K20a3 block k20a2 head????

[Ep3crazy]

Ok im pretty much new to the k series . Nd it does not take much to knw the ep motor sucks. Sooo i was wounderin if its possible to keep my stock block nd swap the a2 head nd wat would be needed... Nd would i need to swap my tranny to a six speed nd change my wire harness.. Im planning on gettin k pro. So if anyone has done this or knws how to do this i would appreciate it

[whatsvtec]

It's a waste of time. Do some reading around and you'll find that the k20a3 bottom end can't handle the high rev's. You'll be looking for a new bottom end sooner rather than later. The connecting rods are too weak, our oil pumps are too weak, and the rod journals are too small. You'll be picking pieces of block out of your oil pan.

[MugenReplica]

It's a waste of time. Do some reading around and you'll find that the k20a3 bottom end can't handle the high rev's. You'll be looking for a new bottom end sooner rather than later. The connecting rods are too weak, our oil pumps are too weak, and the rod journals are too small. You'll be picking pieces of block out of your oil pan.

Higher weight oil, say Rotella synthetic 5w40 and 8200rpms is an easy target. Hell, Chunky, SuperchargedK20, and Gearhead Geek(the original a2 head swap) had rev limits above 8500rpms. Chunky did it daily for 160k, superchargedK20 for quite awhile (and was supercharged and cams swapped), and Gearhead Geek's car (literally the original K20a2 head swap Ep3 done in 2003) is still running at some dealership or with an individual somewhere. The myth that it's not a "good" mod is just that, a myth. If you're on a budget and can only get the K20a2 head. DO IT! then save up for a K24a1, throw it in your garage, and when you're K20a3 eventually dies (or you get bored with no torque), just use your K20a2 head. Plus the mechanical knowledge you'll get from head swapping is well worth the investment.

[MugenReplica]

Time for a little history lesson for those who haven't been around since 2002.....

*Honestly, the myth that the modification is not worth it, was perpetrated by a member named Anjapower.



-Starting back in early 2004, Gearhead Geek performed the first K20a2 head swap onto a K20a3 block.
http://www.ephatch.com/forum/showthr......&highlight=

-After working out the bugs and realizing that the K20a2 ECU worked on a head swap, but just barely, he upgraded to Kpro.
http://www.ephatch.com/forum/showthr......&highlight=

-Anjapower, now a friend of Gearhead Geek, hits the drag strip with just a couple of modifications to see where it will take him.
http://www.ephatch.com/forum/showthr...rip&highlight=

- In early 2004 following Gearhead Geek's success, Anjapower contemplates the K20a2 head swap.
http://www.ephatch.com/forum/showthr...ne.&highlight=

-Mid to late 2004, Anjapower pays a mechanic to install the K20a2 head onto his K20a3 block.
http://www.ephatch.com/forum/showthr......&highlight=

-Desperate and needed a tune, Anjapower rushes to Innovative Tuning in Buffalo NY where Mike pulls an unprecedented 197whp on a k20a2 head swap.
http://forums.clubrsx.com/showthread...ght=K20a2+head

-Late 2005, Anjapower parts out after what he calls disappointing 1/4 times of around 14.4 to 14.5 @ 95-97mph because he kept falling out of VTEC with a rev limit of only 7.7k and 8k (and later bumped to 8200rpms). After swapping the K20a3 head back onto the K20a3, he blows the engine.

-It goes viral through the forums that the K20a2 head swap is not worth the budget mod it should have become and it will blow K20a3s.

-Late 2006 or early 2007, Anjapower comes clean that he forgot to add coolant to his engine after he himself tried to swap the K20a3 head back onto his ep3 (remember he paid a mechanic to swap the head on). The K20a3's destruction was NOT because it couldn't take 8200rpms, but because it could NOT take a bone dry overheating engine.


If you believe the K20a3 can't handle modest revs (8.0k to 8.7k) for brief stints, PM superchargedK20, chunky, or Gearhead Geek.

Oh, swap an a2 oil pump in if you plan on longevity (50k+ miles) at repeated 8.2k revs or higher.

I hope that explains all of it.

[Inn-Tune]

-Desperate and needed a tune, Anjapower rushes to Innovative Tuning in Buffalo NY where Mike pulls an unprecedented 197whp on a k20a2 head swap.
http://forums.clubrsx.com/showthread...ght=K20a2+head

I was searching for something and this popped up. What a blast from the past. I can't believe that was about 7 years ago. I had to make a new login because my old username is longer than allowed now.

[whatsvtec]

Higher weight oil, say Rotella synthetic 5w40 and 8200rpms is an easy target. Hell, Chunky, SuperchargedK20, and Gearhead Geek(the original a2 head swap) had rev limits above 8500rpms. Chunky did it daily for 160k, superchargedK20 for quite awhile (and was supercharged and cams swapped), and Gearhead Geek's car (literally the original K20a2 head swap Ep3 done in 2003) is still running at some dealership or with an individual somewhere. The myth that it's not a "good" mod is just that, a myth. If you're on a budget and can only get the K20a2 head. DO IT! then save up for a K24a1, throw it in your garage, and when you're K20a3 eventually dies (or you get bored with no torque), just use your K20a2 head. Plus the mechanical knowledge you'll get from head swapping is well worth the investment.

You're the man!
Thanks for the correction, I guess I didn't know that many people had success with it. All l I had heard was other peoples failures. Personally, I would never bother revving the bottom end that high.

Good luck to you though! Make sure to post your build!

[MugenReplica]

You're the man!
Thanks for the correction, I guess I didn't know that many people had success with it. All l I had heard was other peoples failures. Personally, I would never bother revving the bottom end that high.

Good luck to you though! Make sure to post your build!

Hey man, glad I could help. I hope the post didn't come off as abrasive. I didn't mean to direct it at you.

I only meant to put the myth to rest. YES, a full K20a2/K20z1 swap is better, but a K20a2 head swap is not worthless, especially with the amount of parts (and tuning) that have become available since Anjapower did his swap. It is a reasonable swap for those on a budget or for those who just need a little bump in power. If you truly want decent OEM power though, upgrade to a K20a2/K24a1 frank swap.

[whatsvtec]

Hey man, glad I could help. I hope the post didn't come off as abrasive. I didn't mean to direct it at you.

I only meant to put the myth to rest. YES, a full K20a2/K20z1 swap is better, but a K20a2 head swap is not worthless, especially with the amount of parts (and tuning) that have become available since Anjapower did his swap. It is a reasonable swap for those on a budget or for those who just need a little bump in power. If you truly want decent OEM power though, upgrade to a K20a2/K24a1 frank swap.

No offense taken at all! Knowledge is power, and we all know our little k20a3's can use all the power they can get


So, to the OP. Do you already have a head lined up for the swap? How much do you think it's gonna cost you to get everything in and running?

[MugenReplica]

You can definitely do that. The most whp you'll see NA is a touch over 200whp because of our low compression.

If you are bound and determined to do a K20a2 head on the K20a3 block, get a OBX or Private Label race header, any 2.5" ID exhaust, RSX Type S CAI (any brand), a Maxbore throttle body, RBC or RRC intake manifold, and a Z3 intake cam and Z1 exhaust cam (if you want to stay OEM). I guarantee that will put you OVER 200whp NA.

The other things I'd add would be a Mugen or Spoon head gasket (to bump compression, although you shrink your quench area) and a CRV final gear drive at 5.062. You're car will be much quicker than anybody expects it to be.

After getting Kpro, make sure to bump the rev limiter so you don't fall out of VTEC between shifts.

[i_love_my_ep3!]

man your post was great gave me the whole history in 3 thanks for sharing

[lldiesel386ll]

john--one of the few resident ep3 historians

you do learn something new everyday though--i definitely came from the 'its not worth it' camp due to anjapower's experience. i never got the back end of that piece of information.

[obsoletearturo]

Mugenreplica ate you on the Facebook ephatch site? Pm me

[Jankboyzep3]

All of you are mvp im somewhat new to the ep3 life but ive had 3 k20a3 in total base rsx auto rsx and my current ep3 my plan is to do the a2 head swap with rbc intake kpro v4 i currently have a cold air intake set up pullling in air at 70-80 degrees with dc sport longtube headers and a cat deleted catback stock exhaust but i keep getting o2 and cat codes along with knock sensor code which i put a new one and it still came up and after i drive for a bit sometimes it goes into limp mode it gave me a code i got in my rsx once that i had to replace the vtec solenoid so i did that and it still came up after a week can anyone enlighten me a bit please lol