Building a D15?
06-29-2004, 08:18 PM
#1
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Building a D15?
so i'm getting a JDM D15B for my EH here soon, and i will have my old D15B8 laying around....and i was wondering...has anyone built up a D15? I mean, if you could rock like 15-20 psi on a little D15 that would kick....i'm sure it'd take alot of work, but you could be proud of what ur little engine could do....i mean everyone hooks up their D16's or goes B-series....why not be different?
and to the person who says, there's a reason they hook up their D16's or goes B-series....like i said...to be different....i'm not looking to smash all the cars that i would ever come up against, just to be powerful, and different...
so what would u think of a built D15? any comments?
and to the person who says, there's a reason they hook up their D16's or goes B-series....like i said...to be different....i'm not looking to smash all the cars that i would ever come up against, just to be powerful, and different...
so what would u think of a built D15? any comments?
06-29-2004, 10:56 PM
#3
it's my D in a B
IMO, there is no tangible difference between the d15b and d16z6 in terms of performance potential, or just about anything else for that matter. You'd be "different" in tems of engine-code (for what thats worth), but not for any other reason. The fact that nobody builds up their d15b is more atributable to the relative rarity of the motor itself than the performance potential of that motor, or any other.
That said, since you're getting the motor anyway, do what you want with it. If you want a built and heavily boosted d15b, go for it. More power to you. I would like to see what you could do with it.
That said, since you're getting the motor anyway, do what you want with it. If you want a built and heavily boosted d15b, go for it. More power to you. I would like to see what you could do with it.
06-30-2004, 07:25 AM
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just for clarity....i'm talking about building up my D15B8, not the JDM D15B, although i will make a few slight mods to the JDM D15B. that is why i was talking about being "different" because i have yet to see a built up D15B8.
alpha, yes, the D15B8 has toothpick rods, but that's why i would strip to block and build up from that.
alpha, yes, the D15B8 has toothpick rods, but that's why i would strip to block and build up from that.
06-30-2004, 08:46 AM
#6
the d15b8 has 8 valves, you should do a d15b7 head swap and you have another 25-30 hp right there. talk to jafro about that because he did that same thing. is it possible to stroke the d15 with d17 internals??? has anyone ever done this?
06-30-2004, 09:20 AM
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Personally, I wouldn't try it. This kind of thread has popped up from time to time, and I always feel obligated to say something... I'd junk a 8-valve 1.5 liter. That's what I did with mine.
While it "could" be possible to build a D15B sleeper, some things you'll need to make it hold boost reliably will all have to be custom-fab. The valves suck, the manifolds are tiny, the rods are light and weak, the pistons are crap, the fasteners are junk, the crank has thin rod journals, and the wrist pins are dinky. The D-series block's floating-sleeve design is a recipe for disaster with boost. You can't do it without sleeves. Who makes a sleeve for a D15? You can buy at least 4 D15 short blocks for what the sleeve costs.
...so you need to replace the head, the manifolds, pistons, rods, crank, sleeve the block, use all new ARP chromoloy fasteners, dual valve springs and a different cam... ...then you might be able to hold boost... and maybe make about as much power as a B18 LS motor. The grinding, boring, honing, pressing, turning, decking, o-ringing, porting, sleeving... labor is probably going to be around $2500-$3000 because of all the custom work that will be required, and expect to pay around $2500-$3000 for parts depending on how much of it needs to be custom fabbed (crank, pistons, and sleeve). Headwork ain't cheap either. I'd just replace that head outright.
I'm not saying I think building a D15B wouldn't be cool. Hell, I did it with a D15B7, but at least mine was a 16-valve motor. The D15B8 is an 8 valve motor, and it's pathetic. You'd better have money to burn, because you'll probably end up with less motor than a stock B18 for more money spent.
If you want to go fast, there are other cheaper alternatives with just as good of a power/weight ratio. Like a Hyundai Excel hatchback with a $400 2.0L 4g63 NA swap. It's a bolt-in 140hp/140tq affair in stock NA fashion. That engine can hold 400hp on STOCK rods/pistons/crank if you boost it, and the "junkyard" turbo setup can be made from 100% factory parts with no custom fabbed anything. Maybe it's just the DSMer in me telling you this.
The machinist in me is saying... unless you want a museum piece that everyone questions the logic of, I'd scrap that idea. Yeah it would be cool, different, but why all that trouble and cost? If you installed that engine and tranny on a bar stool, then it would be really sweet, but put something better in your civic than a D15B8. There's no question your old motor was a great motor with 277k miles on it, but you got lucky. My D15B8 only went 104k before it lost compression. If you do anything, just put a DX head on that sucker, and call it a day. It's worth 35hp at the crank, and an extra 2000 RPMs to red-line with a DX ECU. Mine makes as much tq as hp which is odd for a Honda.
Edit: There's a full write-up of D15 guts in my sig. The rods and pistons of a CX/DX are the same. The pistons are even the same... the 8v pistons still have 4 fly-cuts on the top for a 16 valve head... go figure. The head casting is the same between the two. The valves are identical. The 16 valve just has another 2 valve ports bored through the exact same casting. The intake manifolds, exhaust manifolds, throttle bodies, o2 sensors, ECU's, injectors are very different, so if you can just get the top-half of a D15B7 + the ECU, there's your swap. Don't go higher than 9.5:1 on your pistons, and for the love of God, don't boost or spray it. Check my dyno sheet, my motor's 9:1 with stock internals and a 1-angle valve job. Those figures are hp/tq at the wheels, and that's about what a stock 95 si hatch does. Not bad. Use a different gearbox if you autocross. I kept the CX gearbox, and I only have to shift once to reach 80 mph. 3000 RPM's in 5th gear is 92 mph. It's not a transmission for racing, but I still get over 40mpg on the highway.
While it "could" be possible to build a D15B sleeper, some things you'll need to make it hold boost reliably will all have to be custom-fab. The valves suck, the manifolds are tiny, the rods are light and weak, the pistons are crap, the fasteners are junk, the crank has thin rod journals, and the wrist pins are dinky. The D-series block's floating-sleeve design is a recipe for disaster with boost. You can't do it without sleeves. Who makes a sleeve for a D15? You can buy at least 4 D15 short blocks for what the sleeve costs.
...so you need to replace the head, the manifolds, pistons, rods, crank, sleeve the block, use all new ARP chromoloy fasteners, dual valve springs and a different cam... ...then you might be able to hold boost... and maybe make about as much power as a B18 LS motor. The grinding, boring, honing, pressing, turning, decking, o-ringing, porting, sleeving... labor is probably going to be around $2500-$3000 because of all the custom work that will be required, and expect to pay around $2500-$3000 for parts depending on how much of it needs to be custom fabbed (crank, pistons, and sleeve). Headwork ain't cheap either. I'd just replace that head outright.
I'm not saying I think building a D15B wouldn't be cool. Hell, I did it with a D15B7, but at least mine was a 16-valve motor. The D15B8 is an 8 valve motor, and it's pathetic. You'd better have money to burn, because you'll probably end up with less motor than a stock B18 for more money spent.
If you want to go fast, there are other cheaper alternatives with just as good of a power/weight ratio. Like a Hyundai Excel hatchback with a $400 2.0L 4g63 NA swap. It's a bolt-in 140hp/140tq affair in stock NA fashion. That engine can hold 400hp on STOCK rods/pistons/crank if you boost it, and the "junkyard" turbo setup can be made from 100% factory parts with no custom fabbed anything. Maybe it's just the DSMer in me telling you this.
The machinist in me is saying... unless you want a museum piece that everyone questions the logic of, I'd scrap that idea. Yeah it would be cool, different, but why all that trouble and cost? If you installed that engine and tranny on a bar stool, then it would be really sweet, but put something better in your civic than a D15B8. There's no question your old motor was a great motor with 277k miles on it, but you got lucky. My D15B8 only went 104k before it lost compression. If you do anything, just put a DX head on that sucker, and call it a day. It's worth 35hp at the crank, and an extra 2000 RPMs to red-line with a DX ECU. Mine makes as much tq as hp which is odd for a Honda.
Edit: There's a full write-up of D15 guts in my sig. The rods and pistons of a CX/DX are the same. The pistons are even the same... the 8v pistons still have 4 fly-cuts on the top for a 16 valve head... go figure. The head casting is the same between the two. The valves are identical. The 16 valve just has another 2 valve ports bored through the exact same casting. The intake manifolds, exhaust manifolds, throttle bodies, o2 sensors, ECU's, injectors are very different, so if you can just get the top-half of a D15B7 + the ECU, there's your swap. Don't go higher than 9.5:1 on your pistons, and for the love of God, don't boost or spray it. Check my dyno sheet, my motor's 9:1 with stock internals and a 1-angle valve job. Those figures are hp/tq at the wheels, and that's about what a stock 95 si hatch does. Not bad. Use a different gearbox if you autocross. I kept the CX gearbox, and I only have to shift once to reach 80 mph. 3000 RPM's in 5th gear is 92 mph. It's not a transmission for racing, but I still get over 40mpg on the highway.
06-30-2004, 09:55 AM
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Originally Posted by s1ngle
4g63 swaps are $400? Do Hyundai's run Mitusbishi motors? gee, i learn something new every day...
I just sold a '91 4g15 Mirage hatchback that runs (blown tranny, tho) with 4 brand new tires, to the guy that gave me both of my D15B7's for $60. It's on the short-bus page. Has every bit of interior room that a civic does. Even more in the back seat. If I bought one of these before I bought my civic, I wouldn't be typing here right now. There's a video of a 4g63 swapped Hyundai on my oddities page. This link may not work, but it's here: http://homepage.mac.com/jafro/.cv/ja...wmv-binhex.hqx
06-30-2004, 05:03 PM
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Back on topic:
Not being able to affordably sleeve a Honda 1.5L block is what stopped me from doing what you were asking about. That... and Eagle makes 1.5L rods, but they don't make a crank for a 1.5L. Who does? I don't know the limits of a 1.5L crank, and with the rest of the cost of machining, I don't know if it's worth it with the stock crank.
If you really wanted to boost it, at least put a head that flows better on there, like the B7 head. You can still put the sleeper 8-valve valve cover back on it because the 1.5L valve covers are unique to the 1.5L engines. The valve cover from a DX or Del Sol has "16 Valve" cast into it. The B8's are the plain crusty black ones.
You can use the B8's exhaust manifold to hack a turbo flange onto for whatever turbo you want to use, www.machv.com sells blank flanges for various BOV's Turbo exhaust housings, Exhaust flanges, etc... Most machine shops can either weld on the flange, or make a bolt-on adapter plate without too much trouble. A lot of people go this route if they don't want to buy a manifold or a turbo kit.
Use a set of 450cc DSM injectors. Used. So many turbo DSMs came with these. They're always being sold, most likely by someone in your neighborhood. Re-plumb your fuel system, get a Walbro in-tank fuel pump, get an aftermarket filter and regulator, set FP at 37 or 38 PSI. Tune your A/F ratio with an Apex'i S-AFC.
You'll need to replace your exhaust. You can get your BOV mounted on the intercooler end tank and hide it inside the fender so your upper intercooler pipe looks like a AEM cold air intake. Use a 2g DSM side-mount IC, and cut the plastic fog light hole out of your bumper. Nobody will know you're boosted if you can find a quiet enough BOV, and if you can make a heat shield that hides the turbo.
There. That's what I've always wanted to do to mine. 'Sorry 'bout the thread-jack. 'hope some of the Honda stuff mentioned was helpful.
Not being able to affordably sleeve a Honda 1.5L block is what stopped me from doing what you were asking about. That... and Eagle makes 1.5L rods, but they don't make a crank for a 1.5L. Who does? I don't know the limits of a 1.5L crank, and with the rest of the cost of machining, I don't know if it's worth it with the stock crank.
If you really wanted to boost it, at least put a head that flows better on there, like the B7 head. You can still put the sleeper 8-valve valve cover back on it because the 1.5L valve covers are unique to the 1.5L engines. The valve cover from a DX or Del Sol has "16 Valve" cast into it. The B8's are the plain crusty black ones.
You can use the B8's exhaust manifold to hack a turbo flange onto for whatever turbo you want to use, www.machv.com sells blank flanges for various BOV's Turbo exhaust housings, Exhaust flanges, etc... Most machine shops can either weld on the flange, or make a bolt-on adapter plate without too much trouble. A lot of people go this route if they don't want to buy a manifold or a turbo kit.
Use a set of 450cc DSM injectors. Used. So many turbo DSMs came with these. They're always being sold, most likely by someone in your neighborhood. Re-plumb your fuel system, get a Walbro in-tank fuel pump, get an aftermarket filter and regulator, set FP at 37 or 38 PSI. Tune your A/F ratio with an Apex'i S-AFC.
You'll need to replace your exhaust. You can get your BOV mounted on the intercooler end tank and hide it inside the fender so your upper intercooler pipe looks like a AEM cold air intake. Use a 2g DSM side-mount IC, and cut the plastic fog light hole out of your bumper. Nobody will know you're boosted if you can find a quiet enough BOV, and if you can make a heat shield that hides the turbo.
There. That's what I've always wanted to do to mine. 'Sorry 'bout the thread-jack. 'hope some of the Honda stuff mentioned was helpful.