i picked up this shell from my dad a while back and i have been waiting till i had money to fix it up. i work at a body shop so the exterior isn't a problem (paint fade, clear peeling, surprisingly very little rust). however, the engine (b20a5) is locked up and apparently blown. i spoke to a engine specialist and he said the best thing to do would be to get something else to swap in it. now that i have the time and money to do so, im wondering what i should put in it. i know the b20 would be adequate but i didn't see anything listed for them besides brand new jdm engines or the b20's built for the CRV's. looking for a cheap engine that will do the job, but have no idea what is compatible. im aware there's no mounts for the b series but what about the d series or something else? open to any ideas just don't know where to start lol. thanks brandon

The easiest would be to replace it with another 3rd gen engine (b20a5, JDM b20a, or b21a1). The best option other than that would be an H/F swap. Search around the site and you'll find a lot of information on this swap.

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1991 Prelude Si ALB 4WS
2017 Ram Rebel

Welcome to your new addiction.

Junkyards have crashed preludes sometimes. So it was likely running when it got ruined. Or one with a broken automatic. But they usually get to like 200+k miles before they fail. I see those in junkyards right often, but like I said most have a ton of miles on the engine.

I like the B21, but most don't because of it's appetite for oil. Unless you can find a fresh one, avoid that engine.

Those jdm motor sellers have B20's for like $600 plus shipping cost.

Is rebuild an option?

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God's Not Dead

both of the engine mechanics i talked to advised me to just get another one. even if i paid for the jdm one it would be cheaper than a rebuild.

if i were to get another b20, where would be the best place to look? craigslist didn't have a single one advertised, and im pretty skeptical about a junkyard motor

Best is the JDM ENGINES cause they're extremely low miles. Every 3 years,In Japan, they get emissions tested and fail. Probably cause they have no EGR valve. Our US intakes DO have the EGR. sO THEY'RE PROBABLY BETWEEN 20-40,000 MILES ON THEM. They are also higher in compression.tHINK us IS 9.0:1 WHERE THE jdm IS 9.4:1. 6 or 750 bucks is the norm now for a JDM B20A. That's gonna be the cheapest way to go without worrying about high mileage. That's my cheap two cents.

^^ this.

But there would be a bit of a learning curve to getting the US ecu to speak jdm.
Info is available and members here will help ya as well.

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God's Not Dead

Think I read once that the JDM ecu's burn extremely rich .They have better gasoline over there where we don't. The US ecm works perfect still.

Most JDM engines don't come with the ecu, but if you find one that does and you do use the ecu, you will fail your local emissions testing. If you don't have local emissions testing you would probably be okay. But most people (including me) who go with the JDM b20a just keep their stock ecu and intake/exhaust manifolds. Thereby also keeping all the stock sensors. It's a direct swap, and everything from your b20a5 will bolt right on, and no need for your stock ecu to learn to speak JDM.

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1991 Prelude Si ALB 4WS
2017 Ram Rebel

^^ didn't mean to pass off bad info Luzer. Thanks for clearing that up. I thought I had heard or read there were some modifications op needed to know have to take place to get his car to run and pass smog tests.

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God's Not Dead

Honestly, I don't have to do emission testing where I am, but there should be no reason to worry about passing a smog test from swapping in a b20a if you use your existing sensors, and the engine is in good tune. If it would pass with a b20a5 it should pass with a b20a.

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1991 Prelude Si ALB 4WS
2017 Ram Rebel

Same exhaust manny as well?

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God's Not Dead

Using your stock intake and exhaust manifolds allows you to keep the stock sensors, so yes, same exhaust manny as well.

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1991 Prelude Si ALB 4WS
2017 Ram Rebel

As Mike said you just swap all USDM parts over and use your current ECU and no issues.

No internal work at all just swap all the main stuff like:
1. Intake manifold
2. Exhaust manifold
3. All sensors.
4. Exhaust.
5. You can even use the powersteering pump and alternators that come with it if not broken.

Thats what was done to mine when I swapped from a snapped timing belt B20a5 motor to the JDM B20A.

Ran a little stronger than my B20a5, due to slightly higher compression and lower milage motor.

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Sean

H22 Project Manager
www.1FunRyd.com (Clik Here)
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3rd Gen Performance Link!!


(Danny19 - JDM RH Drive) (1Funryd - H23 Swap) (B20luda - Turbo Charged H22)Representing All of 3rd Gens!!!



3rd Gen Prelude Owners are Rare Breed of Enthusiast's!!! (originally posted by: RED89si)

Thanks sean and everyone else! Uve been a great help. Im saving up for that motor now and ill keep in touch

If you don't have already.
-Engine picker and jack stands, a tire or crate to set your motors on.
-1/2" sockets, box ends and breaker bars, flashlight.
-Lot's of PB blaster/wd40 type stuff
-a couple of 2x4's
-tranny fluid, coolant, motor oil
-small tools like screwdrivers, dental picks, small sockets.
-a 40mm crank bolt grabber for replacing the timing belt.
-(optional) motor mounts
While you're at it go ahead and buy new belts, hoses, as well as a cam seal and distributor gaskets. Much easier to change out the hoses with the motor out of the car.
Go to prelude 3g and download the manual. It has instructions on removing your old engine.

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God's Not Dead

I wish the JDM engines came with that hexagonal type harmonic balancer but mine didn't.Had to use the old prybar to keep the flywheel from spinning.

^^ really? Good to know.
My son's jdm H23 came with the big boy size hole of 50mm...

I had a mustang once that the hb had holes. I used a pair of ratchet extensions in a pair of holes and a big ole pry bar between them as opposite leverage against the bolt.

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God's Not Dead