Hey guys I have a 03 EP3 and I was wondering what Honda changed in the K motors to make the 200 in the K20A but only 160 in the K20A3. I am aksing this because I am wondering if I could swap the head or sompthing to bring the horsepower up to a respectable level.

 

Your going to have to swap more then the head for it to equal a type s motor.

 

k20a = JDM Type-R motor (220hp)
k20a2 = Type-S motor (200hp)
k20a3 = SI motor (160hp)

Get a complete k20a2 swap, it's cheaper than the k20a and for the money you'll save, you could probably build the k20a2 to be more hp than the k20a. Not to mention getting replacement parts will be a lot easier.

That is if, and only if, you're going for a complete swap though. If you're not, then just ignore what I said, lol

 

Everything? Let me think of the stuff that I've heard to be different...

Cams, pistons, block, head, connecting rods, crankshaft, oil pump, ECU, exhaust, .... yeah, all that stuff is different.

Different cam profiles, complete with the high-lift, high-RPM cam lobes. Both the A2 and A3 motors have VTEC, it's just different.

Higher compression pistons.

Lighter, forged connecting rods.

Different crank.

A2 block already comes with oil squirters, for example.

A3's oil pump has balancing shafts for smoothness; the A2's does not, which allows it to spin faster.

ECU is obviously different.

Exhaust is bigger, although that's pretty easy to deal with.

Other sites with relevant info:
vtec.net
k-series.com
ephatch.com
hondata.com
k20a.org

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BarracksSi &raquo;</TD></TR><TR><TD CLASS="quote">
Different cam profiles, complete with the high-lift, high-RPM cam lobes. Both the A2 and A3 motors have VTEC, it's just different.

</TD></TR></TABLE>

Actually. The K20A3 motor has variable cam phasing. Not Vtec. Its actually known as VTC. The K20A2 motor has VTC + VTEC.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StupidSlowCRX &raquo;</TD></TR><TR><TD CLASS="quote">
Actually. The K20A3 motor has variable cam phasing. Not Vtec. Its actually known as VTC. The K20A2 motor has VTC + VTEC.</TD></TR></TABLE>

So why do they have the big I-VTEC sticker on the side of it? Wouldn't it be misrespresentation??

 

The A3 does have variable cam engagement. It operates as basically a 12-valve motor below 2200 rpm, mainly for emissions and fuel economy.

They're both "vtec", they're just different. And, as you've said, they both have variable cam phasing. That's pretty darned slick.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StupidSlowCRX &raquo;</TD></TR><TR><TD CLASS="quote">Actually. The K20A3 motor has variable cam phasing. Not Vtec. Its actually known as VTC. The K20A2 motor has VTC + VTEC.</TD></TR></TABLE>
Sorry, but you've got it wrong. i-vtec, which ALL K-series motors have (including the A3) is vtec +VTC. The difference is that the A3 only has this on the intake cam, whereas the A2, A, and the Z-variants have it on both intake and exhaust cams.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SiR Phil &raquo;</TD></TR><TR><TD CLASS="quote">
Sorry, but you've got it wrong. i-vtec, which ALL K-series motors have (including the A3) is vtec +VTC. The difference is that the A3 only has this on the intake cam, whereas the A2, A, and the Z-variants have it on both intake and exhaust cams.</TD></TR></TABLE>

stoled the words outta my head!

 

whoa , thanks i didnt know that... GRACIAS

 

So SiR Phil, I'm gonna take a big stab in the back and ask you this question because I see you are very knowledeble alot about the K20 family.. (I've seen some of your posts on ephatch.com too..) I know this has been answered before but I've never gotten a straight up information either....

but here's the question... If I was to do the complete A2 head swap and later on add Toda package (camshafts, springs, or maybe even a stroker kit) how will the bottom end hold up?.... Are the bottom ends on the all K20s the same?..

..sorry for tread jacking......79si....but I've been thinking about head swap recently for myself also....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EP3tune2RULE &raquo;</TD></TR><TR><TD CLASS="quote">If I was to do the complete A2 head swap and later on add Toda package (camshafts, springs, or maybe even a stroker kit) how will the bottom end hold up?.... Are the bottom ends on the all K20s the same?.. </TD></TR></TABLE>
No, the bottom ends on all K20s are not the same. Read BarrackSi's first post in this thread, and you'll see the differences.

Besides... if you're going to do the headswap, you'll want to do the 6-spd tranny swap as well... and for the cost of doing a separate K20A2 head and tranny swap, it would cost about as much as a good deal on a whole A2 engine.

 

ok...can the k20a2 be swapped straight into the ep3..just the motor ? or does it have to be a complete swap ?
wondering all this ?
cuz i gave up on gettin an s2k or 350z..soo ep3 it is!

 

for the EP3!