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D18Y8 engine build

325K views 533 replies 123 participants last post by  yb_sonny16 
#1 · (Edited)
My D18 build…

Warning: I wrote up a lot of shit. I know that some of you might be interested in the details. Skip to the build summary and pix if you can't bear to read it all.

This is a thread about building a 1.8l D16Y8 aka the D18 and installing into my 97 Hatch. While I’m still in the middle of this build, I thought I’d get started documenting what I’m doing and share my thought process behind it. Of course this is an open forum so all comments and question are welcome.

The Goal

My goal with this project is not to impress anyone with big HP numbers, sub 14 second ¼ mile times, or Mustang kill stories. My goal is to build an engine for a daily driver that is interesting and fun for me. I’m not trying to be “different” but rather I wanted to do a build that had new or at least uncommon challenges. Swapping in a bigger engine or slapping on a turbo kit is not interesting for me. Getting the most power for the least dollars is not important to me either. I’m mostly interested in the learning process. And I also like the idea of building what you have.

Still, I do have some design objectives. I will be using a D16 block and build it to make my daily commute more fun. The commute consists of winding hilly undivided “scenic” highways that travel through the CT country side. The max speed limit is 45mph which means I’ll get up to 60 in some areas especially when passing slower cars. Quick acceleration from a standstill or from slow speeds (without doing a launch) is important to me. Therefore, the overall goal is to maximize the low to mid-range powerband.

No replacement for displacement

OK, so I’ve chosen to increase low end torque by reliably maximizing the displacement of the D16. This basically means I need to increase the bore and stroke. Now I’ve read on various forums of 81mm bored d-series motors but those engines apparently didn’t last nor could I find a way to do this reliably. I felt the safest approach to increase bore is to sleeve the block and bore to 78mm. Darton recommends this as a maximum bore for their d-series iron MID sleeves. So the build includes Darton open deck MID sleeves. So that’s pretty simple (but expensive).

The most common way to stroke the D16 is to swap in a D17 crank. There are a few different ways to go about this part of the build. The problem with adding the D17 crank is that you need thinner rods to fit between the journals and you need to deal with the D17’s larger snout. You can choose between stock D17 rods, aftermarket D17 rods, B18C rods, or custom rods. Custom rods might be something to consider if you want to use standard D16 pistons. If you use standard 137mm rods with the D17 crank the longer stroke will clear the deck. So in this case you need to use pistons with the same (27mm) compression height as the D17. However, if you wanted to use D16 pistons that have a higher (29.5mm) compression height you could get custom shorter rods (134mm). The tradeoff is that 78mm D16 pistons are readily available but the R/S ratio (1.42) would be even less favorable than the stock D17 (1.45) but not by a whole lot. As a comparison the D16 R/S is 1.52. More on R/S ratio later.

I chose to go with Crower maxi-lite I-beam D17 rods. At the time there were no other reasonable aftermarket options. They are a proven product and lighter than H beam rods (i.e. Eagle). OEM D17 rods have been known to hold up past 200 hp but as you’ll see in the pics they look really weak and I thought it better to build in some strength to the rotating assembly in case I decide to increase boost later. They are not cheap. Using B18C (137.9mm) rods is possible but some machining is required to narrow the BE so I thought it better to avoid possible mistakes made by a machinist or risk bearing fitment issues that could lead to spun bearings. B18C rods not only need the BE narrowed they also need custom piston work to deal with the 21mm PE diameter. The cost savings could get eaten up by the cost of machining. This might be a good option if you can machine them yourself.

The pistons used in my build are custom 78mm Arias D17-like pistons designed by Nick Arias III from Atomic Speedware. The 6.22cc dish gives us a C/R of about 10.2:1 when installed in a stock D16Y8 with a .030” head gasket. The deck clearance is calculated to be -.032”. One thing that Nick changed was to move the oil ring down a bit. Doing this intersected the pin hole so buttons were used to form a continuation of the ring land through the pin hole. I didn’t get a pic of this, sorry! More on the C/R later.

Now back to the crank snout… The D17 crank drops right into the D16Y8 block. The end caps of the D17 and D16Y8 look identical. The oil pumps look identical except for 2 things; the D17 has no dipstick hole and the oil seal opening is bigger. The dipstick problem can be avoided altogether when using a D16Z6 block since it’s located on the exhaust side of the block. Another option is to machine a dipstick hole in the D17 oil pump and use that pump (the D16Y8 oil pan bolts up to it fine). I chose to machine the crank so that a D16Y8 pump could be used – specifically a Toga high volume pump. You could have the D17 pump ported and shimmed to add oil pressure but I chose to go with an off-the-shelf product in the hopes of avoiding mistakes in the machine work.

In addition, the diameter of the very end of the D17 crank snout is larger than the D16Y8. So the crank pulley and timing gear will not fit. You could use the D17 timing gear and pulley or have the D16Y8 gear and pulley machined. I chose to machine the snout so that I could use the stock D16Y8 parts and avoid any possible mechanical timing issues. I could use an aftermarket D16Y8 pulley if I chose (I know - at great risk to my bearings). The D17 crank pulley has more ribs on it so you’d have to get a special alternator pulley to match it, etc. So besides installing sleeves the only special machine work so far was done to the crank snout. I provided my machinist with a Y8 crank as a template. He also cleaned and polished the crank journals.

There were 2 other things that needed machining. Because larger aftermarket I-beam rods were used, the block needed notching as usually is the case. Secondly, the main cap had to be notched to accommodate the more extreme rod swing. See the pics.

Still I want even more torque

The plan is to build this motor N/A for the time being and get it running reliably. This coming winter I plan on adding a JRSC. This is one reason that the C/R of 10.2:1 was chosen. It is believed to be a good ratio for this blower. It is also relatively close to the stock compression of 9.6:1. I need to have the car pass an emission inspection that consists of an ODB2 scan for CELs. So I need to be able to run the engine briefly using the stock ECU. This is another reason I stuck with the D16Y8 – since the car is a 97 it needs to run ODB2 once every 2 years for this test. I didn’t want to dick around with older blocks with newer heads, mess with wiring, etc.

More on R/S ratios

OK I promised I’d touch on this again. The so-called poor geometry of Civic engines has been discussed with great conviction on this and other forums. I’m not a mechanical engineer but I am an engineer by trade so I see most design choices as having positive and negative trade-offs as opposed to black and white absolutes. In other words, some would say that the D17 geometry sucks because you can’t rev it so it ain’t any good. That’s nice but one of the positive trade-offs is that it has good low end torque. Good for me cause that’s what I want. What about excessive side-loading and higher piston acceleration speeds? Is side loading a problem in stock D16s? How much worse is it in a D17? I couldn’t find a way to calculate absolute side load force values (there are too many variables) but I did find a way to calculate the percentage increase in maximum side loading. You can calculate a “normalized” force generated by the combustion that gets directed to the cylinder wall at various crank angles. The maximum force occurs at about 75* from TDC. The D16Y8 calculated out to a normalized side wall force of .34 while the D17 came out to .35. That’s a 3% increase in side wall loading. This seems like a minimal increase to me so I’m not worried. Apparantly Honda wasn;t worried either when they built millions of D17s. For extra protection I also had the piston skirts coated. (If anyone’s interested on more details I can post up links to detailed discussions along with the spread sheet that does the calculations.)

Where will all this lead? How much HP? How many ft-lbs? Whatever it is – it is.

Continued...
 
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#2 ·
Fuel components

Now remember I’m gonna be running this N/A for now so I think I should be ok with a stock fuel pump and injectors. I saw that most B18s use 240cc injectors so I’m thinking I’ll be ok with mine. I did add an AEM fuel rail and FPR mostly for bling. I realize the rail isn’t necessary but the FPR might come in handy especially if I need to turn up the pressure when running my stock ECU at the emissions station.

Engine Management

I’m using a P28 Hondata S300 (from Xenocron) and PLX SM-AFR WB O2 sensor. I installed this stuff in the car a couple of months back and practiced street tuning on the existing Y7/Y8 mini-me setup. I should be able to get a decent tune from 0-4k RPM that will get me to Xenocron in NJ for a real tune. The S300 seems like a decent setup. I like the simple setup of a laptop and ECU, ease of data logging, and instant update capability as opposed to using an emulator and burner. The S300 support seems ok although I have my issues with them and also certain issues with the software (I’ll spare you for now.)

Existing mods

The existing engine mods on the car are:


Mild PnP head
ARP head studs
Fake J’s Racing (Whale Penis) intake
Innovative mounts (street)
EX tranny
Quaife LSD
Competition Clutch stage 2 clutch and 12lb flywheel
AEM fuel rail
AEM FPR
PLX SM-AFR WB O2 sensor
Hondata S300
Y8 TB, IM, and injectors
RS*R Ex-mag cat back

Summary of Mods going into this build

Custom 78mm Arias pistons
Crower maxi-lite D17 I-beam rods
ACL race bearings
78mm Cometic head gasket
D17 polished and machined crankshaft
Toga high volume fuel pump
AEM Tru-time cam gear
Hondata IM gasket
Oil filter sandwich
Autometer Cobalt electric oil pressure gauge
Marshall liquid filled fuel rail mounted pressure gauge

The future

As I mentioned, the motor will be boosted using a blower with probably no more than 10lb of boost. Another reason I machined the crank snout end to D16Y8 size was to be able to use JRSC pulleys. Another near future mod will be a 4-2-1 header. I already have a 2.26” RS*R Ex-mag cat back but I still have the D16Y7 stock header with integrated cat. It’s embarrassing, I know. It’s even cracked and looks like shit. It didn’t make the budget. The head already has a mild PnP and was rebuilt with new valves about 15k miles ago. So in the future I’d add some kind of cam that might best benefit my setup. I haven’t looked into this much but maybe the Crower Stage 2 turbo cam. It might make sense to un-shroud the valves now that the bore is bigger. Another option might be to use oversize valves. The fuel pump and injectors will probably get upgraded when the blower goes on.

OK, that’s enough background and discussion. Let’s get to the pics and progress updates!
 
#3 ·
Parts comparison

First off we have the OEM Y8 piston on the top and the D17 piston on the bottom. It's a little hard to see the compression height difference but notice that the oil ring land is closer to the pin hole on the D17. Nick liked the idea of moving it even further down and it actually intersected the hole. Continuation of the ring land was accomplished through the use of a button.




OEM D17 rods vs Crower I-Beams. I have it in my notes that the Crowers weigh the same as OEM Y8 rods but I’m not sure where I got that. I must have read the specs somewhere. I couldn’t see using these wimpy rods in my build even though it would probably be ok.



Here’s a comparison of the D16 and D17 rod end caps that shows that the D17 is narrower. If I chose to use B18C rods I wasn't sure which bearings to use or how well they'd fit or last.


 
#4 · (Edited)
More parts

D17 (on left) vs D16 (on right) crank. It’s hard to see the difference in stroke here but you can see the difference in rod journal width. According to my bathroom scale they both weigh exactly 30 lbs.



But you can see the different snout sizes.




This pic shows the D17 and D16Y8 end caps are seemingly identical. They both fit the Y8 and either pan bolts up to it.

 
#5 · (Edited)
Aha! The oil pumps are the same! Wrong. Look close and you’ll see a hole for the dip stick on the D16 and a larger opening for the crank seal on the D17. Other than that either one will bolt up to the block and either oil pickup and oil pan will bolt up.



Even though it looks like the Y8 pickup is longer than the D17 – either one will bolt up to the pump. The D17 has a shorter tube but the overall length is the same because the pickup mounting brackets are angled. This means you have to match the oil pan to the pickup. The sump area on the D16 is closer to the front of the engine. I wonder why Honda moved it back towards the middle of the engine. It's closer to the drain area so maybe there's more oil there.




The D17A1 crank pulley only has 2 sets of grooves. I'm guessing the 6 groove drives the alternator and the A/C and the smaller 4 groove drives the P/S. IN comparison the Y7/Y8 pulley has 3 sets of 4 grooves. I'll be running an alternator (of course) and A/C but no P/S. Eventually I might have that part of the pulley ground off. So apparantly you can use the D17 pulley with the D17 crank in the D16 thereby avoiding and modifications to the crank snout (if you also use the D17 pump).



I'll add in a comparison of the oil pans once I get the Y7 pan off the old block.

My next post will start to show the progress of the build.
 
#8 ·
In for legendary build... I've been thinking about the D18 for a couple months now, clearly it's been on your mind a bit longer. ;)

I think a full out N/A build would scare a lot of people... no way to tell it's a 1.8L from the outside.
 
#9 ·
Nice write up.

I am building a D18 with mostly the same parts with the exception of the D17 pump (ported and prepped by Endyn), 78mm Rollerwave 9:1 pistons with ceramic top and skirt coatings (again by Endyn), and a D17 crank pulley. I'll be boosting with 7psi to start, going to 12psi later.

It gets installed in 3 weeks!
 
#10 ·
//subscribed...this will be interesting to see what comes of it...

GREAT job so far :TU:
 
#11 · (Edited)
New parts

^^ Thanks pearl for jumping in the thread. He and I have been throwing PMs back and forth about our D18 builds. I'm not sure which one of us really wants to be the first to turn the key. He is doing some real cool stuff with his build. I doubt I'll be done in 3 weeks though so he may be first.

Ok, flash back to uh, November 2007 when I contacted Nick Arias III at Atomic Speedware and began the piston design. Nick seemed like a good guy to work with. He took the time to listen to my plans and really seemed interested and knowledgeable about Honda motors. I got the impression that he's been at this a long time. He ordered the rods from Crower and sent the custom design to Arias Pistons. Then finally in late January 2008 the rods and pistons arrived...



 
#13 ·
wow, i cant imagine what this is gonna do with a JRSC off the line. Thats just a scary thought. Subscribed to watch this come together
 
#14 ·
The crank saga

So armed with my hot pistons and rods, I loaded up the mini van with my Y8 block, Y8 crank, Y8 oil pump, Y8 crank pulley, etc, and of course the D17 crank and headed out to see Ken Carlson at Larry's Machine Shop in Stonington, CT. I brought along both cranks so that the Y8 coiuld be used as a template for machining the snout of the D17. Once the crank was machined Ken can check the fitment of the oil pump and pulley.

Ken has quite a bit of experience sleeving Honda blocks. Some time ago he was associated with a shop in another location here in CT called Custom Design Performance http://www.cdpautomachine.com/. You can see the sleeve installation process he uses on this page.

Anyways, long story short, Ken mic'ed the D17 crank and found that the #1 rod journal was out of round. Now supposedly the donor engine for the crank had only 28k miles on it. I got it locally from a guy who bought it as a replacement engine from a junk yard for his son's 7th gen Civic. Turns out his son wrecked the car before they could swap it in so then I come along and pick it up for $300. After parting out the rest of the engine, I probably ended up with a $50 crank that was scrap.

As luck would have it I found another engine for $165 with 5k miles at a junk yard in Yonkers, NY. Now this engine was real clean and the crank checked out fine. After parting out this motor (so far) I basically have a free crank but a few lost weeks of time. But in the mean time the sleeves were ordered and installed. Now we had to wait for the crank to get machined (and the crankshaft guy was backed up).

Now the big plan was to get this build done in the winter while there's not much going on outside. Plus it keeps the Civic out of the winter weather. So to keep busy I put a new cat and exhaust in the MiniVan and upgraded the suspension in the CRV that the Mrs drives. Finally spring was coming so I got busy with tuning. I bought the Hondata S300 and PLX WB O2 sensor, hooked them up, and started tuning the existing motor (Y7/Y8 mini-me). This effort was also problematic as the WB gauge fried out after using it for not even 10 min. Ten days later PLX sent me another at no charge and it's still working - go figure.

So as the tulips were starting to sprout, I get a call from Ken telling me that the crank is done, the block is assembled, and to bring a big check. I make yet another trip to Larry's with check in hand and bring the block home. It looks so nice, I want to just fill it up with beer and drink out of it.


 
#25 ·
Thanks

Thank you all for the kind remarks. Just to set the record straight, I don't really think I've invented this combo. There are a few other stroked D16s out there but they are rare. 78mm D16 are out there as well but also rare. As we all know Pearl's build is essentially the same as mine but with some interesting variations. Unfortunately we won't be able to learn from each other's mistakes since we'll be making them at about the same time. ;-)

I am much further along than the thread leads you to believe. It will take me a few days of nightly updates to get current.
 
#26 ·
I am much further along than the thread leads you to believe. It will take me a few days of nightly updates to get current.
well if anyone has been paying attention to your posts when a stroked d16 comes up, they would know. or if they looked at your other d18 thread. i am waiting for you and pearl to finish, so i can be corrected in my belief that a d18 is just a dream engine.

Assuming no more problems, mine should be running with low boost in a month.
let me know bro, i'll definately roll down the "hill" and see this happen. :TU:
 
#30 · (Edited)
A close look at the guts

Sorry, I didn't get a chance to post up another intallament last night. I spent 2 hours on the car and then got caught up in Game 5 of the Stanley Cup finals. But here goes...


Here's some close up shots of the assmbled rotating assembly (sounds redundant, huh?). Note the slight amount of block notching that's normally required for wider aftermarket rods. In addition, the main cap had to be notched to accomodate the wider swing of the crank. Both areas would still need to have been notched even with OEM rods because of the longer stroke.



Both the block and main cap notches can be seen in this shot.



The rods came with ARP rod bolts. And speaking of bolts, I briefly thought about using ARP main cap bolts or studs. I guess I figured on sparing no expense at building a strong engine and bolts are generally not that expensive. Anyone ever heard of man cap bolts failing? A friend of Mike Belben told me he used ARP main studs and it may have contributed to distorting the main bore. He says that he's heard of guys using H22 studs but you can't. So I ended up re-using the Y8 main cap bolts on Ken's advice. I know the re-use of main cap bolts has been recently discussed here in another thread. And BTW you can use the bolts from either the Y8 or D17. The D17 main cap fits the Y8 block also but the bore will be misaligned (unless you're lucky). It might be correctable with an alignment bore if it's close to spec.



Here's a shot of the machine that Ken presumably used for the notch work. I'm sure it does a much nicer job than me and my Dremel. I may have had trouble grinding into the iron sleeve. (For the n00bs: that's not a d-series block.)



This evening my 11 year-old daugher has a softball game so by the time we're done with that I'll be too bushed to work on the stroker. Instead I'll post more photos and rep all who have posted in the thread so far.
 
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