D15b1 sohc vtec Swap Guide

SuperSleeper · 02-06-2005, 02:25 PM

Due to the amount of threads that are being started regarding the D15B1 SOHC VTEC swap and whats involved I’m going to go step by step over the process it took me to get mine up and running. I’m going to try and be as complete as possible but I might leave something out so bear with me.

First and foremost you do NOT have to convert over to OBD1 for this swap. You can if you want but it is not necessary. This is a very simple plug-and-play swap that can be done in your garage over the weekend. This is a how-to for the si and hf models because I have no idea how to convert the dx. I will start from the stand point that your old motor is already out of the car and the tranny already taken off motor.

What you need off the old motor:
Flywheel/clutch/pressure plate(‘88 Si only)
Distributor
Injectors
Fuel pressure regulator
Driver side motor mount
Alternator(only if the new motor doesn’t have one)
Crank pulley(only if you have to use the alt. off the old motor)
Exhaust manifold(any aftermarket d-series header will work)
The sensor on the back/center of the block(take bolt out of the back of the new block and put the sensor there)
Engine harness

Before you transfer the motor mount it needs to be modified. The front side of the mount is going to be too close to the timing belt and the belt will rub on it when the motor is running. The front side needs to be shaven down approx. 1/2”-3/4” for the timing belt to clear it. I drove around like this for about a month before I had time to pull it back off and modify it. Do it while its off cause it’s a pain in the ass if you have to pull it off later or even worse if the timing belt breaks. I actually tightened my belt also at the same time just to make sure.

Once you’ve transferred all that to the new motor and bolted the tranny up you can drop the motor in. I chose to go in from the bottom which requires taking off the front crossmember(4 bolts at the chassis and 4 more at the suspension, easy). This way you don’t need an engine hoist and I personally think it was easier. Bolt everything up and start to plug your engine harness back into the main harness.

When you do this your not going to use the MAP sensor on the firewall. The MAP sensor wires will need to be extended approx. 4-6 inches. After extending the wires plug into the MAP sensor on top of the throttle body. Plug into the IAC on the intake manifold as well as the TPS. Next is the Air Intake Temp which is located on the back of the manifold now instead of the side of the manifold. These wires will need to be lengthened 4-6 inches also. That’s all the modifications for the engine harness, everything else will plug directly in without a problem. There wont be a plug on the harness for the vtec stuff or the coolant sensor on the thermostat neck, so dont worry when you come across those.

The fuel rail from the new motor MUST be used but the injectors and fpr from the old motor need to be swapped out. The reason is because the injectors on the new motor wont work with the engine harness. Both sets are the same cc’s so just make it easy on yourself and swap them out. And run the old fpr, you’ll see why.

Once you have all the fuel supply secure move over to the distributor. This is going to require a dremel tool. You need to make the top hole a lot wider than it already is. If you notice the rest of the holes wont match up and if you plan on using them you will need to make special brackets. I run one distributor bolt on top and it works fine but I do have a SMALL oil leak. Set distributor as far back towards the firewall as possible, you may need to modify the hole more once the motor is started and the timing is being set.

Once the distributor is in place you will need to go buy plug wires for a 92-95 civic si(only if the new motor didn’t come with them) or a d16z6. I think any sohc vtec plug wires will work, but don’t quote me on that.

I used a d16z6 lower radiator hose and a modified crx si upper hose. Its not to difficult to figure out.

The car should be ready to start now. Make sure the fluids are ok and go for it. Also make sure you have all the grounds in the correct places, I didn’t have the tranny to firewall connected and it took me a good hour to figure out what the hell was wrong. Start her up and shoot timing. I set mine at 16 degrees and she runs perfect, idles perfect and has no CEL’s.

That’s how to get it running, now you need vtec. I bought a PR3 Integra ecu. I chose that ecu because it plugs right in, its OBD0, and of course, its got vtec. You will need to wire up vtec which is very simple but I haven’t done it yet so I couldn’t tell you exactly how its done. My ecu will be here on the 8th and once that’s installed and vtec is wired up I will update this.

I think that’s all. It was a shortened version of the actual process but it goes over the major stuff that you'll run into. If I can think of anything else or if anyone has anything to add feel free to comment(no flames, just trying to answer a lot of questions). I felt like this swap was becoming very common and theres been a lot more questions about it lately.

SuperSleeper · 02-06-2005, 02:34 PM

Just a side note, I didnt do this swap cause I thought it would turn my 17 sec econo car into a corvette eating econo rocket. I had headgasket and timing belt issues with the stock motor and instead of getting the head redone and doing a new headgasket I figured this would be a much more economical choice for the time being. I do have future plans for a DOHC vtec of some sort but I need this as my daily driver. As of right now I have probably $600 into the swap and that includes a new clutch, axles, motor, ecu and any misc. nut/bolts/beer.

Moon Ill · 02-06-2005, 10:35 PM

so give a general price of how much everything cost over all... even if its a ballpark estimate.

and remeber, overestimate.

SuperSleeper · 02-07-2005, 06:29 AM

$200-motor
$100-exedy clutch(ebay)
$125-header
$80-axles
$80-ecu
$50-misc stuff
$635 total

Some of you may not need axles, header, or clutch but I always think its a good idea to replace them while their out. That was at my prices too so if you want an overestimate I would have to say around $800 for everything. Now some might say that it seems kinda high but realize this; its around $1500 for a COMPLETE b16 swap. That usually doesnt include new axles, new clutch, an aftermarket header, the correct shift linkage, etc. There are some good deals out there but you have to look for them.

kain_03 · 02-07-2005, 07:02 AM

can a guy use the zc distributor? I also heard to convert the d15b to mpfi you use the si distributor, intake manifold? and what cams are good for these engines? also will the flywheel bolt up from a 91 crx si? and also would the zc intake manifold and all of that bolt up to the d15b to convert to mpfi? what car do you get the timing belt from also? thanks

DeathIsCertain · 02-07-2005, 10:17 AM

very good thread IMO thanks man

DeathIsCertain · 02-07-2005, 12:00 PM

u get the rep

SuperSleeper · 02-07-2005, 07:45 PM

Quote:

Originally Posted by kain_03

can a guy use the zc distributor? I also heard to convert the d15b to mpfi you use the si distributor, intake manifold? and what cams are good for these engines? also will the flywheel bolt up from a 91 crx si? and also would the zc intake manifold and all of that bolt up to the d15b to convert to mpfi? what car do you get the timing belt from also? thanks

I dont know much about zc stuff so I couldnt tell you whether or not the distributor will work. Try it and tell us. Let us know if the zc manifold fits too.

Yes the si dist. has to be used but not the intake mani. The only reason people use the intake mani is because its assumed that the throttle body from the si needs to be used, which isnt true, and the si throttle body wont fit on the d15, hence the swapping of the manifolds. The one that came with the d15b1 works fine. Also the fuel rail/injectors/fpr wont fit on the d15 so people just swapout the complete intake manifold/throttle body. There's nothing wrong with doin it that way, it works just the same, but make sure you've got a new intake manifold gasket before you go swapping that stuff. Doing it the way I did you wont have to buy ANY gaskets.

I've heard of Delta's, Skunk2's and Venom's doing really well for cam upgrades but you may want to do a search on that cause I know theres a crapload of info here on d-series cams.

Yes the flywheel will bolt up but its not needed. The '88 Si had a smaller flywheel than the other si's but all you would need is the clutch/pressure plate ass'y from yours.

The timing belt should be the same as a d16z6 because deck height and head configuration is the same as the d15b1. Same with the water pump/tb tensioner.

SuperSleeper · 02-07-2005, 07:47 PM

Quote:

Originally Posted by DeathIsCertain

very good thread IMO thanks man

Thanks, I just wanted to clear up most(if not all)the questions that sho has been getting lately.

kain_03 · 02-08-2005, 06:55 AM

thanks so much man for all the info, its been hard to trackdown the right info here on the net. how much of a difference does a vtec controller make for tuning and performance, and where do all the vtec wires and such plug to, do they all meet up to the ecu if you put a vtec ecu in and what differences are there between the ecu's available that plug into the obdo, if theres a huge difference between the obdo ones and the obd1 which are better because I want to crank as much out of this little guy as I can when I drop it in, time and tools are no biggie because I work for a ford honda mistsubishi dealer

thanks for all the info so far man. peace

Moon Ill · 02-16-2005, 08:20 PM

STICKY

sonictronic · 02-16-2005, 10:54 PM

Quote:

Originally Posted by SuperSleeper

The timing belt should be the same as a d16z6 because deck height and head configuration is the same as the d15b1. Same with the water pump/tb tensioner.

We tried a d16z6 timing belt, it is about 1 inch too long and does not tighten up very well. However if you buy the belt for a D15Z1 (VX) motor it will be the perfect length for the D15B. All the other stuff, water pump and such is the same as the Z6 tho.

drummingpariah · 01-26-2006, 09:28 PM

STICKY STICKY STICKY this is exactly what i'd been looking for for about 3 hours now.

SuperSleeper · 01-26-2006, 10:15 PM

I havent seen this thread in awhile but I'll tell everyone that the car is still running strong with close to 25,000 miles in the past year(I drive allday for work). I think the tranny is ready to go but everything I did as far as the swap is still holding up. Glad I could help.

drummingpariah · 01-27-2006, 06:16 AM

well that is good news, and may sway me over to the vtec side. it's a toss-up between the d16a8 and d16z6 right now. pretty similar, but for daily driving the d16z6 may end up being a better buy. however, ease of swap may not be so simple, as i'd really like to get it done right the first time and this whole vtec controller is always a hot topic of debate.