I never thought about upgrading my motor on my 1991 SI because I have kept it stock since brand new. However looking through all these post and seeing how it seems to be the fairly common procedure I would really like to have more power. The car hasn't been driven for 12 years except for about 50 miles a year just to get it out. My biggest concerns are what engine would be the easiest to swap out and will I be able to keep my A/C without having to remove it first? Any input would be greatly appreciated.

 

A B16 swap would be the easiest, some would say DOHC ZC but I rather have the b16. You can buy the complete swap at Hmotorsonline for a little over 2 grand. For the AC I think you need a specific bracket for it to like up properly. I think Hasport makes them.

 

A B16A will be fun and ultimately cheaper but a GSR (B18C1) will be amazing in comparison that you wouldn't regret.

 

One owner, unmolested SI that gets driven 50 miles a year?! Don't touch it! You'll only decrease the value of it lol!

If you're stuck on modding it, boost the D! If it's a healthy motor, it can handle 200whp all day with a proper tune. And A/C friendly kits are available. But you should educate yourself about forced induction first if you consider taking the superior route that I'm suggesting. Here: https://honda-tech.com/forums/forced-induction-16/%2A%2A%2Aforced-induction-forum-faq%2A%2A%2A-1024174/

 

I agree if this is a car that is in fact a civic si (88-91) with its stock engine. stock interior mint and one owner car. and the engine has 50miles per year to keep cob webs out. then don't swap it out.keep it stock one day you could sell this car as an antique and gain lots more .
don't even boost it just keep the engine healthy and running take it to the local Honda deal for check ups . but if your really wanting to upgrade engines. best would be a B16A.
but then again those engines them selves are old . along with popular so there more likely to be beat up and need a rebuild.
so point being keep the stock D16a6 in your Si.


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https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/1989-honda-civic-si-usdm-restore-2905845/

this is a guy who has kept his 89 civic si so stock. its just as or more valuable than a modified civic si.
keep it stock.


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I really appreciate all the responses. I bought this car with 1 mile on the odometer and drove it for 10 years before parking it. It has 185,000 on it now and has been serviced religiously with records. I'm no spring chicken at 52 years old but I still love the car. When my sons were younger they both wanted it but I couldn't do it. It has been sitting because I've been more into Harley's over the years but I want to start driving the SI more. I take it from the advice that maybe my best bet is to just pull the engine and freshen everything up and keep it original. It has a few places the oil is seeping and I am in the process of fixing those problems. I would like a little more power because city drivers stay on my azz and I've always been easy on this car. I could count the number of times I've red lined it on one hand. I finally attached a few pics of it sitting all alone and as you can tell it still looks pretty good.

 

well like most said its either keep your OEM engine (D16a6) or a B16A.
both engines are OBD0 and MPFI as the car is OBD0 MPFI its self. yours sons most of liked it for it being a great car overall!


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It's a very nice hatch for sure. A B16A swap will give you about 3 more ft. lbs. of torque than your D16A6 is pumping out LOL! For the money you'd spend on that swap, you could probably get a quality goautoworks turbo kit that's A/C compatible. Of course, then you'll have to drop a bit more coin for tuning. But you'd end up with a boosted D that would pull bus lengths on a B16A.