mtseidl

I am swapping my SH a4 block with a usdm h22a1 block. I see a lot of threads about the a4 to jdm a1 swap but nil on usdm. Same swap?
I have an APEXi Power FC stand alone ECU, Do I have to worry about this OBD1 to II shiz?

So far I got
H22a1 Crankshaft
Tranny with shaft
new cv axles for base prelude

The wiring harness is an a4 sh harness, the head is a4, there is no stock ECU it is stand alone and already wired into the harness. Will the a4 dizzy work, will the 98 oil pump work on an a1 block? I have done tons of research and have gotten mixed information.

The a1 block was bare when I got it so I am working with all SH a4 parts. What else am I going to have a freaking problem with?

bigblue7t6

In general you should be fine with the route you are going. What mixed information are you reading? I dont see where you should run into any problems.

snobordboy

Agreed, if you are swapping blocks and trannies, you are on the right path. You will have some leftover plugs from the ATTS system, but as long as you keep all the other sensors and wiring as-is, you will be good. The only possible issue may be the oil pump, not sure if there is any difference due to the change from 55 to 50 mm mains.

mtseidl

Well, most of the information that I have been reading was for the a4 to jdm h22a1 or h22. They talk a great deal about the dizzy being swapped over. If this is just for passing smog or running a stock ecu than I should be good.
Also, even thought the oil pump Part#s are different, when you order an aftermarket oil pump they come from years 93-01. I too questioned the main journal issue. I have everything at the machine shop getting balanced (entire rotating assembly). Dude blueprinting did not say a word about the pump.
But anyway, this is whats going into her.

Block

H22a1
Balanced a1 Crank
Clevite 77 Race Bearings rod & main
AERP Closed Deck Sleeves std bore
Crower H beams
Wiseco Pistons
ARP Hardware
Timing kit
OEM water pump
OEM oil pump
Looking into removing Balance shafts and getting the kaizenspeed eliminator. (chime in if anyone has experience + or -)

a4 head
Crower Valves, titanium retainers, and springs
minor port and polish
Crower stg 2 Turbo Cams
OEM Gaskets (Entire head kit)

Turbonetics T3/T4 turbo, fresh from rebuild and ceramic treatment
Delta IV wastegate
Turbonetics Raptor BOV
Spearco Intercooler
Greddy Turbo Timer
Manual boost controller ( until I get the adapter for the Power FC, then the world will be at my fingertips)

P25u Transmission (long gears to stay in boost and cut down on spin)

Fuel Delivery
Walbro 255 fp
Fuel Injector Clinic 775cc injectors
APEXi Power FC w/ Commander stand alone ECU

Tein Springs
KYB AGX adjustable struts
HKS HI Power Exhaust
DC Lower sway bar
Tanabe upper sway bar

I don't know what I am going to tune her to, boost wise. The block will hold anything I throw at it with those AERP sleeves. 20- 25 lbs prolly. Going for 400 but I wont push it if it doesn't feel good.

Need
Adj Cam Gears
ENDYN generic oil plumbing for head........

Please let me know what I am missing, or where I am messed up.

I'll post pics of the build and dyno sheet as soon as I can get it back together.

Fliptard

if you use an h2a/h22a1, you need that crank, h22a4 have bigger mains, so the crank is a tad bigger for the mains. a/a1=50mm a4=55

mtseidl

Yea.... I got it listed as parts on hand.

mtseidl

5mm is substantially bigger from a machinist's point of view.

gstrudler

'97's were 50mm mains, so if your old block was from a '97 you're in luck and don't need a new crank; anything '98+ and you'll need a new one. The difference in part numbers for the oil pump assembly is likely because of the added TDC sensor for OBDII. Check part numbers between '97 and '98; if they are the same then it has nothing to do with the crank. If the numbers are different between, say, a '94 and '97 then it is likely the sensor mounting. If you are using that sensor, you will need a compatible new oil pump if you are not re-using your old one.

mtseidl

I already have the a1 crank, the block was a 98 and spec'd 55mm. I have a tranny and the a1 block. I think I need a h22a1 oil cooler filter housing. The two housings look different where they connect to the blocks. I may be able to machine an adapter plate and make it work. We shall see. the distributor talk from obd1 to obd2 is what is throwing me off. I just don't understand it I guess. I am not using an OEM ECU and I do not have to pass smog. The a4 set up I had was already boosted so I have the converted injectors.

gstrudler

If the setup worked previously you don't need to change the distributor. You have to change the distributor over when you are also changing over the ECU from OBD2 to OBD1, but you're not doing that so you don't have to worry about it.

mtseidl

word... Thanks fellas, I will do a complete write up with pictures as soon as I can.

mot3020

result?

shawn44

im doing the same to 2000 sh prelude how did yours turn out

snobordboy

I doubt you will get much, the thread is 4 years old and the user hasn't been on Honda-Tech in 2 years.

The user never said if he had gone away from the SH tranny and ATTS setup or any of that, so who knows what he ended up doing.

ESP.net

If you have an SH and using the SH ATTS trans it will not work with the H22A1 regular H22 motor. Oil filter is on driver side of block on SH for a reason. The midshaft 3 holes are in different position on the SH block. I believe the ATTS unit also bolts to back of block of SH which has its prevision for.

Only way is to not use ATTS unit and swap both a NON SH H22 and Transmission.

If you tried to reuse the SH ATTS trans without the ATTS unit and a normal midshaft you will be coming up short on the 3 bolt holes on the back of the block about an inch off on all 3. It sits further in the transmission.

ONLY smart way is to just get another SH Motor...

Or Full NON SH H22 motor and transmission, midshaft etc.
H22A1 would want to swap your SH intake manifold to the H22A1
since car is obd2 injectors on the SH etc. Put on the 98-01 Prelude obd2 oil pump with the crank angle sensor since the car came with one it will need that to start.