Ok I'll try to keep this short and simple. D16A6 block (212mm deck height) + D15B crankshaft (84.5mm stroke + D16 rod journal size) + aftermarket D16 rods (137mm length) + STOCK D15B7 pistons (30.7mm compression height) = 8.56:1 compression.

What, if any, aftermarket piston should I go with to maintain such a compression ratio? TunerToys sells 9.0:1 pistons, standard bore, but they don't give any kind of dome/dish CC volume, so I can't tell what the final outcome will be. Any help?

EDIT: Whoops, almost forgot. To maintain that compression ratio, I'd need a stock thickness (0.048in) head gasket. Does anyone make one around that thickness that won't break the bank (HK$)?

 

AHHHHHHHHHHHHHHHHHHHHHHHHHHHHH NIG!

 

How you gonna get that D15B crank to work in a in a D16 block?

The custom spacer bearings are still in the design stage, but why limit your self to 137mm rods?

Think about some 140.5mm B rods narrowered to fit D crank......

 

Hmm.. That might work also. Who makes 140.5mm B rods? All I could find was 137mm B18B and 138mm B18C rods.

And I was just assuming that since the D15B crank has the same rod journal sizes as D16 blocks, then it might have the same main journal sizes.. Guess I screwed up there. What's the difference in diameter?

I really kind of want to stick to the 84.5mm stroke, as to maintain some reliability with the larger rod/stroke ratio. So 140.5mm rods would be great, if I could find some pistons with a low enough compression height.

 

D16 = 55mm/45mm
D15B VTEC = 45mm/45mm
D15 normal = 45mm/42mm
D15 HF =45mm/40mm

 

Why bother?

 

Hype-B16 rods, Bone? I don't think he could get those for less than the cost of a set of Eagles.

RS is LIES.

 

See, but R/S ratio does have some truth. R/S does affect piston acceleration/speed. R/S does affect side loading. R/S does affect operating rpm range. These are all truths that cannot be denied. However, they can sometimes be remedied(read: helped, but not eliminated) with lighter components.

I'd genuinely like to know why you think that r/s ratio is all lies. Especially with these d16 heads that don't flow very well, I think slowing down the piston speed, per rpm, would net better cyl filling. Please, give me a clue.
-josh-

 

Honda makes that gasket.

How much do you plan on decking the block?

-josh-

 

I meant RS™, not rod/stroke itself. Still for 99.9% of cases you either boost what you've got or you're a ***** with too much money who's slower than 99.8% of the guys who just boosted what they had.

Here, I'll explain:

Yes, this is the only thing that is significant in a Honduh application. A "shittier" RS is always better for a boosted Honduh, period, end of story, HT Hypewagon bullshit and general faggotry can stay on HT. Pistons accelerate quicker, and this is a good thing. You can pack a really dense intake charge into a given engine size, where you'd be past knock limit, when the piston is decompressing the charge before pressures skyrocket and the charge explodes (detonation).

You can also suck on goat dick and be a complete TOO-loving NA *** and claim RS™ is important, and try to configure the Perfect™ RS™ engine when all the big name guys who make any power are going for the most stroke and bore they can get with no concern for the ****** RS™ niceties. Don't tell Widmer.

Irrelevant in tiny 75mm bore engines where all four pistons weigh as much as one piston in a engine where side loading is an actual concern. The alleged bore wear comes from forged pistons + low silicon aluminum expansion, and you can't get away from that unless you run something else (iron piston pls). But, then you are concerned with (OMG JDM Perfect™ RS™)²!!!222!!2, and not actual real world rod/stroke, you can't be convinced of that.

But not anywhere near as much as ingested airmass does. You know at the 500 whp level that stock B16 cams are still making power at 9500 rpms, power still climbing if the turbo is correctly sized? This can not be done with RS™, sorry. Yunick agrees.


On HT, anyway, when a JDMed out EK hatchcrap means you're right and people who build fast cars are wrong.

Air compresses, "small" ports don't mean so much. The D16 bore (and stroke, but only as much as displacement ever affects anything) is the limitation, not the cylinder head. Why else do a lot of D16 make the same power numbers as LS with the same turbo at the same pressure when the LS head flows "better," which anyone can tell you because of junk flowbench numbers and simple observation that the LS ports and valves are way bigger, duh.

You can be told 1.9 million times that gas flow is a wierd thing. You can observe it with a flowbench, and then see how flowbench numbers can be a general guide, but if you aren't on top of it power numbers and track times get worse despite superior JDM flow bench junk numbers coupled with the ultimate in RS™ Salesmanship And Marketing Technology. All this stuff is completely amazing!!!!1 and totally JDM!!1111!!!12 but what really drives it home is a good long study of CD aka Convergent-Divergent aka DeLaval nozzles. A CD nozzle chokes flow down to an opening that is stupid small ---> flow accelerates to sonic as it passes through this opening ---> but if the exit is a smooth enough transition and correctly expanded/contoured the flow (goes supersonic, temps drop drastically, pressure drops drastically) draws the flow on the other side of the nozzle out more efficiently than any size pipe (port, orifice, blah blah blah) that doesn't choke the flow. This is how Goddard turned insanely powerful 2% efficient liquid fuel rockets into insanely powerful 68% efficient goddamn ----------ers a hundred years ago. But, I digress. Head/bore situation can be described as an incredibly fucked up horribly designed CD nozzle arraingement, with a D16 configuration being the most worthless design ever. Except GM 4.3 V6, of course.

D16 is limited in power by it's BORE first, displacement second, head about fifth or sixth down the list. With forced induction, ALL of the tuning/reliability problems with a D16 are caused by the BORE. As you go from a stock to a built block, and the boost controller is JB Welded into the nig nog position, the BORE is what limits the flow into the cylinder and again compromises power. At no time are we concerned with rod/stroke, except the "shitty" rod/stroke that you want in a big power situation that comes with a stroked out motor, so it goes without mention.

Hoo-whee, coffee rules. I miss bourbon, though.