explains(in detail) the popular B-series and the D-series Honda engines. It gives you a real insight into honda engines

[02SilverSiHB]

wow, I think I'm learning something here :D I've never really understood much about the internals of the engine...I'm glad we have this post...good one! :D

[myeverlovinsir]

Just to sum up and clarify. The A2 head has VTC (+/- 25deg) on the intake cams only, look on the left of the pics. These are hydraulically controlled mechs.
Intake/exhaust lobes are also clearly diff. One lobe on the A3 exhaust
and 2 lobes on the intake. A2 has 3 lobes per side.

Vtec engagement on the A2 engages @ 5800rpm stock, A3 @ 2200 rpm.

The

[02SilverSiHB]

It looks like I'm going to just save my money and get a DC5R motor. And if I really want boost then...I'll just build it to handle the boost.

[KickerSi]

Okay, I'm really confused! I need to know a few things. One, Is there any special fabrication needed to get the A2 head to fit our block like you need to do with Ls/Vtec? 2nd, I will most likely use the stock ecu for now, when I get the type-s ecu, will Vtec kick in on the exhaust cam or will using the stock ecu mess something up? Lastly, why do you need to use a piggy back fuel system with stock ecu, and what would you use? Will a Apexi AFC do the trick? Any info would be great.
Thanks

[B18CXr]

WHAT THE PHUCK!!!!!??????

How did this post get sooooo far off track?

First off, ALL K SERIES MOTORS HAVE VARIABLE CAM TIMING ON THE INTAKE ONLY!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ONLY!!!!!!!

The exhaust gear is NON ADJUSTABLE!!!


CRV/Accord/Element and K20A3 motors only have Vtec on the intake side

TSX and K20A/K20A2 have "real" Vtec on both cams


The attached pics are mine from months ago, so if you have any question, please ask.


Trust me....

--------------------------------------------------------------

Yep, I know that. She' seen 8100 already but surely will not last long if sustained for hours on a road course



Jack (B18CXr). If you do raise the rev-limit to 8200, and because you are running a 2.4 short block. With the longer stroke and reving it to 8200 rpm the piston speed would be around 5100 feet per min. Without a seriously beefed up bottom-end all i can say is.. DUCK! Even the hi reving F20C1 S2000 motor at it's 9000 rpm. The piston speed is around 4900 fpm. But I'm sure you have allready taken this into consideration.

[sniperSI]

Originally posted by B18CXr
WHAT THE PHUCK!!!!!??????

How did this post get sooooo far off track?

First off, ALL K SERIES MOTORS HAVE VARIABLE CAM TIMING ON THE INTAKE ONLY!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ONLY!!!!!!!

The exhaust gear is NON ADJUSTABLE!!!


CRV/Accord/Element and K20A3 motors only have Vtec on the intake side

TSX and K20A/K20A2 have "real" Vtec on both cams


The attached pics are mine from months ago, so if you have any question, please ask.


Trust me....

.[/I]


Yeah what he said.

[simann]

I am gonna get my friends Type-s head soon...his ep3 Si was repoed! it sucks for him but I am gonna get the head from him!

I am gonna be the first street driven Si with the head swap!

I AM SOOO HAPPY! Sucks for my friend though:(

[SiRman]

I am gonna be the first street driven Si with the head swap!

The first on EPhatch, but I don't think the first ever.
I think a couple people have already done it, a couple of A&J's customers.

[simann]

I am gonna accuse you of being a smartass.

Hahahahahah, I know I wont be the first....its ok:)

[SiRman]

:D

[ericcarver1]

How much for the head? Are you guys thinking you will look through the junk yards or buy from Honda or what? Let me know my best friend is doing this swap asap and need the head...

-eric

[simann]

you think I am gonna tell or sell it to you, Hahahahah get your own head!

I aint lettin this one go !:D

[ecsahs3]

Why don't you call Gude up and price their head upgrade. They have an K20A2 head/cams/ecu upgrade since last year. When I was researching parts last year, I sent an e-mail to Gude. They responded with the A2 package. Sorry, they didn't price quote me.