A20A Carb to B20A

[ragerunner]

Hi guys, I'm from Malaysia, have an '89 CA5 3rd gen Accord running the A20A carb engine. The current engine hasn't been working optimally for the past few years now and as such hasn't been able to serve as a reliable daily driver as before. Currently it runs just okay but the fuel consumption is unacceptably high, I'm told that this is most likely due to the dodgy carbs that this gen of Accords are apparently infamous for.

A B20A swap seems like an attractive solution since it runs fuel injection and has much more power. I've been on the lookout for a B20A motor for a while now and recently found one "Blacktop" model from an '87-'89 CA3 model. The motor comes as a "halfcut", meaning it's complete with an auto tranny, front and rear axles, wiring and ecu, dashboard, fuel tank and the like. These motors are pretty rare where I live, I come across only one or two every year.

I've always been under the impression that every single thing from the B20A "halfcut" should bolt right into my Accord since they share the same chassis and all. However when I discussed this potential swap with my mechanic, he warned that I shouldn't expect everything to bolt on because my Accord comes originally with a carb engine, and modifications will be required in regards to the fueling, engine mounting etc.

So, my first question is this - what modifications are required for an A20A carb to B20A complete swap? I apologize if this has been discussed before as my search yielded no results. I would appreciate it if those with experience could list the modifications needed for such a conversion, or whether it is merely a plug and play affair.

I would like to clarify that the purpose of this swap is not to look for crazy power or outright performance; but merely to revitalise the car for trouble free, everyday driving. I must say that my mechanic is rather discouraging with regards to this swap, as he thinks that the car is not worth restoring considering its age and similarly weakened chassis, and reckons that it does not make economical sense to spend more on the car that it is currently worth. It is hard to argue with him on that, but the cost isn't exactly prohibitive, and if this could give the Accord a good many more years of life on the road as a reliable performer then why not? Besides, the car has sentimental value for me and my family, and was a pleasure to drive before it started giving problem after problem.

My mechanic also warns that these motors, even the B20A (which is less common than the A20A here in Malaysia) are almost obsolete and should I run into any problems, finding parts will be quite a nightmare. With regards to that, my second question is this - similar to how carb issues plague the A20A, what are the commonest issues, or problems running the B20A? Are parts such as driveshafts, a/c compressor or gearbox, just to mention a few, prone to failing? Is it a headache to run and maintain?

Your opinion and advice are much appreciated, thank you and cheers

[Hazwan]

Oh hey I'm from Malaysia too. It should swap right in without any issues and you really shouldn't have any issues since you have the complete front cut and the rear tank as well. You would have to run additional fuel return line all back into the tank though but that's a small issue really. Mounts are the same and it really shouldn't be an issue since you are basically swapping from another 3g into another one.

Parts wise, I gotta warn you, they aren't easy to come by here in Malaysia. Expect few days of wait or even more to get them ordered and stuff if you need any specific B20A parts.

What exactly is the issue with your current carb? I just happen to know a thing or two about the carbs setup (check my build link in my sig) so I might be able to help! Where are you exactly? I'm in Taiping.

[ragerunner]

Hi Haz, so good to hear from you! I'm from Puchong myself. I finished going through the 13 pages in your build thread (currently scrolling through your carb thread) and I must say you're UH-MAZING! Your DIY skills (calling them that ain't close to doing them justice), your photography, and man, your English! It's remarkable how well you write, particularly considering the low standards of this language in our country, to put it mildly!

I haven't been driving the CA5 for a while now (it's currently in the hands of my brother, who's in college) and I'm not mechanically inclined or knowledgable enough to know what was the issue with the carb. IIRC it was previously having idling issues and the engine was very sluggish. I'm not sure what was done during the one year or so when my dad placed the car under the care of an uncle who has mechanical skills, I think the carb may have been 'serviced' but I can't confirm.

Anyway the car came back with its idling rather improved; it wasn't as powerful as before but then again it was never a sprinter. The biggest issue since then, though, was the fuel consumption which was at an all time high - ~5km/L no matter the driving conditions. It has also required a slew of repairs in the past year or so - a transmission overhaul, power steering failure, ongoing AC compressor leaking issues and faulty rear drum brake, just to name a few. The undercarriage, too, clanks and clonks like nobody's business when going over uneven roads.

It is all these factors, combined with the ongoing fuel consumption issue, which leads me to believe the B20A swap along with the transmission, front and rear axle and the like, could be what my car needs. The odo reading on the halfcut is merely 7xxxxkm, and the engine looks rather mint considering its age. The undercarriage and transmission should be in much better shape than my car's, and the rear disc brakes are a plus. I was quoted RM4k for the halfcut, which I feel is rather steep for such an old model but there's basically no more supply for these motors anymore.

When you commented on the B20A parts being hard to come by, did you mean ordering them from spare part shops, searching at yards (chopshops) or online through eBay? Since you've had much success with the carbs on your Lude, would you recommend me fixing the carbs instead as well? A brand new CA5 carb is practically impossible to get; the common solution, to retrofit carbs from Protons, ain't cheap either (rm1k plus new) and requires bracket fabrication as well. Besides, it wouldn't solve the car's other issues..

[Hazwan]

Well thanks haha .

5KM/L is horrible My bike carbs gets around 8KM/L normal city driving and around 10-11KM/L on highway. And I have 4 times more carbs than you! Something is awfully wrong with the carb thats for sure.

All those repairs you mentioned are normal for a 28 year old car. As for the B20A parts, I'd say all of them - spare parts shops, yards and online. The parts are out there but don't expect them to be readily available when you really need them. I know someone who are having a hard time looking for a timing belt kit and took him a while to actually get one ordered.

As for the stock carb, I know a thing or two about them and if you could get the car by my place, I may be able to help. I do have a spare freshly rebuilt carb sitting around if you need it? I mean its gonna be a lot cheaper and less of a headache than swapping the whole new engine. Worth a shot.

I gotta say most mechanics here aren't familiar with older Honda carbs and they usually managed to get the car running worse after they touched it