CharlieS

Hi guys, I'm having issues finding information about whether or not my ECU from my 1997 Base Prelude 5-sp would match up with the JDM H23A Blue top motor.

I bought my Prelude about 2 weeks ago for $625, clean interior/body, but the previous owner said the engine was blown. Two days later, pulled the engine, disassembled the head/block and found internal damage in the block but the head was fine. Rather than finding a new block and rebuilding the engine, I would rather buy a new used motor to swap in, and thought the H23A would be a good swap rather than spending $1,500 + shipping on a H22A.

Since the biggest difference between the H23A and the H22A4 is a larger bore/stroke and practically the same head as the H22A4, shouldn't my 5-sp tranny from the H22A4 bolt up fine? Also, will the P5M ECU run fine with the H23A?

Any input and past experience would help greatly.

Thanks in advance!

B serious

iTrader: (1)

Yes the ECU will work. Yes the trans will work. You need to buy a USDM oil pump (buy it from Honda), and re use your USDM crank gear and crank sensor. This is true for any JDM motor. You also need to swap your H22 driver side mount bracket. You'll need to shave your trans bracing down to fit the H23 oil pan.

Use your USDM harness and injectors and intake manifold, as well as the coil and distributor.

Any sensors that are broken...replace them with your H22 ones. Leave your ECU plugged in and use it. Just remember not to rev it past about 7500RPM. The H22 ECU allows 8200RPM.

Re use the H23 throttle body as it is larger.

Do the timing belt. You have to remove the T belt to get to the crank gear anyway. It's difficult to shoehorn a H22 belt on. So do it while the motor is out. Buy the T belt, tensioner, tensioner bearings/pivots, and balancer belt, at the very least. Honda stuff is better than aftermarket. Go with Gates brand if you go aftermarket. I always buy front and rear main seals as well as front/rear cam seals and a distributor O-ring when I do all that. Always buy seals from Honda.

Probably a good time to buy a clutch and either have your H22 flywheel resurfaced or replaced. Exedy makes a good clutch for Hondas. The stock replacement should be like $130ish.

Sites to help you:
Jdmenginescorp.com
Bernardiparts.com
Rockauto.com

CharlieS

Thanks very much for all the information! I greatly appreciate it. I'll be ordering my engine within the next couple of weeks.

tegon-gsr

Nice info I might be buying a blue top to swap into my 5th Gen Lude