Spade

HAHAHAHAHA......well I don't know the duration aspects of the cams I do know this though......The HX cam lobes are bigger than the EX cam lobes!!!!

D16Y5
Intake
Primary......38.4mm
Secondary..32mm
Exhaust.......38.8mm

D16Y8
Intake
Primary.....36.8mm
Mid............38.3mm
Secondary..37mm
Exhaust........38mm

And for those of you who don't know the HX above 3000 connects both valves together and they both use the 38.4 lobe.

Overall, I believe that the D16Y5 is a more powerful engine and just needs the same sized manifold of the D16Y8 with the same tranny gearing. And I plan to do both and leave the engine stock and Dyno. I own an EX and an HX I will dyno both some time next summer and prove my theory.

Edit: I forgot one more thing.....the HX has roller rockers too!!!


[Modified by Spade, 8:10 AM 12/14/2001]


Modified by Spade at 1:35 PM 11/17/2003

DragII

???

Spade

Interesting no? I thought so too when I was looking it all over last night.........I just am wondering if the durations are close or not.....just because the cam lift wouldn't mean **** if the durations are way off. But in the meantime I have a better cam and better gas milage

DragII

but the HX vtec operation is WAY differant than any other vtec motor. it is not at all made for making power.

Spade

your right it is different but not by much......above 3000 rpm it uses both valves on the larger cam lobe. Who the hell drives below 3000 RPM?

EDit: and good god look at the exhaust cam .8mm more!!!


[Modified by Spade, 10:13 AM 12/14/2001]

DragII

Interesting....*goes to read up on the HX*

Spade

Please let me know if you find out about the durations and degrees on the cams......the whole reason I looked at the cams to begin with is I am trying to complete a Specs sheet for D series and then I will do one on B series.

Plus, I have run at EX's more than once and either beat them or come VERY close.

CivicFerio

Remember my SOHC VTEC cam lobe and follower wear? I might change to an HX valvetrain if excessive wear still persist.. You have to note that roller rocker operate in a different geometry thus the stock cam with a higher lift might not mean anything.

Charleston

DragII

Exactly what I was thinking.

Spade

True another interesting thing to look at.........I still feel that the HX has more potential if it was allowed to breath like the EX is.

CivicFerio

I just got my SOHC EX head ported and I got to tune it on a BOSH dyno... I we were able to get 132whp which is not too bad.. Considering I that I only have DC 4-1 header and head works.. So at least we have a base line now if I were to convert to an HX valvetrain

Charleston

CivicV10@18000rpm

I'm wondering why the d16y8 (vtec) has 3 different lobe heights and the d16y5 (vtec-e) has only 2 different heights? I was reading a Haynes repair manual and it said for the d16y8(vtec) "The camshaft used in this system has identical primary and secondary lobes and has a additional third lobe...." Sometimes I wonder about the accuracy of these repair manuals.

Spade

The EX uses the pri and sec until vtec then both valves use the mid.
the HX uses the pri and mid until vtec then both valves use the pri.

CivicFerio

The D16Y8 head during low lift, the one of the intake valve is pushed further compared to the other to promote swirl in the combustion chamber hence more torque and less emission. On the other hand the HX only opens one intake valve for maximum turbulance in the combustion chamber and then both valves at higher RPM...

B18C5-EH2

That's pretty ******* cool - it's cool to see someone who's still doing **** with the D-series motors.

If the HX didn't have that shitbox tranny it would definately run a lot better. a Pal of mine had a VX that was ****-slow until he swapped in a 1994 Si tranny - made it run a LOT better.

Spade

Wrong! at least on the HX valves....the HX valves both open just the difference is more drastic than that of the EX....I.E. 38.4mm primary and 32mm secondary!

Spade

I am going to get the tranny and EX intake, fuel rail, trottle body, injectors basically anything attached to the EX intake manifold...in January and see what the difference is.

CivicV10@18000rpm

But in the manual it says for the D16Y8(vtec) primary and secondary are different while in the same manual but later in the same chapt for the same engine D16Y8, it says primary and secondary are identical. The HX D16Y5 (vtec-e) doesnt have a mid lobe according to your lobe heights and the manuals lobe hieghts....correct?

Spade

Correct and I have seen the cams of both.....the HX doesn't have a mid lobe and the vtec just joins the two valves together to use the primary lobe.

What manual are you reading? I am looking at the Haynes

CivicV10@18000rpm

I'm reading the not so great haynes manual too.

Spade

I kinda ignore anything that isn't a measurement in there manual....I have actually watched the the heads of both the EX and the HX without the valve cover on. Pretty cool but I wouldn't do it in a dusty area.

Mista Bone

But the VTEC-E heads use TINY valves. All is lost.

BlackDeuceCoupe

Oh, bullsh!t !!! Why don't you chimps go look up stuff before you start shooting your collective mouth off? It makes you look more retarded than you are!

The EX and HX use identical valves. The intakes are part #18245 and cost $18.25 each. The exhausts are part # 18246 and cost $29.52 each. Once again, they are exactly the same. Go look it up on Majestic Honda's web site if you don't believe me...

BlackDeuceCoupe

You've been doing a great job of defending the HX, Spade, but you've over-simplified it a bit here. The pri and sec valves will actually lock anywhere from 2500-3200 RPM, depending on conditions, not simply "above 3000 RPM."

For you others; look, it's V simple. The HX has a hotter cam than an EX - period.

The pri intake valve ALWAYS runs off one lobe, and it's hotter than the EX's biggest lobe, as he said.

The sec intake valve runs off a V small lob in 'E' mode, but it DOES open slightly, despite what some of you monkeys may think [and say]. This is so 'gas puddling' around the sec intake valve pocket doesn't occur. The sec intake valve locks itself to the pri valve when power is needed. That's the reason for the roller rockers in the HX; so Honda doesn't have to use stiffer valve springs to accomplish all this. It came from S2000 technology, but that's a different story...

Simply put, there is NO way an EX is going to beat an HX coming off the line hard. Whatever the HX gives up in horsepower, it makes up for in spades [no pun intended], in the weight department. Stock vs. stock, an HX will beat an EX every time; top-end, low-end or in the middle.

As far as the tranny goes, sure, the HX's final drive is higher, but the gear ratios themselves are closer together. That means an EX [effectively] has a wide-ratio gearbox compared to the HX's close-ratio gearbox. What does this mean in REAL life??? The HX will gain almost a half car-length over an EX on every shift 'cause it doesn't run out of revs as fast.

Anyway, Spade, keep tellin' it like it is, and I'll set you straight when needed...


[Modified by BlackDeuceCoupe, 7:26 PM 12/15/2001]

thefordmccord

HX!!!!!