So I am currently running FSP in SCCA autocrossing. I want to go to Street Modified probably next year and I am trying to decide which motor I should run in my 93 Civic coupe.

I am trying to decide between a D-series with a turbo or a N/A K-series with the goal of hitting about 250-300hp at the wheels.

 

Why not B-series?

Of all options, a B18 would be the easiest to swap in and achieve those power goals on a completely stock engine with a small turbo like a t28.

 

Honestly it seemed like it would easiest to either not do a swap or go with the newer engine then to swap and go turbo. But I have no reason to not go with a B-series.

 

Well to get a D series to that power level, you would have to pull the motor and put new internals in it anyway. If you're going to pull it, may as well drop in a stock B series which might actually cost less than building the D, if you include machine work and assembly. Then the turbo setup will run you the same either way, but you will hit your goal much easier with the B plus have room to grow.

 

I'm with 2x0 on this one. Why not consider a B series? K series is gonna cost you more to buy, mount and tune for. Whereas you already have most of what you need to do a B swap and then turbo it.
to do a K swap, you will need new mounts, K-Pro or something standalone, mostly new engine harness, shift linkage.... you get the point. It can add up really quickly and you still don't even have it running yet.
with a B swap, all you'll need is the swap and shift linkage. Your existing ECM can run that. Your current mounts will work, except the rear. You'll need the B series T bracket.

I'm not trying to talk you out of a K series, just answering your question. Ultimately, it's your car and your choice. So if money is no object, then shoot for the stars, but for sheer simplicity, I would do the B series turbo and have a blast with it.

 

He'll still need some sort of engine management for b series with turbo though it is still the easiest swap since you can use stock parts for much of it. Also vtec b-series are getting up in price now and k-series are becoming cheaper and more available. I've been running a turbo b16 for about 12 years and the engine is finally on it's last legs. I wish I could get a stock long block for $600 like you could 10 years ago. These days you are looking at $1200+ and it'll only go up.

If it were me and I was starting a fresh build right now I'd go K series for the ease of finding replacement engines and N/A power potential. I'd just compare cost, see what you can get with factory LSD or better since it will be needed at your power level goals.

 

K swaps in EF's and EG's are still fairly uncommon, and it appears they still require a good amount of custom fabrication to make them work. Then there's the harness and wiring aspect.

So, while I admit that K's are probably becoming cheaper and easier, for this platform I still think a B swap makes the most economical sense. And he'll need engine management with any of these routes, including the turbo D.

 

I was planning on going Megasquirt for engine management. My worry with the B-series is finding one fresh enough that it doesn't want a rebuild anyway.

How much horsepower can the stock bottom end of a B-series handle?

 

300-330 is usually a safe number. I put a b16a1 in my civic in 2002. Added turbo and was tuned for 235hp in 2005, then 305hp in 2009. I started taking the car to HPDEs in 2011. The engine is just now starting to slowly give out due to ring blow by, and not from anything catastrophic.

With a good tune, proper cooling and maintenance they can last a long time. Hmotorsonline.com does compression and leak down tests on all engines and they say they provide the numbers if you ask.