Honda / Acura K20a K24a Engine Forum banner
1 - 2 of 2 Posts

118 Posts
yeah pulling the a3 and swapping an a2 is easy but expensive. With 2 months of down time you can pull the a3 motor and build it with stronger internals.

I would say if you want to spend a penny just do a full build on the a3 using some of the parts you have now, saving you a little bit a of money and you know what your getting.

Turbo it, Tune it, drive the hell out of it!

I dont know what kind of answers you are looking for but a quality turbo install with the proper EMS will run from 2000-3500 depending on the power you want ot put down (same on either an a3 or a2)

If you want to save money but be quick a boosted a3 on 9lbs would be enough to have fun with.

118 Posts
I had asked myself the same question... How much power are you wanting to put down?

The most expensive part of the whole build is going to be the tune... I personally feel like if you change anything internally you really need a tune. Even if you exchanged the pistons with the same compression ratio you still need a tune. I wouldnt go with anything other than K-pro so you are looking at 1500 for an ecu and tune, or now is a good time to learn how to tune!

The engine itself (if moderate power is wanted) can be built for 3k Saying you do all the work yourself, minus machine work. If it was me I would go this route.

Forged 9.1 CP
Forged rods
oem bearings
A2 crank
a3 timing gear
a2 oil cooler (block needs slight modification for oem a2 cooler)
a2 coolant assymbly
a2 head
ARP (or similar)
a2 wiring harness
larger injectors (depends 550-750)
walbro 255
adjustable regulator

oil pressure
fuel pressure

all of this will give you near the same results as the STOCK a2 motor, but will handle power to around 400HP when you are ready to boost.... The a2 I believe runs 10.1 so the compression loss will loose some power but tuning will eliminate that if you are wanting to run NA for a while.

If you ARENT going to boost EVER I wouldnt bother with forged internals I would look for OEM a2 pistons, rods, and crank. Just replace the rod bolts with ARP and give the block a good hone and these internals can be found cheap used and in good condition.

If you decide to go boosted I recomend beefing up the bottom end and going .5 over so you can bore out the cylinder walls to allow for true parallelism of you piston to cylinder wall.
1 - 2 of 2 Posts