cams, sohc vtec vs non vtec

[redefine]

i was just curious, is there any big difference between the cams in the sohc vtec and sohc non-vtec engines?

i know the vtec cams have -exhaust-intake-vtec-intake-exhaust- for the valves in one cylinder, but besides the lobe for vtec, is there much difference?

in other words, does the non-vtec cam go -exhaust-intake-space-intake-exhaust-, or is it completely different?

(this is all looking at one cylinder out of the 4 btw)

[trism]

i believe that yes,there is a space

[Limbo]

not much, the vtec sohc are abit more fuel efficient.
Performance wise bugger all

[redefine]

hmmm, i need to take the rocker cover off my ek methinks (its a non vtec sohc)
is there anything i need to keep in mind when doing it?

[beeza]

Yes yes!
I just changed the valve cover gasket and the spark plug hole gaskets (4 of them).$28 and $68 respectively.$68 is expensive but aye it's honda!
If you haven't changed the Valve cover gasket,I would do that but first check if the spark plug gaskets have splits in them and need replacing.If oil is getting into the spark plug holes and onto the leads and plug then there's a split in them.
More than likely they will be fine.It's only if you have taken the cover off before and wasn't careful with them when putting them back on.
Clean the surfaces well.Fit the new gasket.Use a gasket sealant like 'Ultra grey'.You only need to put it in the gasket groove at the camgear end.
Take care with the spark plug gaskets and make sure the valve cover bolts go in strait.Don't do what I did and strip some of the thread on the head.On 2 of them! Doh!...I went strait to Hondarec and got 2 sligtly longer bolts and it worked!
Torque the valve cover down in this order.First finger tight then tight/firm.

------------------------- *2 *3
------------------------ *4 *1 *5

[redefine]

thanks!

do the gaskets need replacing often? i dont know if mine have been changed in the 112000k's its done

[beeza]

The spark plug hole gaskets don't,the valve cover gasket only needs replacing if you take the head off a couple of times but I've taken mine off a few times and all is good.
Make sure you do it when the engine is dead cold too.
Your welcome :)

[nd55]

> i know the vtec cams have -exhaust-intake-vtec-intake-exhaust- for the valves in one cylinder,

The difference between the D16 vtec and non-vtec is much more pronounced in the US models.

Local versions (D16Y4,D16Y5 and D16Y8) all got good intake/exhaust manifolds so there's only about 8Kw difference.

The biggest difference is in the gearboxes. The Vtec D16's generally have slightly better gear ratios.

The D16Y8 is a traditional small cam/big cam style vtec mechanism. This engine is fairly rare locally cause it only came in US made coupes.

The D16Y5 is a i-vtec. This means there's only one cam profile.
ie: exhaust - intake - nothing - exhaust

the valve with the missing intake cam lobe does nothing up until about 3000rpm, when it locks to the other intake cam lobe and they move together.

Actually, this is a fairly oversimplified. The 'nothing' lobe is a very thin (width) very low lift lobe which exists purely to prevent fuel puddling behind that valve. Apart from opening the valve a crack it does nothing.

Nick.

PS> Get a Helms manual if you're going to be turning some serious spanner work. It's worth it's weight in gold.

[redefine]

thanks heaps! most of what i do to my ek, i wanna be diy, rather then bolt on (so i learn more about it), so i'm prob gonna be doing more and more spanner work as my budget grows (eventually) :)

and i have the d16y4, so i'm guessing it wont be much improvement.

a little OT, but what is the major design difference between the d series and the b series?

[Raztaz]

thanks heaps! most of what i do to my ek, i wanna be diy, rather then bolt on (so i learn more about it), so i'm prob gonna be doing more and more spanner work as my budget grows (eventually) :)

and i have the d16y4, so i'm guessing it wont be much improvement.

a little OT, but what is the major design difference between the d series and the b series?

well the B's are DOHC's, thers a big improvement on our single cam D series lol (we dont get DOHC D16A1 n 2 in Aus)

[redefine]

ahhk, other then that is there any major difference?

i'm guessing they'd generally be more robust/higher temp etc.

[trism]

there is ALOT of diffs between the d and b

they were designed for totally different purposes

the D was the engine for family cars, base models etc

the B was designed as a performance engine

go and do some research

[redefine]

i tried, but all i got were swap guides and the 'this is a better engine' thing, not what is actually different about the engine.

i know what they were designed FOR, i'm looking for how they were designed for that

[nd55]

> the B was designed as a performance engine

The single/dual cam difference is less important than the geometry of the
engines.

D16's came in DOHC versions, but aren't the same fire breathing animal as the B16's.

Conversly, 8000rpm is within the capability of a SOHC design, but the offset spark plug necessary isn't the best design, nor is the marketing. :cool:

The B16 is actually a detuned motorcycle engine. :cool::D

The D16 had better output numbers at cruising rpms. The B16 is much superior at high revs and is where it shines.

IMHO, the biggest differences are.

D16 75mm bore x 90mm stroke. 31mm intake valves.

B16 90mm bore x 75mm stroke. 33mm intake valves.

[redefine]

thanks nd55, thats what i was wanting to know :)

[trism]

dude you could have found all that information by using google

ozhonda isnt the only honda website in teh world

[twing]

The D16Y5 is a i-vtec. This means there's only one cam profile.
ie: exhaust - intake - nothing - exhaust

the valve with the missing intake cam lobe does nothing up until about 3000rpm, when it locks to the other intake cam lobe and they move together.


i-vtec is vtec + vtc (valve timing control).
All D series don't have VTC. D16Y5 is vtec-e (economic) = 12 Valve Low RPM, 16 Valve High RPM.

[SeverAMV]

Conversly, 8000rpm is within the capability of a SOHC design, but the offset spark plug necessary isn't the best design, nor is the marketing. :cool:

with arp rod bolts on stock rods and lumpy cams, people have hit and made power at 9300rpm on a d15b4 before.

and NA power isnt too bad when tuning a D either. actually costs cheaper to get the same power from a D than it does for a B if you know where to look.

[nd55]

> i-vtec is vtec + vtc (valve timing control).


touche.


> made power at 9300rpm on a d15b4 before

Bisi aside, a parking lot of d15's still don't qualify as power.

:cool:

Nick.

[redefine]

dude you could have found all that information by using google

ozhonda isnt the only honda website in teh world

i realise that, but i didnt want to sift through 100 pages of fanboy drooling and flamewars to get to what i wanted to know (and i did sift through quite a few when i searched) so i came here and just asked. i figured there wouldnt be a problem with that, as i couldnt see any other threads on it (i searched again).

[trism]

:thumbsup: