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View Full Version : B20A into 2gee



evil_s14
02-22-2006, 09:06 AM
First off, thanks for finally making a 2gee section! U guys RAWK! secondly I've done my research and have compiled the following list of parts/to-do's:
JDM B20A (2g lude year???)
matching tranny (#??)
custom shafts/axles
a little tweaking of the mounts
custom tranny mount
either EFI conversion (new fuel lines/pumps/sensors)
or ITB's or weber type carbs
88-89 VSS sensor custom mounted to tranny (to keep original cluster)
EGR solenoid & control valve (which should already be on the engine), possibly new radiator
standalone ignition system for efficiency ( i.e. MSD, CRANE, etc)
anything I missed guys? (Honda3G, Phydeaux)
What year/trim prelude do I need?
Which ECU do I need?
What about power steering, A/C, and cruise control?
Anyone know where I can get wiring diagrams?
Thanks in advance!!
BTW how much more difficult would a B-series swap be??

PhydeauX
02-22-2006, 10:23 AM
I think you have it pretty much covered.

JDM B20A (2g lude year???) In the US the 2g lude was 84-87, I'm not sure if those corrolate to the jdm years for that model. A b20a from a 3g accord should work as well.

matching tranny (#??) Yes the tranny must come from one of the modles above.

custom shafts/axles I believe you should be able to use 2g accord SE-i axles. You wont be able to use the midshaft to have the equal length axles but you should be fine with the stock SE-i parts. I'm a bit confused in the post because honda3g says that he used the stock axles but later when phrenology recants his conversation with him he says that he said the axles were custom. My gut says the 2g SE-i axles should work, but then I've never done this. Some research guyhatesmycar did shows that you can press the hubs and bearings from a 2g prelude Si into the 2g accord hubs to get the proper splines. Or if you are lucky you might find a SE-i and just grab its hubs.

The only info we have on the mounts is from honda3g's post. He doesn't seem to be around any more to ask more questions and I missed his first post so I never got to grill him on them. The A20A swap works by swapping the mounts from the 2g's ES2 on to the a20 block and dropping it right in. Both engines have the same mounting bosses so this works. The B20 mounts attach to teh chassis in the same place as the a20 mounts but I believe they attach to the motor and trans a bit diferently. I'm fairly certain that the rear mount is going to be the problem one. I believe the 2g mount was a little shorter then the 3g. I'm not certain how the 2g prelude's mounts fit into the equation though. It's front and rear look the same as the 2g. (that actual mounts have the same part numbers, but I am not sure if they are in exaclty the same place on the chassis realitive to the engine). From honda 3g's post it seems that the 2g drivers side mount can be swapped over. That was the one that worried me way back when I started thinking about the feasibilty of this. That drivers side mount is cast and the hardest to modify, the others are stamped steel and should be pretty easy to modify.

either EFI conversion (new fuel lines/pumps/sensors)
or ITB's or weber type carbs

The easiest way to get it fueled is to use an a20a1 manifold with a weber DGV or DGS carb. That said its not the highest performance option. It would work with your stock fuel system and allow you to do the engine swap and fuel system swap in 2 seperate stages.

EFI conversions on a 2g are realitively hard. Mostly because the only 2g to come with EFI was the 85 SE-i. If you find one you can souce the fuel tank lines and pump from it. Though honda3g said he had to do a custom return line on his. If you want to get the most out of it and you have an unlimited budget look into a standalone and ITB's. The dual weber sidedrafts are a cheaper solution but converting the b20a has the same problems as the a20a, you need a custom manifold. You'll also need atleast a 45mm barrel carbs to get the most out of the motor (a 50mm with 48mm chokes would be optimal if you want to be making power up near the rev limit with some cams.) The 40mm side drafts are cheap, but the larger ones are alot harder to find used and can get rather expensive new.

The crusie contol can stay as long as you keep the vacuume system and computer controls for it. (I've never looked into it but I beleve it uses a seperate computer and only takes input from the brake and clutch switches and the vss. The actuator connects to the throttle cable so you don't have to worry about linkages.

The a/c will be a lot of work. The easiest solution would problaby be find a way to connect the 2g lines to a b20a compressor (or an a20a if it will attach to a b20a block). The 2g comressor problaby won't fit to the block, and even if it does the belt systems are diferent. So you'd have to come up with a way to deal with that. I never looked deeply at the feasibility for a/c on my a20 swap. I assume that they will be similar though.

I'd be nice if honda3g was around to answer the p/s quesiton as well. The 2g pump bolts to the a20 motor, but I don't know about the b20. The good news is the 2g came standard with manual steering so if you can't make the power work a manual rack isn't too hard to find.

It should be a lot easier then a B-series swap. The mounts should be fairly close and you shouldn't have to do anything with axles or shift linkage.

andy

evil_s14
02-22-2006, 10:25 PM
OK, so it doesn't have to be a JDM engine, just 2g lude or 3g cord, gotcha! I'm guessing the ECU also has to correspond to the engine (duh, excuse the noobish question)? PS isnt a real biggie and I can always switch to the 4/55 AC system :D ! I guess the only diff between a B20 swap and a b-series swap is the fact that it would cost more to make mounts, axles, shift linkage, etc. SOOO if one were able to custom fab these parts then they could pretty much do whatever swap they wanted, right?! Just a thought, I don't want too far off the subject! Guess I'm still not sure if I should go B20A or B-series. I feel like I've reached the limit on the research for the B20A, so how bout some B-series questions? How much different are our mounts from early civics/CRX?? Maybe we could use the mount kits for those onto the 2g cords? but i guess someone would have already thought of that. well thanks for the info. I'll be sure to keep you guys posted!!

2ndGenGuy
02-23-2006, 12:57 AM
Wow this whole thread had me confused... I never realized that the B20A wasn't really a B-series engine...

For anybody else who wants the clarification, I found a good Wikipedia article that cleared the confusion for me:

http://en.wikipedia.org/wiki/Honda_B20A_engine

evil_s14
02-23-2006, 01:07 PM
Thats exactly where I found my info! Wikipedia is the $#!+

PhydeauX
02-24-2006, 01:57 PM
OK, so it doesn't have to be a JDM engine, just 2g lude or 3g cord, gotcha! You misunderstood me. It does have to be a JDM engine (or maybe from europe, they got b20a but they weren't as powerful as the jdm ones). I was stating that the years for the 2g lude in the US were 84-87 (implying that hte jdm ones would be similar years), not that they were ever available with b20a engines. We never got the b20a in north america.

Our mounts aren't close to the civic/crx at all, their mount kits wont work. If you have enough fabrication skills anything is possible. Heck there's one with a chevy 377 small block and rwd conversion.

andy

carotman
02-26-2006, 11:24 PM
Wow this whole thread had me confused... I never realized that the B20A wasn't really a B-series engine...
For anybody else who wants the clarification, I found a good Wikipedia article that cleared the confusion for me:
http://en.wikipedia.org/wiki/Honda_B20A_engine

And guess who added the 3G Accord B20A info on wikipedia? :wave:

The only problematic mouns should be the rear one like phydeaux said. The front and side mounts are the same as the A20A so you might be able to use the ones currently on your car.

An EFI conversion is easy. I mean, it's not simple to do because it's sooooo long but in the end, it's rather easy. Just need to know what you're doing. I really recommend the PK2 ECU with a chip I'm currently working on. By the time you complete the swap, the chip should be ready :D

Fuel lines should be an easy task if they work in the same way as the 3g does. The Original feed line is transformed in a fuel return line. Just change the fuel pump and add an EFI feed line. You might even be able to source your parts from a 2g lude. They use an external fuel pump just like the 2G Accord.

Get the wire harness from an A20A, mod it according to what you need and you're set.

PhydeauX
02-27-2006, 03:46 PM
The fuel lines area a bit diferent since the 2g has an external pump. Though in somce cases it makes it easier, since you alrealy have an external pump (located under a plastic cover infront of the left rear wheel). It makes fuel pump swaps fairly easy since you don't have to drop the tank. Its an inline pump so something like a walbro universal external will replace it rather nicely. The fuel lines on the 2g actually run in the cabin which makes replacing them a pain in the butt. It also means that you have to run hard lines if you plan to race and you want to pass tech. I ran an -6an (3/8") fuel line in my car and it was a hassel to get it in there. The fuel line runs in the door sill next to the main body wireing harness. Again I'm running webers so I am running low pressure high volume. You won't need something that big to deliver fuel. -4an (1/4") lines should be more then enough. I'd run both send and return at the same size. I say this because I read some where a while ago that return style fuel systems should have the same size return line as delivery to ensure the return line doesn't infulence the fuel pressure. That being said you can problaby get away with reusing the factory fuel line. Though if you opt for (or need if you plan to turbo) a monster pump like a walbro 255 then you'll probably want to run a larger return.

I'd start off with something simple to fuel it first, then as you work the bugs out move up to bigger and better things. I know first hand what can happen if you try to take on too much in a project at once. Its better to get things going in stages. Get the motor in there and run it with a stock lx carb or a cheap ebay weber down draft. That'll work off your stock fuel system and let you work out the inevitable bugs that will arise with the rest of the swap. You'll want more power soon enough and then its time to start thinking about an efi swap. Start with a stock efi system from a 3rd gen prelude. Work the bugs out of that then start thinking about custom chips, ITB's, standalone engine management, etc... Trust me it takes longer to get there, but it will make the process much more enjoyable.

andy

Ichiban
02-27-2006, 07:54 PM
i posted a thread awhile ago about the fuel line routing for efi conversion on a 2gen, but it was universally ignored. the conclusion i came to was to simply run a third line on top of the original fuel feed and vent line, and zip tie it all together. i just don't know if it will all fit under the door-trim piece.

for the fuel pump, i was just going to go with an off the shelf external efi pump, but i haven't really looked into that yet

carotman
02-27-2006, 10:14 PM
i posted a thread awhile ago about the fuel line routing for efi conversion on a 2gen, but it was universally ignored.

Well, this shouldn't happen anymore since we have the 2ng gen section up and running.

PhydeauX
03-01-2006, 09:25 AM
If I remember correctly atleast on the 85's the clips exist for the 3rd fuel line even on the carbed cars. I was able to clip my aluminum fuel line into it after I expanded the clips with a heat gun. I'm not sure if the same is true for the 84 though. I'm killing time in school so I can 't just go out to the car and look but I'll try to remember to take a look when I get home, maybe even snap a picture.

andy

Ichiban
03-01-2006, 10:27 PM
the 82/83's do not have it, but the clips might be handy for sure..i'd just use them.