Okay, so I have a 1993 (American) Honda Prelude Si.  It's got (had) an
h23a1 in it, which I managed to blow up (don't ask).  Unfortunately
h23a1's are ridiculously hard to come by and cost a fortune.  This is
sad, since the car is in unbelievably good shape for something that
old -- the body/tranny/interior make it worth saving.

Honda puts DOHC f22b's in the *Japanese* version ("JDM") of the
Prelude Si.  Note that there is also a SOHC f22b which is totally
different -- this confused me quite a bit at first.  The DOHC f22b
specs are almost identical to the h23a1.  There's lots of anecdotal
evidence on the web that indicates that the engine fits perfectly in
the American Prelude Si; one guy on ebay even sells them as "h23a1
replacements" and he's got very good feedback.  The f22b's are also
really cheap because Honda used them in the 97-00 Accord EX, which
they sold zillions of.  I can find them on ebay for $800 easy with
half the mileage of my Prelude.

My mechanic is good, and has done lots of same-engine replacements on
Hondas, but he doesn't have a lot of Honda-specific knowledge, so he's
skeptical about using a different motor.

In other words, in order to have him do this swap, I need some sort of
assurance (for me) that it will be almost as easy for him as a
straight h23a1 swap (since I'm paying for the labor), and I need
something I can show him to convince him as well (since I want him to
give me the same warranty he offers on same-engine swaps).  So
credibility is a factor here.  I also need to know exactly what parts
to buy in addition to the engine (for example, do I need a new ECU?
probably.)

I've spent a good bit of time googling for this, and I've come up with
plenty of anecdotes, but they're all vague and many are contradictory.
So, I'm kinda picky about the reliability factor.  Obviously anything
from Honda is awesome, but I'll take something a bit less reliable. 
For example, a decently detailed set of instructions found on the web
would work if it's clear from the walkthrough that the guy who wrote
it actually performed the procedure himself and it worked.  A pointer
to where I can acquire documents (specs, etc) would also work.  Like,
order this book off of Amazon or call this phone number at Honda and
pay them to send you schematics, etc.

I'm actually sort of hoping that one of the google researchers is (or
knows) a Honda enthusiast and simply knows the answer from firsthand
experience.  I just don't want to frustrate any researchers with
supurb googling skills but little automotive knowledge.

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Clarification of Question by megacz-ga on 04 Nov 2003 03:30 PST

Oh, I almost forgot.  If find a shop in San Francisco that is willing
to do the swap for less than $1,000 in labor (it really shouldn't be
more $800) and offer some sort of warranty (minimum 30 days, 3 months
would be ideal), that will also qualify as a correct answer.  I just
want my wheels back! ;)

---

Clarification of Question by megacz-ga on 04 Nov 2003 06:24 PST

One more hint: the f22b comes in two varieties: f22b1 and f22b2.  The
b1 is a vtec engine; the b2 is not.  I hear that the b2 is the one
that's an "exact fit" while the b1 requires some fiddling and
rerouting.

---

Clarification of Question by megacz-ga on 04 Nov 2003 06:27 PST

Er, scratch that; the f22b1 and f22b2 are the SOHC engines.  The DOHC
is just plain old "f22b" without a final digit.

ok so here is the deal.  i just happen to be looking into the same
thing as you from my 92 honda prelude si.  so funny i thought ok a JDM
engine for 450 and the labor of 650 and new clutch for 200 and wow a
new car for under 1500 bucks.  so i called the guys down at eric japan
engines in chicago and they sent me the following fax.  i will try to
retype it here since it is very hard to read.

F22B DOCH SWAP INTO H23A DOCH

1-all external gaskets appear to be the same between the F22B DOHC and
the H23A DOHC engine; e.g. Intake and Exhaust gaskets.

2-The timing belt to be used is GATES T132, 126 tooth belt

3-If the customer wishes to replace the WATER (H20) PUMP, they can usa
a POA H2O pump (SOHC Accord F22A Type) However this US sourced H2O
pump is a 20 tooth gear, whereas the F22B JDM H2O Pump is a 19 tooth. 
This is of no concern, since the T132 belt still has enough length to
accommodate the larger 20 tooth gear, and still be held correctly by
the BELT TENSIONER. Advise of tight fit.

4-To our experience thus far, the H2O-cooled oil filter base must be
eliminated.  There is NO strait forward way to re-use the oil cooler
from the H23A.  The main coolant pipe behind the H23A H2O pump has the
larger diameter pipe than the F22B H2O pump pipe.  The rear of the H2O
pump housing is an integral part of the short block and cannot be
changed over.  Therefore, the installer must retain our F22B main
coolant pipe, wich does not ahve the provision for the H2O-cooled oil
filter base.

5-By now, you have brobably been advised that the positions of the oil
pressure sending unit and the knock sensor are different. (comparing
the H23A and the F22B DOHC).  The USDM H23A has the knock sensor
mounted ABOVE the oil filter, while the oil pressure sending unit is
mounted BELOW the oil filter.  On the F22B DOHC, the oil pressure
sending unit is mounted ABOVE the oil filter, and the F22B DOHC does
not use the knock sensor at all.

5a-For "Mickey Mouse" customer/installers, they can simply switch the
locations of the sensors.  The customer simply has to RE-USE the
JDM-F22B oil pressure sending unit-tell them to NOT touch that unit
(ABOVE JDM oil filter).  Then the customer can grab the USDM oil
pressure sending unit (including the additional fitting); tell them to
remove the ACTUAL USDM oil pressure sending unit from the "removable
fitting"  Then, the customer can get a tap (10 X 1.25mm?) and drill
out the "removable fitting" to accept the USDM knock sensor.  Now, the
USDM knock sensor can fit into the JDM F22B block at the lower
position BELOW the oil  filter.  (Warning! This lower position is a
pressurized oil galley!  Customer must properly seal unit with Teflon
tape and use proper torque to mount this unit!)

5b-For "Picky picky" customer/installers, the customer must RE-USE the
JDM F22B oil pressure sending unit as is - the customer should not
touch the unit (ABOVE JDM oil filter) Now, the customer must locate
the "blank hole" (i.e. not threaded, but hole is already there) in the
short block; this is located just above the intermediate axle shaft
(a.k.a. half-shaft) where it mounts to the transmission.  The customer
needs to use a 12 x 1.23 mm (helicoil or guiltart -I can't make out
these 2 words on the fax)the knock sensor can now be mointed in this
hole (near the bell housing). CAUTION! to use this technique the knock
sensor should be installed LAST.  As the knock sensor is somewhat
delicate and this location is near the the axal shaft; to minimize the
chance of damage to the sensor, it is best to install this after the
engine and axles are already installed.

ok thats the end of my fax i dont know if this helps anyone at all but
its all another language to me.

this is the email i got from the guys in chicago but it is for the
SOHC engine the DOHC engine is about 200 more and the labor is about
40 more.  the guy from this email doesnt speak english as well as i
would like but there is a guy there that speaks english really well. 
i have talked to both of them and they seem pretty nice.

YES I DO HAVE STOCK RIGHT, YES YOU CAN PICK UP,
BUT BEFORE YOU COMING CALL ME FIRST MAKE SURE YES I DO HAVE.
YOUR PRICE WILL BE $ 450 + SALES TAX 8.75% = 489.38
WE OPEN MON-FRI , 8-12, OR 1-4:30
PLEASE CHECK WWW.MAPQUEST.COM FOR DIRECTION
ERIC JAPAN ENGINE INC.
3900 N. ELSTON AVE.
CHICAGO, IL 60618
TEL:(773)463-8108

ALSO I DON'T KNOW WHO GOING TO DO THE JOB FOR YOU.
IF YOU DO THE JOB MY SHOP ALSO AVAILABLE

LABOR = $ 475
OTHER PARTS = $ 140 PLUS

THANKS

JOHN LIN /ERIC JAPAN
11/4/04

Hey thanks; I actually did this job a while back... works great!

  http://www.megacz.com/misc/engine/