JDM H23a Bluetop Swap Guide for 93-97 Accord

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JDM H23A Bluetop Swap Guide​


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I've seen checklists for swaps like this but I thought I would give my .02 from having done this personally.

For the H23a into a 93-97 accord it's not just about a motor and a car, in a lot of ways there's kind of a theory-crafting that goes into it. For this swap, the plan was always to run it OBD1 off of a P28 ECU.
So consider,

H23a Bluetop motor specs per wikipedia (take it for what you will)

Found in the Japanese 1998-2002 Accord Wagon SiR (CH9). It produces 200 PS (147 kW; 197 hp) @ 6,800 rpm & 163 lb·ft (221 N·m) @ 5,300 rpm and comes with a "blue top".

Found in the Japanese 1998-2002 Accord Wagon AWD (CL2). It produces 190 PS (140 kW; 187 hp) @ 6,800 rpm & 163 lb·ft (221 N·m) @ 5,300 rpm and comes with a "blue top"

To the best of my knowledge there's not a whole lot of difference between the two motors, and I'm not sure which one we got. I did notice however, that the exhaust manifold it came with was very thin and paled in comparison to even a stock H22 header. I've read that according to dyno numbers gains from a header on a H22 are minimal but I'm expecting to get a bit from the Megan header we installed. The manifold and cylinder head were indicative of a 98-99 model, having "PGMFI" stamped on top of the intake manifold, which has a JDM H22A head, with a "stroked" block for the 2.3L displacement and 10.6:1 compression.

So now that we know a little bit about the motor, lets talk about the CD chassis.

The 93-97 Accords are cool little cars. Coupes and sedans are readily available, usually stock, and there's a surprising amount of factory 5 speed cars out there. CD5 is a 4 door sedan model, CD7 is a 2 door coupe.

He wanted a 4 door, and I suggested we hold out for an EX model.

Why an EX?
Rear disc brakes, pre-wired for VTEC (more on that coming later)

Ethan picked up a 1996 Accord EX (the 96-97 models received a facelift and OBD2a [96-97] is similar enough to OBD1 it doesn't complicate much) with 230k miles on it for 600$. Bone stock, 5 speed CD5. Tan exterior with tan leather interior. The electric drivers seat was busted, and both front seats were in bad shape. We drove two hours, got there, and met the Russian family that owned the car. Fortunately the daughter spoke enough English to translate, and that was when we found out it wasn't starting currently. I noticed the fuel pump was NOT priming when the ignition was keyed to "on", and after investigating the fuses and main relay associated with the fuel system I deduced it was the fuel pump. We had just finished explaining to the daughter that we liked the car, and would gladly buy it if it ran. I explained that I'm a mechanic and believe it is the fuel pump but I could not replace it in their backyard but if they fixed it we would gladly come back and buy the car. She relayed it to the old man, who went over, whacked the fuel tank with some sort of metal thing a couple times and then started the car. The car was priced so cheaply because it didn't run, and they honored the agreed $600 price.

The EX model has a F22B1 stock, which is a SOHC VTEC motor that puts out

Max Power: 145 hp (108 kW) @ 5500 rpm
Max Torque: 147 lb·ft (199 N m) @ 4500 rpm

More than a D16 or B18b1 for sure, but still lackluster numbers especially in a chassis that weights 3k+lbs stock. It is a fun little motor for cornering though, which a smooth power curve that accelerates out of corners with authority.

So back to the "Theory Crafting" bit...
Basically at its core Integra and Civics are related to each other in a lot of ways, and the pairing that sometimes goes less noticed is Preludes and Accords being what I would call "first cousins". The H23a is basically a factory stroked H22a. This means it is basically the same motor that came in 92-96 Prelude VTEC models, and in all 97-01 Preludes. F series and H series bits are largely interchangeable which give you a fair amount of options but obviously the Prelude was geared towards performance so you'll want more prelude stuff than accord but a combination is required to make the swap work.
For this swap we used the manual transmission from a 1992 Prelude SI, because it had comparable ratios to the 97-01 h22 tranny and was significantly cheaper and this particular one was very clean and from a car with low miles and from a salvage yard that offers 3 month warrantees on parts. You can use the Accord transmission but the long gears will make the car feel a lot slower. IMHO if you're taking on a project like this you might as well go all the way

So let's talk about parts lists...
H23a VTEC Bluetop motor - 800$ from JDMFlorida
1992 Prelude SI Transmission - 400$ from Junkyard
1996 Accord EX Automatic Engine Harness
P28 ECU chipped by HA Motorsports
OBD2 -> OBD1 stepdown conversion harness
1992-1995 VTEC Prelude Distributor (INTERNAL COIL)
H series Exedy Stage 1 clutch kit
No-name H series Flywheel
97-01 Prelude Water pump/Timing belt kit (includes all the seals for that side of the motor)
2.25" Megan Exhaust for CD5 accord
4-2-1 Megan Header for H22 motor
(we made our own test pipe to mate the two and delete the Cat)
97-01 Prelude Rear main seal
IACV adapter from RoskoRacing.com (great customer service, I sent him a picture of my manifold and he sent me a link to which adapter I needed)
USDM 93-01 H22 IACV (USDM is two prong, jdm comes with a 3 prong which can't be used)
94-01 Tan Cloth Integra Seats

More info coming, this is just the first post. I'm trying to type it all out in a detailed and orderly fashion.
 
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You guys have put up with me thus far so I felt it was only right I give back to the community in some sort of productive way. I write in spurts so next post will be another long detailed one but I'm not certain when I'll write it up.
 
Building the new motor:

Manual Tensioner Conversion: http://www.preludepower.com/forums/showthread.php?t=229140

Timing Belt and Seals replacement: http://www.preludepower.com/forums/showthread.php?t=288086

Why convert to a manual tensioner? Simply put, if you run the automatic tensioner and it fails and you lose tension, the belt could jump timing and your motor could tear itself up and require a rebuild. They make aftermarket conversions for the manual tensioner but I suggest doing it with Honda factory parts.
As for wiring, we used the engine harness supposedly out of a 1996 Honda Accord EX automatic because there's little to no difference from the manual harness and this one MAY have been a 1995 because it had the 8pin and 2pin connectors to the distributor. After some research I strongly believe the engine harness from an OBD1 car will plug into at least a OBD2A vehicle but I'd test fit it to the chassis like we did. I ended up only having to splice in injector wires (to run the obd2 injectors on the jdm mani) and relocate the IACV wire, which I haven't found a good write up for so I'll do my best to explain it below
NOTE: GET A HARNESS WITH DISTRIBUTOR PLUGS OF 8 AND 2 PINS BECAUSE THIS SIMPLIFIES THE WIRING. A 1995 HARNESS WOULD PROBABLY BE THE BEST CHOICE.

IACV Plug Relocation

On the harness, near the MAP sensor you will find a two prong round plug with a yellow and a blue wire. This is the wire to your Idle Air Control Valve, you have to take the shielding off the wire harness and trace it back and run it up along with the injector wires so it comes out with them because the JDM manifold has the IACV on the front of the manifold and thats the only way it can reach. So find the plug, peel the harness so you can see it, and re-route it to the part of the harness with the injectors, and then tuck the wire back in the loom and tape it back up.

Injector Plug Conversion

This is pretty simple as well. The black and red wires to to the yellow and black wires and these are the GROUND WIRES. I suggest soldering these and using shrink wrap to seal it.
Now, I'm listing the injectors like you would the spark plug wires, 4, 3, 2, 1 left to right when you're facing the motor.
Injector 4 = Yellow Wire
Injector 3 = Blue Wire
Injector 2 = Red Wire
Injector 1 = Brown Wire
So make sure those are the appropriate length with the new plugs and that they find their way back in the right order.

The only other weird little wiring thing I did was cut the oil pressure sensor (single yellow/red wire off the bottom of the wire harness below the manifold) and splice it to the oil pressure sensor on the new motor (also yellow and red wire)

So with these modifications you should have a plug-and-play harness with a accord chassis and a H23a. I may have forgotten a temp sensor or something like that but I honestly can't remember.

Back to the IACV, the JDM unit has 3 plugs because it has an extra sensor that our US motors do not. Fortunately the fine folks over at Rosko Racing make an adapter plate that bolts onto the JDM manifold and lets you use a USDM IACV with the two-prong plug.
This is the adapter plate we used: https://www.roskoracing.com/cgi-bin/commerce.cgi?preadd=action&key=300-049
BUT. I would suggest emailing Shawn with a picture of your IACV because there are 3 different designs depending on the manifold and he can tell you which adapter you need.
You also need the IACV from any 93-01 H22 prelude.

A/c Compressor and Alternator

Use the accord crank pulley, and your old A/C compressor and bracket, and your old alternator and bracket. They will bolt onto the new block and the belt will fit with it and the old crank pulley. The Internet says you can use a 97-01 prelude power steering bracket but we have not done this yet. I will update if we figure it out.


Next post will include removing the old motor and installing the new one.
 
His timing belt was rubbing against the belt that turns the oil pump and I didn't have time to mess with it so I sent him to a well respected local guy by the name of Neal Sutton. He discovered the tensioner brackets were bent, and I have to amend the guide and state that IF you do the manual tensioner conversion, you need a genuine honda belt, and because the manual tensioner is slightly larger in diameter than the automatic one, you will have an awful timing getting the belt on. I'm not sure how Neal did it but he originally called to inform us the belt wouldn't fit, and later confirmed he got it on after a fight.

The P28 was tuned by someone I'd never heard of because Neal was out of town and it had a B16 basemap. I'm being haunted by these things. With a proper basemap it idles fine and runs hard. VTEC pops around 5k and when it does the torque from the H23 tries to rip the wheel out of your hands. It's a fantastic motor for sure and I highly recommend it.
 
H23a Bluetop VTEC Accord vs K24 6 Speed TSX

Car is a beast. The TSX is stock basemap though, with a reflash I'm sure the TSX will either match or beat the accord.
 
so update almost 2 years later, he's been dailying it ever since but he's moving and can't take it with him. I've got a project right now and I'm really trying to not spend money on non-essentials, but he says he wants me to own the car and take care of it since i built it for him. He said he'll sell it to me for 1k, just so he can make sure it ends up in good hands (he loves this car lol). So in April I'm gonna buy it from him and take it over. So updates on this car may be coming still
 
For $1k, you really can't go wrong lol. I'd scoop that up for a daily in a heart beat
 
Yeah I'm thinking do the body and paint, figure out the power steering, and add it to the roster. I've got those 17" Enkeis in Accord 4 lug which would probably look great on it.
 
if no rust offer him like 800 because you dont need the car or another project and lets be realistic guys cd5/cd7s are literally dirt cheap in todays market (over 20 for sale in 65 mile radius of ATL for under 2k) - if you are going to buy/sale/flip cars take it from me if you are going to buy something with the slightest intent of investing time or money into make sure you have it at a price where you could easily quick sale for 20-30% profit no problems ... example if you buy it for 800 and you get in a pinch you could easily advertise and quick flip the car for 1000-1200 as is with some cleaning in a weekend that way you arent sitting on something that with A cost you space B cost you money C arent sitting on it for exactly what its worth , end of day even with swap in todays market its still a 1500-1700 rust free vehicle on its best day. Even with some wheels and a lip etc you still will be barking and squatting on it for 2k range $$$
 
if no rust offer him like 800 because you dont need the car or another project and lets be realistic guys cd5/cd7s are literally dirt cheap in todays market (over 20 for sale in 65 mile radius of ATL for under 2k) - if you are going to buy/sale/flip cars take it from me if you are going to buy something with the slightest intent of investing time or money into make sure you have it at a price where you could easily quick sale for 20-30% profit no problems ... example if you buy it for 800 and you get in a pinch you could easily advertise and quick flip the car for 1000-1200 as is with some cleaning in a weekend that way you arent sitting on something that with A cost you space B cost you money C arent sitting on it for exactly what its worth , end of day even with swap in todays market its still a 1500-1700 rust free vehicle on its best day. Even with some wheels and a lip etc you still will be barking and squatting on it for 2k range $$$

If the car is worth $1500 minimum (worth more, IMO), then is he not exceeding your "quick flip 20-30%" recommendation at $1k purchase price?

Seems fair to me.
 
If the car is worth $1500 minimum (worth more, IMO), then is he not exceeding your "quick flip 20-30%" recommendation at $1k purchase price?

Seems fair to me.
yea its really not a bad deal but yes he instantly is over the 20-30% profit if he counts all his time and labor as $0 , idk yes its probably WORTH more than 1500 but private party sale on a northern car no ac etc it would either be somebody really wanting one , prob worth more to put a f22 back in it and sell it still for 1500 and then sell the h swap
 
It's a Florida car with no rust and the body is very straight for what it's worth. AC works and interior is mint. CD5 chassis has a more narrow appeal but it's a complete car. It's a paint job and power steering from being perfect. Your F22 idea is low-key retarded I'd be doing thousands of dollars of billable labor to make an extra 500. As it sits I could get 2k for the car EASY.
 
It's a Florida car with no rust and the body is very straight for what it's worth. AC works and interior is mint. CD5 chassis has a more narrow appeal but it's a complete car. It's a paint job and power steering from being perfect. Your F22 idea is low-key retarded I'd be doing thousands of dollars of billable labor to make an extra 500. As it sits I could get 2k for the car EASY.

Yup. I would daily drive this thing. Looks clean and fun.
 
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