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· Nor Cal D-series rider
2017 FK8 Type-R / 1993 DX hatch
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1,281 Posts
Discussion Starter · #1 · (Edited)
Hey guys! Just checking if anyone here has experience with this combo, as I just bought a D16Y8 that had a mystery bottom end inside it. I am looking to run the following for a fun street NA build that can surpass 140whp, keep in mind I live at 6,000 feet elevation which lowers effective compression.

D16Y8 block
75 mm PG6B pistons (86-87 Integra D16A1)
H-beam rods
D16Z6 head, fully ported
SpeedFactory Street Savage camshaft (+11% intake and exhaust valve lift)
Rocket Motorsports springs and retainers
Adjustable cam gear
Y8 ARP head studs
Skunk 2 Pro intake manifold, port-matched
70mm throttle body
Z6 240cc injectors, flow matched
Longtube race header
Full 3" exhaust
Hondata S300 with flex fuel

This yields a 11.67 compression ratio on 3-layer head gasket, 10.47 effective CR with elevation. We have E-85 gas stations here. My main concern is PTV clearance (Piston to Valve). I will clay it up, but know things loosen up around 8,000 RPM.

Any input appreciated,
Thanks.
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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1,620 Posts
No need for long tube header, 70mm tb, or 3" exhaust, the combo of those 3 things is going to kill your torque and make it 0 fun to drive on the street. Get a z6 mani, a tri-y header, 2" exhaust, and a 60mm tb off a b16, and leave the rev limiter at 7500 rpms. You will make your power goal, possibly exceed it, but retain more bottom end drive ability, plus your engine will last longer. With proper tuning it will even pass ca smog, so long as your smog shop only cares about a functioning evap, cat and a good gas test.
 

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10,083 Posts
Money can be saved here.

You need a tuning solution. So make the best of it. Use modern fuel injectors.

Keep the stock d16z6 throttle, or at most, a 60/62mm

Port the throttle throat of the z6 intake manifold. Create an anti-reversion spot. Be careful to note the IACV feed hole.
Clean the runners up of casting flaws. dig into the roof a little, and clean up the injector bosses to create a ncie flow increase.


Find a 99-00 d16y8 exhaust manifold, cut and weld a new 2.5" collector on it. V-band it. Now install a 2.5 to 4" megaphone on it, and drop it down to a 2.25" exhaust. Plenty of flow.



With ONLY the compression increase, and otehrwise stock head setup (except valvesprings, get those), and tuning with modern fuel injectors, you will have a HUGE increase in torque, throttle response, and power, due to much better fuel mixture/atomization.


If the only thing you do to a stock d16z6 is tuning with modern fuel injectors, you can create more than 125whp quite easily on 91 or 93 octane. The compression will help with the small exhaust ports, and ONLY a mild camshaft upgrade is needed.


You only really need a camshaft upgrade if you are planning on revving beyond 8500 rpms. The stock cam makes great power as it is.


These engines are old, high mileage, and getting forgotten about. A refreshed topend with valve guides, proepr valve lash, and modern fuel injectors makes such a huge difference




EDIT


E85 is completely unnecessary on this engine. The extra ignition timing from E85 does not always outway the lower energy of the e85 fuel. Also, most e85 stations can have fuel as low as e55 and still pass the e85 naming requirements. SO at that point, good quality 91 will work fine.
 

· Nor Cal D-series rider
2017 FK8 Type-R / 1993 DX hatch
Joined
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1,281 Posts
Discussion Starter · #5 ·
Thanks for the replies guys. The previous owner says he built the Y8 for boost, but I feel his shop bought the wrong pistons and he probably wanted Vitaras, which may be why I ended up with such a good deal on this 11.67 compression engine.

I just haven't found much confirmation on PTV with PG6B pistons and Z6 head, I know P29s clear. I do have a Tri-Y header, Z6 intake mani/TB/injectors/spare P28 to unlock for tuning for a more streetable build. I can gain a tiny bit more clearance by retaining the stock camshaft and a thicker head gasket, which of course lowers compression. I don't want to fly cut the valves but will if it won't clear, the Z6 head hasn't been delivered to me yet to check clearances.
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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1,620 Posts
So long as your timing belt never jumps a tooth you will be fine on clearance, even with the aftermarket cam.
Should be noted im running a stock z6 cam and only 9.98:1 compression on a decked block with p2p pistons, ported head, port matched z6 mani, lean burn tune, and putting down right about what you are looking for. A dynamic balance on the bottom end helps broaden the power band, and keeps the bores from ovaling, motor currently has in excess of 180k miles on it, gets beaten on daily.
 

· Nor Cal D-series rider
2017 FK8 Type-R / 1993 DX hatch
Joined
·
1,281 Posts
Discussion Starter · #7 ·
These engines are old, high mileage, and getting forgotten about. A refreshed topend with valve guides, proepr valve lash, and modern fuel injectors makes suchompletely unnecessary on this engine. The extra ignition timing from E85 does not always outway the lower energy of the e85 fuel. Also, most e85 stations can have fuel as low as e55 and still pass the e85 naming requirements. SO at that point, good quality 91 will work fine.
I mostly agree with your entire post. In regards to E-85, thankfully the newest Hondata S300 can handle flex fuel sensors to keep a small, safe target octane buffer with E-85 + mostly 91 octane blends should I get any pinging on 91, especially if I drive to lower elevations. Hondata's Flash Pro flex fuel works flawlessly on my Type R.

So long as your timing belt never jumps a tooth you will be fine on clearance, even with the aftermarket cam.
Should be noted im running a stock z6 cam and only 9.98:1 compression on a decked block with p2p pistons, ported head, port matched z6 mani, lean burn tune, and putting down right about what you are looking for. A dynamic balance on the bottom end helps broaden the power band, and keeps the bores from ovaling, motor currently has in excess of 180k miles on it, gets beaten on daily.
Thank you, sweet build and longevity BTW! I don't think the shop balanced my rotating assembly, but know the bores were honed and big ends of rods were machined along with crank journals. Fingers crossed that there's sufficient clay left when I turn the crank, then I can calculate how feasible the SpeedFactory bumpstick is.
 

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The PG6 pistons have a very meaty top, so you do have plenty of room to get pretty tight with valve reliefs, if it gets to that point.


Nothing claying the motor wont tell.

You do not need to get a thicker headgasket. Not until you worry about clearancing the valvetrain oil buckets, do you really need to worry about the pistons to much extent. Just a bit of de-shrouding the valve pockets to ensure if the timing belt stretches at high rpm, it doesnt kiss something it had no permission to do so.


I really need to re-iterate and re-enforce, modern fuel injectors make all the worlds of difference. Better tunability, super crisp partial throttle response, and just an overall feeling of a larger engine.



This is one of the reasons a factory D17 from the 01-05 civics feels so goddamn smooth when they are running perfect. ANd that is a small conical pattern 4-hole injector style.


ID600's are a good example of a great pattern. I have a set that were for other projects at the time, but I think I am doing a very basic tuned setup F23 for my Insight.
 
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