Nate13

Is it plausible to swap an A3 head for an A2? or TSX? I'm graduating from a 2000 d-series to a 2002 EP3 and was wondering if this was common or too much of a bitch to do? Let me know if this is too ludicrous a thought to consider.

Also, what head swap (not type R cause $) would be the most logical?

nahonda04

yes to the a2 head

josh's ep3

I've also heard of the K24a1 head being a common swap. Not positive though, there's alot about this on EPHatch.

Type-Spaz

I wouldn't swap a k24 head. I would just do the k20a2 head.

nahonda04

yup thats what i have heard

the king.

i read somewhere that there is a k20a3 with the k24 head on it runing 400hp with a turbo on stock internals

nahonda04

its possible but the more common swap of heads from the a3 is to the a2

Type-Spaz

you can hit 400 on any k engine setup turbo.....

Nate13

thanks guys, great info! Can i still use the A3 wiring harness or does it require splicing? And the a3 ECU too?

Also, short of a junkyard, where's a good place to pick one up?

Type-Spaz

you need k-pro cause the a2 is true vtec where the a3 is just intake.

go to k20a.org to find lots of heads

inkong

well personally i would just use the cylinder head i have and swap the internals like cams, cams shafts, springs, bore out the values, retainers, intake manifold (which is technically part of the upper half), head gasket, and whatever else. between all the k20 motors the difference is mostly internal, but when dealing with a k24 head it may bolt on just fine but the compression is slightly different (being less by a point or less then a point) anyway what else might you be doing with the motor.

Gtimportfanatic

doesnt help as much as the head swap.. again because the a3 has economic vtec so it wont work as good as the whole head of the a2.. i was considering doing a z1 head on my ep3 but instead ill just get a bigger IM and TB and turbo the thing..

mustclime

A a2 head swap is kinda dumb imo....the rods in the a3 are crap, reving the motor much over 7200-7400 is pushing it, you can do it for a while but in the end, the rods are going to brake. As a result of the low rev limit, the a2 head is just getting on cam when you have to shift. You are also limited by the low compression of the a3.....oh, and for the guy that thinks all k's are ok with 400 whp....good luck with that....a3's are good for about 300whp in stock form, push much beyond that and it might hold for a while but its going to fail. The k20a3 was designed to be a good gas milage, low end tq motor that runs well on regular gas, try to run it like a k20a2 and its going to fail. OH, fyi, another reason the a2 head swap sucks is with the ep3 5 speed, you drop off cam in 2-3 and 4-5 shifts. You need the 6 speed from the type-s to stay on cam.

For the thread starter, If you want to go the na rout, just pick up some bc cams and some valve springs, a race header, kpro, a cat back and call it a day...If you have a bunch of miles on the motor, think about a new timing chain, hi lift cams put more load on the chains.
The best rout for hp with the ep3 imo is a jrsc-r kit, with the right bolt ons, you can see 230-250 whp with very little under hood time. Turbos = lots of under hood time.

alexsneesby

In theory could you just do a tranny, connecting rods and a2 head and call it good? And ECU as well?

mustclime

*sigh*....look, an a3 is a good gas milage motor that has good tq and runs on regular gas. Its crank is not counter ballanced( the only k motor crank that is not counter ballanced), its rod jernels are smaller than any k motor, its oil pump has balance shafts in it that are not designed to do 8 grand. If you must "biuld" an a3 motor, pull the motor and toss the crank, rods pistions, oil pump and replace them with a2 or z1 parts....but thats not a a3 motor anymore is it? I know all you old school honda people want to do some kind of ls vtec thingie to the a3 but its not a ls motor. K motor are not b series....sorry.

ek_sleepr

HAHAHA Word .

check this guy out .

http://www.k20a.org/forum/showthread.php?t=66643