hello everyone. I am planning on either getting a D16z6 rebuilt for a turbo setup if I could still get better mileage than a B18c1, if not i will just do a b18c1 swap. I just have a few questions. But before that let me quickly let you guys know where I want this build to end up. I have a 92 VX hatch, I would definitely like more power without ruining my mpgs so thats why im considering the D16z6 with a turbo as well as it being easier to swap a 1996-2001 b18c1 which has an OBD2. If i get the B18c1 I plan on getting the crate engine from jegs for $3400. If I go with the d16z6 I plan on getting a turbo kit for it as well as getting it rebuilt to keep it as reliable as it can be. I hear that fuel economy can stay pretty similar or sometimes even get better with a small turbo setup and thats what I care about most. Ideally I would like to be making 165+ hp, I want to make at least 155 or else a turbo doesn't seem worth it, but if I wont get better mileage than the b18 I wont go this path. the 1992-95 civic Si gets 29/35-36 mpg city/HW with the D16z6, it also weights 200+lbs (2326-2390lbs). the 1996-2001 GSr's get 25/31 city/HW mpg, and weigh about 2667lb. Reliability is a major factor, If its the D16 I want it to last at least 250K miles. thats why I plan on getting it rebuilt instead of just slapping a turbo on. so my questions are
Which will be easier to swap, my civic already has vtec-e
which swap will be more reliable, I usually drive around 1800-3500 rpms, and id build the d16 with high quality parts
which swap would you think get better mileage If the D16 was making 170 hp, or how much hp do you think I could get with the d16 before getting the same or worse mpgs as the b18?
Any turbo kit or turbo and psi suggestions?
Would a smaller turbo on higher PSI get better mileage than a larger turbo on lower PSI? or is there a good middle?

From what I see the D16z6 pros are: weighs about 100 lbs give or take and with a turbo kit will probably still be a little lighter than the B18 which will help the cars handling around turns. Dont need to change car to obd2. Can probably get better mpgs than the b18. plus turbo noises are always nice.

The b18c1 pros are it is super reliable, especially when leaving it stock. has more torque than the d16 might end up with. Sounds better than d16. crate engine is 3400$

 

You will not get better MPG with a turbo. Reliability will always be better in a NA application than FI, barring extreme high compression/cam builds. Also note that any of the engines you listed will get worse MPG than your VTEC-E engine, assuming it's running healthy.

If your goals are only 165+HP and your primary concerns are reliability and MPG, then I'd probably advise just getting a B18B engine with matching LS transmission. The long gear ratios would likely yield similar results to the D16Z6 MPG, but the smaller SOHC engines will probably always be more fuel friendly.

Turbo kit on the D would negate any small weight benefits the D has over the B, and you're cutting hairs a bit anyway between those two engine series as far as weight goes.

 

That makes sense, I know im gonna be bettering worse mpg from these engines but thats ok since im getting a bit more power. in my 95 del sol i get about 30-31 mpg, in my civic I get about 32-35mpg. the thing I hate about the vx engine is that vtec kicks in around 2500 rpms so its hard not to use it when speeding up.Would I be able to use my VX transmission with the b18 or could it not handle that much hp?
Also I forgot to mention this but Handling around corners/turns is a big factor also, arguably the biggest factor, I dont car to much about going fast in a straight line I prefer to go quick around turns and taking them at a good speed, Do you think the b18's extra 100lbs and X amount more for the tranny will negatively effect the handling? And do you think it would be a noticeable difference in handling between a swap just a D16z6 (no turbo)?

 

Nope. I'm also curious if the overall weight difference between two fully dressed D16 and B18 engines would actually be 100lb, assuming each had the same bolt-ons and fluids in them.

You have to be a bit skeptical of reading engine weights online, even from official sources, because a lot of people have a different idea of what they want to weigh and count as part of the "engine" when they do that. A longblock with no manifolds, pulleys, or fluids will weigh a LOT less than one that has them on.

Your D series transmission would not work with a B series. I've heard of people doing D2B swaps to mate a B series transmission to a D engine, but not the other way around.

Honestly based off everything you've said so far I don't think the swap is in your best interest. You may just want to rebuild your current engine, possibly add a few bolt-ons. Up to you of course but something to consider.

 

Another vx being destroyed by ignorance.

 

Oh man the VX is such a gem too. Fantastic at what it was designed to do.

Turbo the VX. Probably won't get more than 150hp reliably but it also stays VX. Could probably tune for lean burn but I don't think Hondata had EGR support.

 

Reliability....B series over turbo D series.

MPG...Turbo D series over B series (So this depends on tuning but a good tune and a light foot will give you greater efficiency vs straight na. From my personal experience)

Better MPG... Turbo B series

Power...B series
Transmission Reliability...B series

A non-vtec B20 in an EK coupe is a tad faster than a D16Z6 turbo in an EG @ 12psi proven a week ago between me and a friend.

 

yea I definitely hear what youre saying, 100ish pounds is what a lot of the forums and sites seemed to say that why I went with 100. Thank you for letting me know about the tranny also. I want to do a swap because where I live theres lots of mountains/hills and I have to be at pretty high rpms just to keep going the same speed, usually im around 3800rpms or so on the steep hills and am still loosing speed. Thats why I wanted to do more than bolt ons, on the forums I read most said Id only gain a few horses from bolt ons. most people said 3-8. Also the top end of the engine had work done to it, I have to check exactly what was done because the guy who sold it to me had it done but the engine is in pretty good condition, 118k miles also.

 

Ik its a pretty amazing car, when driving on highways that arent steep like the ones where I live I get pretty good mileage, unfortunately I only get around 31-35 around here. So thats why I want to do a swap. I was thinking of turboing the VX but everyone on the forums said it cant take much hp and it wouldnt be worth it. Id rather turbo the VX but everyones advised me against it thats why I didnt mention it.

 

Keep in mind these are tiny four cylinder engines, not big V8's. 3800RPM isn't all that high, and getting 31-35MPG on the lower end of your averages out of a 30 year old engine is pretty impressive on it's own.

It very much seems like you're mostly interested in maximizing MPG, in which case my advice would be to refresh your VTEC-E engine as needed to make sure it's running in perfect shape, and then optimize other areas of the car:
Better flowing intake/filter
Remove exhaust restrictions
Remove any extra weight if possible
Improve aero and reduce wind drag

 

I would agree, VX with the tall gears and hills kind of sucks. I know that pain.

I also know the pain of a first gen insight without the IMA battery in the hills. 60hp and TALL gears is some how worse than the VX.

 

yea, especially from 2nd to third, they are so far apart. pretty conflicted on what I should do. I definitely want more power, I dont know if ill be happy with just 30 more hp and 10 more ft lbs of tq in the D16z6 or if I should just do a b18c1 swap and get about twice the horse power and 30% more hp. mileage is a concern because my 89 yota pickup gets about 19-20 mpg and I want to be at least getting 25

 

I'm just curious - Why so much concern for MPG? I'm just curious if it's from a cost-savings perspective, because regardless of if you go the B18C swap route or turbo D you'll be spending several thousand dollars.

 

DOHC will usually give you more efficiency over SOHC.

 

A D16Y8 makes 107 ft/lb torque vs a B16A2 making 111ft/lb torque. Closest SOHC to DOHC example I can give.

I will omit the horsepower as horsepower is just torque over time and the B16 revs an additional 1000rpm over the D16...

 

Go to a not VX transmission? Give up a little bit of mpg for far better gear ratios.