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10 Posts
Discussion Starter #1
i was wondering if a d15 block with d16y8 head would make more power than the d16y8 enigne

3,818 Posts
Using a butt dyno, it would be hard to tell that much of a difference. With the mini-me you would have a little bit less displacement but, depending on which headgasket you used, anywhere from 10.0-1 to 10.6-1 compression(based on OEM thicknesses). Stock on a Y8 is 9.6-1.

10 Posts
Discussion Starter #3
so what do you recomend rember i am going to and on more parts now were will if parts for the mini me swap do i by parts for a d15 or d16

3,818 Posts
Depends on what your plans are for the motor. Are you gonna overhaul it completely, like new rings/bearings/seals? Or do you just want to toss a motor in and go from there? If you're planning on a rebuild, do the mini-me. If you just want to just toss a motor in and start bolting stuff onto it, do a Y8.

10 Posts
Discussion Starter #5 (Edited)
i was thinking of th mini me n/a flywheel headers cam stuff like that because the d16 block thati have is bare no oil pan and more i was thinking that the mini me swap would be easyer and the compression is nice out of the mini me
plues i already hae the d15 motor in
and if i do the mini swap what parts would be needed

3,818 Posts

So if I'm reading this right, you have a Civic with a D15 already in it and are trying to decide between just swapping a head on to that motor(making it a mini-me)or swapping in a whole new motor? If that's the case and if your motor in there right now is in good shape, slap a VTEC head on that bitch.

545 Posts
It is just as long as you know what you're doing. you'll also need a 96-00 civic cam gear or that year model adjustable cam gear to set your cam timing right.

3,414 Posts
Maybe this will help with those trying to see what is involved in swapping a D-series head, or use it as good reference material while doing a swap.

Mini-me Compression #'s
Thanks to HondaTuning
and pee_wee

Z6 /Z6 Block - 9.13:1
Z6 /y8 Block - 9.21:1
Z6 /A6 Block - 9.95:1
Z6 / ZC Block - 12.03:1
Z6 / D15 - 10.10:1
Z6 / Y7 - 9.62:1

Y8 / Z6 - 9.45:1
Y8 / Y8 - 9.61:1
Y8 / A6 - 10.33:1
Y8 / ZC - 12.61:1
Y8 / D15 - 10.52:1
Y8 / Y7 - 9.96:1

Threads from our members:
D16Y7/Y8 MINI-ME WRITE UP (56k, maybe not)

This is a write-up of my y7/y8 mini me. done Bauleycivic style, though with less detail.

This swap was performed using a 1996 D16Y8 head which was mated onto a 1997 D16y7 block. I also swapped my pistons and rods for those from an 89-91 D16A6 for more compression.

pictures of my particular y8 head:

What you need to buy:
New coolant and oil
d16y8 head
d16y8 head gasket
new head bolts

1. drain the engine of coolant and engine oil
2. disconnect all coolant hoses, sensors, throttle cable, exhaust manifold and bracing from the y7 head (leave the y7 intake manifold attached--it makes the head easier to lift)
3. remove the spark plug wires and valve cover from the y7 head
4. unbolt the distributor from the head, and lay it aside, it's unnecessary to remove the dizzy from the engine bay
5. remove the 10 head bolts
6. double-check to make sure nothing else is still attached to the head, and then remove it from the block

now make sure the block is nice and clean, and if you are going to replace your internals like me, this is the time to do it, just drop the oil pan, and remove the rod bolts and pop the pistons out of the top of the block.

oh yeah, next time you hear someone talk about the bottom end of a d-series being unstable, take off the oil pan of a y7 and you'll notice a solid piece of aluminum, at least 3 inches wide tying the main caps together. :thumbup:

FIRST MAKE SURE THE #1 CYLINDER IS AT TDC by rotating the crank usign the crank pulley bolt and that the cam is adjusted to straight up position.

1. spray the y8 head gasket with copper spray and put it in position, then replace the two spacers in the block.
2. lay the head on the block carefully, making sure everything goes on smoothly
3. torque the head bolts following the factory sequence
4. reattach all of the various sensors, timing belt, coolant and vacuum lines, and whatnot to the new head.

Also, at this time, replace the P2E ECU with the P2P from the EX trim level civic.

NOTE: we did not change the timing belt on my car as it was in near-perfect condition. that is why i have omitted this information from the write-up

Making it all work: this is the tricky part as there are a wires that will need to be either rerouted, spliced, eliminated, or disregarded.

1. The throttle body is a possible point of difficulty, the easiest way is to use the Y8 throttle body and y8 IACV on the head. In order to do this with the y7 wiring harness, you will need to take two spade connectors and connect them to the two prongs on the male side of the IACV connector, the connect these two wires to the three-wire female plug on the y8 wiring harness, being sure to disregard the orange wire. You will need to swap wires A12 and A14, and then disconnect wire A13 from the plug at the ECU.

2. To wire VTEC, you will either need some pigtails or you can just run two wires through the firewall, to the ECU, one coming from the VTEC solenoid and the positive wire from the VTEC pressure sensor. Be sure to ground the negative side of the VTEC pressure sensitive to somewhere on the chassis. Route the VTEC solenoid wire to socket A8 and the pressure sensor to socket C15 (at the ECU)

3,414 Posts
y8 head/IM on a d15b7 block INSTALL NOTES

Ok, I attempted this swap last weekend and I finished up around 10pm. I tried starting the car, but there were problems (wouldn't start). I got really scared because this is my only car and after fooling around with things for a half-hour I decided to put the b7 head back on. I now know what the problem was and to avoid embarrassement I won't say what it was... But I will give you guys a write-up so you can see what to expect in the swap. I will attempt to do it again sometime later when I have time... ok, here's the write-up:

This is for a y8 head/IM/TB on a 94 civic DX sedan (d15b7).

Ok, credit goes to BaileySi (i think his name was) for providing the initial write up for a z6 head on this block. I will list the differences.

1. The b7 distributor WILL work on the y8 head. No need to use the y8 or z6 distributor... one won't fit, the other has different plugs.

2. The throttle cable won't attach properly onto the manifold unless you modify the small bracket it mounts to. A temporary solution which sort of worked for me was to move the bracket over by one bolt to the left and just use the remaining bolt hole to attach it. A little less secure, but like I said... temporary.

3. Intake temperature sensor... just remove it from your old manifold (on the back near the bottom) and let it hang. I can't guarantee it won't give you a bad idle, but at least it won't throw a code.

4. Purge control solenoid - located on the back/right of the b7 manifold... or on the fuel rail of the y8 manifold. You'll have to use the old one which has a matching plug to your harness and either mount it to the firewall or just let it hang temporarily. Also, since it uses a SMALLER vacuum line than the y8 one does, I ended up connecting it to the cruise control nipple on the back of the manifold. The larger connection on the front of the manifold will have to be plugged.

5. Fuel rail + fuel pressure regulator - these will have to both come from a y8 or y7 manifold. Your b7 or z6 fuel rail won't work. You won't even be able to drill a hole to try to mount it because it has a divit where the hole needs to be.

6. Fuel line to the fuel pressure regulator - you will need to extend this since the FPR will be on the opposite side. Just buy longer hose.

7. Fuel line to the fuel rail (from the fuel filter) - I tried using the one from my engine (b7) and it doesn't fit properly. The cap that goes on the end doesn't screw onto the fuel rail all the way. I ended up using a large washer in between the fuel line fitting and the cap to take up the slack space. This seemed to work as I wasn't getting any leaks when it was primed. I didn't investigate using the y8 or y7 fuel line and cap since I didn't have one.

8. Use your original fuel injectors... y8 fuel injectors have different plugs.

9. Charcoal canister - my car has three connections coming out of it. The canister designed for the y8 head has only two. My guess was to plug up the line that originally went to the b7 throttle body. The y8 throttle body doesn't have this vacuum connection.

10. MAP sensor - not sure if these need to be swapped but they have different numbers printed on them. i swapped mine just to be sure, but either one will fit your harness.

11. Coolant lines - This one I'm unsure about. The b7 intake manifold has one extra coolant fitting that the y8 im doesn't. I wan't sure about what flows where so I was guessing which line to plug up. However, on the y8 head, there is a large coolant port with a smaller port coming out the top of it. This is located near the VTEC solenoid. I decided to try and plug up the small port. Since my car didn't run for a long period of time, I can't be sure that was the right thing to do.

12. The bracket that supports the manifold against the block will no longer fit if you put the y8 manifold on. I had to remove it in order to get the whole head/manifold to seat well on the block. This MIGHT cause some stress issues for longetivity's sake so you might want to look into getting a new bracket machined to support the manifold's weight. However, my setup fit well so there won't be any immediate problems, if any at all.

Finally, just to confirm the original write-up: I used the y8 timing belt. Worked fine. I removed the oil control jet in the d15 block. I had to use new spark plug cables meant for the y8 head. This is all I could remember... so far.

As you can see, figuring out all this is what took me so long (10pm!! good thing we had an outdoor light to plug in). When I couldn't get it working right, I panicked because I needed my car the next day to pick up my girlfriend from the airport.... but, after careful thought, I know what my mistake was, and it wasn't anything I listed above. (It's got to do with spark plug wire order!!! DAMN!!! spilled the beans!!! I'm so ashamed)

If you need any help email me and I'll try to help if I can. Thanks to everyone on this board for answering all my previous questions!

3,414 Posts
[FAQ] D15 SOHC VTEC Mini-Me: Massive Write Up


Additional Links on Mini-Me's:

Welcome to my D15 SOHC VTEC Mini-Me Writeup!
This is a write-up based on a 1992 D16Z6 head being bolted onto a 1993 Civic LX with a D15B7 block. Like Spade’s SOHC Upgrades thread, this is a continual work in progress. If you are thinking about doing a mini-me swap on your 92-95 Civic using a D16Z6 head, then this is the place to be. I will do a complete walkthrough of the mini-me, including a shopping list of parts, tools needed, how to perform the swap, important things to look out for, what to expect when you finish, and ideas for future modifications. These instructions are for 92-95 Civic D15B7 DX, LX mini-me’s, but most of the stuff can be applied to CX’s and VX’s as well. If you have a question about doing a mini-me on a non-OBD I car, you can PM me and I’ll see if I can help. Well…enough already let’s get to it!

1. What the exactly is a “mini-me”?
A “mini-me” is an informal name for a D-Series SOHC VTEC head mated to a D-Series SOHC non-VTEC block. Most mini-me swaps consist of D16Y8 or D16Z6 heads onto USDM D15B, D16A6, or D16Y7 blocks. JDM D15b VTEC heads will work as well.

2. Why should I do a mini-me swap?
I chose to do a mini-me swap after reading up on them and hearing that they put out a fair amount of power for how cheap they are. It is widely believed that this combination, with a thin D16Y8 head gasket, will produce a near 11:1 CR. However, after calculating the compression using the d-series compression calculator, I only came up with 10.1:1. To bump the compression a few more tenths, you can remove the middle layer from the Y8 head gasket. Theoretically, a stock mini-me with a Y8 head gasket should put out about as much power as a D16Z6, give or take a few horses. The raised compression makes up for the difference in displacement.

2. Okay, what parts do I need to buy?
For a Z6 mini-me swap you’ll need four basic things: a D16Z6 cylinder head (including valve cover, distributor, spark plugs, spark plug wires etc), D16Z6 timing belt, D16Y8 head gasket (D16Z6 works well also, but Y8 is a better, metal gasket) and P28 ECU (make sure you get an auto ECU for an auto, manual for manual).

IMPORTANT: Several places on the net and several people on Honda-Tech say that the VX (D15Z1) timing belt is the one to use for this swap because it is for a 1.5L VTEC. THIS IS INCORRECT! When I did the initial head swap, I used a VX timing belt. The VX timing belt was WAY too tight, and whined when the engine was at high rpm. I unfortunately did not discover this until the entire head was assembled. The VX timing belt has 103 teeth, where as the Z6 timing belt has 104 teeth, and the B7 belt 106 teeth. I was finally able to replace the VX timing belt with the Z6 timing belt, and the Z6 timing belt fit much better and didn’t whine. THE D16Z6 timing belt is the correct belt to use with a B7 block / Z6 head combination.

Note also: The D16Z6 and D15B7 spark plug wires are NOT interchangeable. You will need D16Z6 spark plug wires with this swap. Also, 96-00 Civic HX spark plugs are a bit colder than the Z6 and will work better with the higher compression.

You can use your stock intake and exhaust manifolds with the mini-me. All d-series manifolds are interchangeable. However, both the D16Z6 intake manifold and header flow much better than the D15’s…so if you can pick them up for a real cheap price, then definitely go for it. In addition to the main things, you’ll need little things, coolant and wire (to wire the VTEC solenoid and oil pressure to the ECU).

I however, wanted to make sure that the swap ran perfectly once I got it running so I picked up a few general maintenance things as well, such as a new distributor cap and rotor, new water pump, new spark plug wires, and a new valve cover gasket.

List of Parts:
D16Z6 Cylinder Head (Including distributor cap, valve cover, plugs/wires, VTEC solenoid, etc)
D16Z6 or D16Y8 Head Gasket
D16Z6 Timing Belt
Wire and plug for VTEC oil pressure switch

D16Z6 Intake Manifold
D16Z6 Exhaust Manifold
*If you remove your manifolds, make sure you get new gaskets

Water Pump (for the block you are using)
Spark Plugs (HX D16Y5)
Spark Plug Wires
Valve Cover Gasket
Distributor cap and rotor

I spent about $550 total when all was said and done. I paid $200 for the head, and $85 for the ECU. Random stuff kept adding up after that. $550 is comparable to a full Z6 swap, but remember this included a new timing belt, head gasket, etc.

3. What tools will I need to do the job?
Well, 95% of the job can be done with a 3/8 inch ratchet, 10-19mm sockets, and a set of screwdrivers. However, you will need a torque wrench so that you can torque the head bolts down correctly, and you will also need access to an air wrench when you do your timing belt to get the crank pulley off. You will also need wire cutters, and some electrical tape for the wiring part.

3,414 Posts
4. Okay, I got all of the parts and tools, now how do I swap the heads?

Alright first what you’re gonna need to do is remove the cylinder head.

Here are the step by step instructions on how to take your head off (Taken from helms. I recommend you have the actual manual in front of you because it includes detailed pictures and diagrams):

1. Disconnect the negative terminal from the battery.

2. Drain the coolant.

3. Relieve fuel pressure (take the gas cap off)

4. Remove the air flow tube (intake)

5. Remove the fuel feed hose and charcoal canister hose from the intake manifold.

6. Remove the throttle cable at the throttle body.

7. Remove the throttle control cable from the throttle body (A/T only).

8. Remove the fuel return hose and brake booster vacuum hose.

9. Remove the engine wire harness connectors and wire harness clamps from the cylinder head and intake manifold (Basically any hose or plug that’s connected to the intake manifold or head, needs to come off)

10. Disconnect spark plug wires at spark plugs and remove them from the distributor.

11. Remove the engine ground cable on the cylinder head cover.

12. Remove the power steering belt and pump (Do NOT disconnect the hoses)

13. Remove the power steering bracket (4 bolts)

14. Remove the emission vacuum hoses and water bypass hoses from intake manifold assembly (included in step 9)

15. Remove the radiator upper hose and heater hose from the cylinder head (included in step 9)

16. Remove the water bypass hose from the thermostat housing.

17. Remove the intake manifold bracket.

18. Remove the self locking nuts and disconnect the exhaust manifold and exhaust pipe A.

19. Remove the exhaust manifold bracket.

20. Remove the PCV hose, then remove the cylinder head cover.

21. Remove the timing belt upper cover.

22. Loosen the timing belt adjusting bolt 180 degrees to release the belt tension.

23. Push the tensioner to release tension from the timing belt, then retighten the adjusting bolt.

24. Remove the belt from the cam pulley (gear)

25. Remove the cylinder head bolts, then remove the cylinder head (loosen bolts starting from the outside, then coming in).

VERY IMPORTANT: If you have a D15 block (or any D-series block with an oil jet for that matter), you need to make sure that you remove the oil jet between cylinders 2 and 3 when you do this swap. If you don’t, you won’t have VTEC. I forgot to pull the oil jet out the first time. You won’t get a code, your ECU will say your solenoid is fine and everything is working great but VTEC will not actually engage. Make sure you remove the oil jet. I took a screw, screwed it into the oil jet, and then pulled it out with a pair of pliers.

After you’ve pulled the oil jet, you’ll need to sand down the block surface so that no gasket is left caked on the block. (You won’t have to worry about this anymore because hopefully you’ll be using a Y8 metal gasket). If you get shavings in the cylinders, then fill the cylinders with warm soapy water and float the shavings out. You’ll do this by turning the crank over a few times with a 17mm until all the water is out. Make sure that there is NO liquid in the cylinders or head bolt holes when you put the head back on (If there is, you can crack your block when you torque down the head bolts). If you are using the manifolds from your stock motor, all you’ll need to do is unbolt your intake manifold (with throttle body) off of your old head so that you are ready to put it on the Z6 head. It’s only 8 bolts.

Now, let’s put your new head on (Taken from helms. I recommend you have the actual manual in front of you because it includes detailed pictures and diagrams):


-You can reuse your D15B7 head bolts with the D16Z6 swap…they are the same size

-Always use a new head gasket

-If you are using your old intake manifold with the new head, make sure you use a new intake manifold gasket, same goes for throttle body. If you removed it, you need a new gasket.

-Cylinder head and engine block surface must be clean (no water or dirt…even in the head bolt holes)

-Turn the crankshaft so that No. 1 piston is at TDC.

1. Install the intake manifold and tighten the nuts in a criss-cross pattern in 2 or 3 steps, beginning with the inner nuts.

2. Install the exhaust manifold and tighten the nuts in a criss-cross pattern in 2 or 3 steps, beginning with the inner nut.

3. Install the exhaust manifold bracket.

4. Install two dowel pins, head gasket, and cylinder head

-Apply clean engine oil on the bolt threads and washer contact surface

-Always use a new cylinder head gasket

-Turn the cam pulley to TDC before installing

5. Install the bolts that secure the intake manifold to its bracket but do not tighten them yet (optional, I decided not to do this because the intake manifold bracket is a bitch to get to)

6. Tighten the cylinder head bolts in two steps, working your way from the inside bolts to the outside bolts.

-Step 1: 22 lb ft

-Step 2: 53 lb ft

7. Install the exhaust pipe A on the exhaust manifold.

8. Tighten the bolts for intake manifold bracket (again, optional)

9. Install the exhaust pipe A on its bracket

10. After the installation, check that all the tubes, hoses, and connectors are installed correctly.

11. Adjust the valve timing.

12. Apply liquid gasket to the head mating surface of the number 1 and number 5 or number 6 cam holder then install the cylinder head cover (you can neglect this because you need to leave it off for the timing belt install)

13. Install air intake.

14. Fill radiator with coolant.

Alright, we’re getting there. Now all we have left to do is the timing belt, and the VTEC wiring.

COMPLETE timing belt and water pump replacement thread by Poison, GREAT info:

Lets do the timing belt first (Taken from helms. I recommend you have the actual manual in front of you because it includes detailed pictures and diagrams):

1. Remove the splash shield

2. Remove the power steering pump (should already be done)

3. Remove the A/C compressor adjust pulley with bracket and the belt (with A/C), then remove the alternator belt.

4. Remove the P/S bracket (should already be done)

5. Loosen the alternator adjusting bolt and pivot nut, then remove the belt.

6. Remove the cruise control actuator and the P/S tank bracket.

7. Remove the engine support nuts. Loosen the mount bolt and pivot the engine side mount rubber out of the way.

8. Remove the cylinder head cover (should already be done).

9. Remove the timing belt upper cover (should already be done).

10. Remove the special bolt and crankshaft pulley (you NEED an air gun for this).

11. Remove the timing belt lower cover.

12. Loosen the timing belt adjusting bolt 180 degrees to release the belt tension (should already be done).

13. Push the tensioner to release tension from the belt, then retighten the adjusting bolt.

14. Remove the timing belt from the pulleys.

I recommend that since you are replacing your timing belt, you go ahead and replace the water pump as well. It is not that expensive, and is only a few bolts. If the water pump fails, you can kiss your motor goodbye so it’s a good thing to get.

3,414 Posts
Okay, now that you’ve taken the old timing belt off (and hopefully put a new water pump in), lets put the new timing belt in (Taken from helms. I recommend you have the actual manual in front of you because it includes detailed pictures and diagrams):

1. Install the timing belt in the reverse order of removal; only key points described here.

2. Position the crankshaft and cam pulleys at TDC.

A. Set the crankshaft so that the No. 1 piston is at TDC (top dead center).

NOTE: Align the groove on the teeth side of the timing belt drive pulley to the lower arrow pointer on the oil pump.

B. Align the TDC marks on the cam pulley with the pointer on the back cover.

3. Install the timing belt.

4. Loosen the adjusting bolt, and retighten it after tensioning the belt.

5. Rotate the crankshaft (w/ 17mm socket) about 4 or 6 turns clockwise so that the belt may fit in the position on the pulleys.

6. Adjust the timing belt tension.

7. Check the crankshaft pulley and the cam pulley at TDC.

8. If the cam pulley is not positioned at TDC, remove the timing belt and adjust the positioning.

Make sure you adjust the tension the alternator and A/C belts, as well as the power steering belt. Look over everything and make sure it all looks good, because you’re almost done.

5. I’m done swapping the heads, now how do I make my VTEC work?

The P28 ECU plugs right in, you all you’ll need to do is wire the VTEC up. First, you’ll need to get an engine plug from a junkyard for the VTEC solenoid oil pressure.

You’ll need to run the blue wire (or whichever color is from the plug) to pin D6, and then run the black ground wire from the plug to anywhere on the motor. You then need to run the green wire from the VTEC solenoid to pin A4.

THAT’S IT! YOU’RE FINISHED! Make sure you’re not throwing any CEL’s, if you are, go back and check your work.

6. How much faster will my car be once it is done?

Well, my car definitely felt much better overall. The lower end will be a bit torquier, and your car will pull much better in the higher RPM’s (5000+). I feel the most difference on the highway, having the extra HP is very nice when you need to merge. I don’t have any quarter mile times from my mini-me, but I will post them as soon as I run it. The one downfall to a mini-me is the long transmission. The DX transmission is much longer than the EX, and the VX/CX is even worse. I did some calculations, at 7200 RPM here are your shift points with respective transmissions (using 195/50/15 tires, stock tire size):

CX/VX Transmission:

46 - 85 - 140 - 175

DX/LX Transmission:

37 - 68 - 102 - 132

EX/Si Transmission:

35 - 60 - 91 - 126

The gear ratios were taken from Mista Bone's tranny page. Emerika stated that the EX transmission shaved 7 tenths of a second off of his quarter mile time in his hatchback, you DEFINITELY want to get the EX transmission

7. The mini-me is nice, but I want to make it even faster. What mods should I consider?

The number one modification you should do is the EX transmission. You can pick one up in the Honda-Tech classifieds or in a junkyard for about $200 bucks. They are worth their weight in gold. The usual intake/header/exhaust combination works very well. Exospeed, ZEX, and Skunk2 make very good SOHC VTEC camshafts that will add a good bit of power as well. If you want to take it even farther, you can use D16A1 Integra pistons (P29) that will put your compression way into the 12’s.

For more info on SOHC upgrades, click here -

Shoutouts to:

Sander and Steve of Mixed Motorsports for all of their help :thumbup:

MistaBone for knowing everything and helping me whenever I had a question

Spade for all of his knowledge

Poison for his awesome timing belt / water pump writeup
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