I was in the local pick-and-pull looking for a TCU for my 94 EX. They had a 95 Prelude with automatic, so when I was double checking the numbers I found the motor was a F22B DOHC. It seems that JDM motors for the Si Preludes were F22B and not H23A1. So I was wondering if the head from this F22B would fit Accord F22B motors? Say, an F22B1 in an EX?

 

yes it will fit, but you would have to use the timing belt from an 85 dodge caravan 2.5l for it to work it a 126 tooth belt, h23 won't work, I'm doing an F22B DOHC turbo swap in my 93 accord coupe now

 

Better off to just swap the entire engine.

 

If it really is an F22B I would pull the complete engine/harness and ECM/TCMs. Check the trans too, it might be a proper MP1A-1(LSD) AT, which would be worth getting. Even if it was an MP1A it will have better gearing to match the B.

My only concern with switching out the B1 head for the B(DOHC) is the engine may not have the low-end and mid-range torque of the B1.
I would definitely change the trans out with something else, even the B1 is a bit of a dog with the BOYA trans.

 

In thinking about this, I guess there is really no point in using anything off this car except the TCU. It would be non-VTEC which would mean a different wiring harness, and I already have an MPJA trans. All this for a few more hp. Better to swap a JDM H23A. It was just something different I had not seen before, and still wonder how it ended up in a US version of the Prelude.

 

It was probably sourced as a replacement if that prelude originally had an H23A1.

 

It was automatic with the A42 control unit, so it should have come with the H23A1 motor.

 

Probably did have the H23 and it blew up, or had an FRM issue.
Japan I don't think had an H23A(non-VTEC) in Preludes. So the F22B may have been sourced for as a JDM replacement(cheaper) for the H23, IIRC both are ~160HP engines.