A2 rocker K24A1 up and running

[Heitzke]

Got the swap up and running last weekend, and have been driving/getting it street tuned most of this week.

Setup:

K24A1
A2 cam caps, rockers, cams, valvesprings/retainers
A2 oil pump and pan
A2 flywheel
CC stg. 4
Hondata IMG
3" CAI, Jackson RH, way too small catback

http://www.youtube.com/watch?v=hhBEwHYnvyg

First start up of the car. The idle was pretty rough then, but has smoothed out a bit since its been tuned a bit.

It was a concern at first, but fuel mileage doesn't seem to be terrible so far. I haven't yet finished up my first full tank, but it looks like I'll end up with 22-23 mpg with mixed driving and many many WOT runs on this tank. Vtec is set at 3k so it's been hard to drive around with out cracking it just a little bit. Maybe after the car has been running for a while I'll get to a fuel mileage map and bump that engagement point up to stay out of it.

Also a concern I read about, was the clearance with the second cam cap. I used the A2 cam caps as well with this swap and while the clearance was a bit tight, there was still room for proper function.

Overall, the motor has felt really solid all week long, especially coming from a bolt-on A3. The setup has perfect drivability, which is a good thing as this is my DD as well.


edit: thought I could link a vid from vimeo, but I guess not. I'll go host it on youtube so I can embed it.

[vonrobins]

thats wussup , the it have more top end now? pull harder

[94ex-vtec]

very interesting, definitely gonna be watching to see how this turned out. good job for thinking/doing something outside the box

[Heitzke]

Originally Posted by vonrobins

thats wussup , the it have more top end now? pull harder

Pulls harder anywhere and everywhere compared to my old A3.

Originally Posted by 94ex-vtec

very interesting, definitely gonna be watching to see how this turned out. good job for thinking/doing something outside the box

Definitely couldn't have happened without Jeremy at Inlinepro getting creative, and then Stefan at ASP showing that it was possible. My motor was a budget build from the start, and had originally planned the normal A2 head route, but it somehow worked out like this.

Hopefully should finish the tuning this week, get the exhaust fixed up and hit the dyno here fairly soon.

[11sec CR-X]

This is good to know! How difficult is it to get the rocker assembly to fit? The CRV head is just like the type S head flow wise! Now you have a cheap type S head! More info on making this work!

[rbsjnh]

Originally Posted by 11sec CR-X

This is good to know! How difficult is it to get the rocker assembly to fit? The CRV head is just like the type S head flow wise! Now you have a cheap type S head! More info on making this work!

except no lma's

[Heitzke]

Originally Posted by 11sec CR-X

This is good to know! How difficult is it to get the rocker assembly to fit? The CRV head is just like the type S head flow wise! Now you have a cheap type S head! More info on making this work!

I used the entire A2 rocker assembly; cam caps and everything, so it bolted right down with no problems. It's a cheap A2 head for a cheapass like me. Hopefully I'll be able to hit up a dyno sometime soon and see what the power curve actually looks like.

Then we'll really know if this is a decent budget alternative, even though the full A2 head would still be superior.

Originally Posted by rbsjnh

except no lma's

Right-o. Rocking the 1/2 vtec all day long.

[rbsjnh]

Originally Posted by Heitzke

Right-o. Rocking the 1/2 vtec all day long.

wouldnt this truly be non-vtec?

[chameleon]

im a bit curious, if you have the A2 rocker setup on a A1 CRV head, which means you are essentially running a vtec killer setup, why are you worried about vtec enabling at 3k if in fact you are running on vtec lobes permanently?

also where is your idle at now that you said its smoothened out ?

how do you figure the A2 head would be superior? A1 head just about outflows the A2 head, other than not having primary lobes and and engaging vtec system, anything WOT should be exactly the same between the 2.

[Heitzke]

Originally Posted by rbsjnh

wouldnt this truly be non-vtec?

No it still has functioning vtec, just half of the valves ride on the big lobe all the time. Me saying that it's a 1/2 vtec doesn't really make sense, it's more of a 1/2 vtec killer.

[Heitzke]

Originally Posted by chameleon

im a bit curious, if you have the A2 rocker setup on a A1 CRV head, which means you are essentially running a vtec killer setup, why are you worried about vtec enabling at 3k if in fact you are running on vtec lobes permanently?

also where is your idle at now that you said its smoothened out ?

how do you figure the A2 head would be superior? A1 head just about outflows the A2 head, other than not having primary lobes and and engaging vtec system, anything WOT should be exactly the same between the 2.

I just said the A2 head would be superior for overall streetability/reliability of the motor. This motor should make plenty of power how it sits, I'm just wondering how the powerband looks.

I have it idle set at 1k right now, it seems to be pretty happy right there. Part of the reason for the idle is that my catback smacks the bottom of the car since the taller K24 sucked up all of my exhaust clearance :facepalm:. I was also just addressing the fact that the video of the idle sounds really raw there due to it being the very first 20 seconds that motor had run.

[Marc P]

This is the same setup the inline pro has been doing for a while now, runs great (but my car isn't a street car)


Marc P

[94ex-vtec]

This is GREAT info

There is some really good info available from some REALLY legit people about this subject, some already mentioned.

I just sold a k24a1 for SUPER cheap, i wanted to do this but i already have a k24/k20 in my car now...........this is a motor someone could build and really push the limits on it without being scared of losing an expensive motor. Get this on the dyno ASAP!!!!!

[blinx197]

Cant wait to see this dynoed to see if this is a legit and easy route of a frank build, Im currently waiting to get my frank tuned and dynoed as well!

Originally Posted by chameleon

im a bit curious, if you have the A2 rocker setup on a A1 CRV head, which means you are essentially running a vtec killer setup, why are you worried about vtec enabling at 3k if in fact you are running on vtec lobes permanently?

how is this a Vtec killer setup if hes running the a2 cams and rocker assembly? Am I missing somethin? JW not tryna sound shitty

Also Heitzke I assume your tuning with Kpro? and if so why havent ya just raised the window slightly to 4k+? I mean in my case my engines running FUBARed for a while with Vtec switching at 2.2k.

[94ex-vtec]

Originally Posted by blinx197

how is this a Vtec killer setup if hes running the a2 cams and rocker assembly? Am I missing somethin? JW not tryna sound shitty

First watch these 2 videos

http://video.google.com/videoplay?do...19277678875693

http://videos.streetfire.net/video/VTEC-video_28019.htm

There are two sets of valves = 1 pair for exhaust and 1 pair for intake.

Normally in an A2 head during easy driving BOTH sets are operating on the "small" set of rockers, then when all conditions are met BOTH sets get engaged to the big lobes on the cams.

In this A1 setup, ONE set (either the intake or exhaust......not sure which, someone who knows chime in) is ALWAYS engaged to the "big" lobes. The other still functions normally and is on the small lobes at first then switches at a set point. So...a basic way to think of it is one cam is "always in vtec" and the other still "engages vtec."

in a vtec killer setup it is how the second video shows where the "blue" vtec lobe is ALWAYS engaged and therefore there is no vtec crossover so to speak.

Hope that helped

[blinx197]

^ No I definately understand that, I drove with a shitty k24a8 for well over 2 years before my frank was built but, he said hes got an a2 cam assembly as well as cams, its in the first post and as for the econo vtec. The exhaust side does not have a vtec lobe

[Heitzke]

I should draw out a diagram, I still may later today. Say you're looking straight on at the intake side of the valvetrain, the left rocker and middle rocker are locked together permanently, so the left valve is always going to be on the big lobe. The right valve and rocker ride on the small lobe just as normal, but when it hits the engagement point the right rocker and valve joins in the fun.

Also, just finished up my first full tank of fuel last night and averaged out to just below 27 mpg with mixed driving and plenty of WOT runs. Remember that this is in a big 'ol heavy EP3 too. I fully expect to get in the 30's whenever I figure out where the sweet spots for mpg are.

[autiger]

holy shit Mike, I never thought that kind of MPG would be reached with that setup. I guess elitetuning does a pretty damn good job on part throttle tuning

[blinx197]

ok definitely understanding it now, its pretty much running like a partial econo vtec cam assembly until the left rocker is locked in place when vtec is hit, locking both valves on that vtec lobe.

Im jw tho why doesn't it respond like a typical a2 cam assembly? why is this different from any other a2 headswap? was there more work done than u included in the first post, or did u just use a longer pin to lock the middle and right lobes in place? oooor is that somehow a side affect of the k24a1 head?

[rbsjnh]

Crv heads do not have castinha for lost motion asemblies....the pins are essentially holding the rockers locked in vtec mode
Does that help?