CwestGurl

Wow scary I actually understood what you wrote. I learned something new today.

Miracle

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CwestGurl &raquo;</TD></TR><TR><TD CLASS="quote">Wow scary I actually understood what you wrote. I learned something new today.</TD></TR></TABLE>
See, thats what I am going for right there.

I appreciate that.

Miracle

Here are a couple videos on the sound of VTEC engagement...

1998 CW ITR:
http://videos.streetfire.net/s...6.htm


N/A LS/VTEC B18:
http://www.youtube.com/watch?v=L1wtfSHEO-U

S2000:
http://videos.streetfire.net/s...8.htm



Modified by .Red.EM2 at 4:45 AM 9/20/2006

iwantspeed

when i bought my car it had a vtec light installed... i dont know where the wires connect to but it works... most of the time it comes on at around 3300 rpms.

Miracle

Here are a couple more illustrations of a VTEC valvetrain...

The rocker assembly, the VTEC rocker colored in yellow, and the low RPM rockers in red and blue. Note the locking pin assembly in 2 pieces:



An original Honda illustration, showing how the pin inside the rockers slides over with oil pressure, locking the 3 rockers together...

Metalluthier

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Red_EM2 &raquo;</TD></TR><TR><TD CLASS="quote"><U>UPDATED 8-2-06</U>

In a SOHC VTEC motor, the camshaft sits centered in the head, so both of the intake and exhaust valves are engaged on the same camshaft.
There are 3 camshaft lobes on a VTEC camshaft. The three cam lobes in the middle are the intake cam lobes. <U>The two low RPM (the shorter of the 2 profiles) lobes actuate two valve rockers, which in turn pushes the intake valves open.</U>

</TD></TR></TABLE>


Actually, the way the spark plug is located on SOHC VTEC engines, it is impossible for VTEC to work for the exhaust valves


DJ AnalogDuck (various artists - mix) - Eastern Duck Heads West (2001) - 05 - Eastern Duck Heads West05.mp3 [192Kbps] (05:54)

Miracle

I think you misuderstood.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Red_EM2 &raquo;</TD></TR><TR><TD CLASS="quote"> In a SOHC VTEC motor, the camshaft sits centered in the head, so both of the intake and exhaust valves are engaged on the same camshaft. </TD></TR></TABLE>

I didn't say that VTEC operated both the intake and exhaust valves, but rater that the cam sat centered in the head, and that IT operated both intake and exhaust valves under normal operation.

myst

wow

Phil McConkey

The title made me laugh for some reason, lol.

mholt

Anyone know alot about the K20A3?? I have an 02 Civic SIR, up in Canada, and it seems when it gets a little colder then normal outside the engine makes a high pitched whining noise. Is this normal for these motors? I bought the car when it had 28000 km on it and it started making this weird noise at about 32000 km. I've asked my local dealer what it is and each time they say they will try to figure it out and then they give it back to me telling me that it is because it has a timing chain instead of a belt, and when i ask why it wasnt doing it befor they tell me because it wasnt worked in yet....

Any advice for me anybody? And one more thing. Should there be a kik in the pants when the vtec kiks in?...the car has good power but i can't always feel that extra kik when you hit a certain rpm.

any advice or help is appreciated.

thanks

Curiouz_G

wrong forum

lorence

hey im new here and i noticed my v-tec doen't kick in at all when it should because i have an 01 ex. also my car's been laggin meaning running kinda slow. Anyone know wat could be wrong wit it?

Miracle

Probably needs a decent tune up, and you really will not feel the VTEC in the D17A2 "kick" It is just that harsh of a transition. You will know it, but it won't be like the old B series crossovers.

toyomatt84

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lorence &raquo;</TD></TR><TR><TD CLASS="quote">hey im new here and i noticed my v-tec doen't kick in at all when it should because i have an 01 ex. also my car's been laggin meaning running kinda slow. Anyone know wat could be wrong wit it? </TD></TR></TABLE>

It does kick in, but it's very difficult to "feel" the changeover. A good test would be to accelerate normally from 1,000 - 2,200 rpm's, then go to Wide Open Throttle through 3,500 rpm's. You'll notice a slight change in pitch, when the rpm's reach about 2,700 (VTEC kick-in point).

Boilermaker1

how it works in this piece.... with the real parts
This is an A2 cam


2 outers are the exhaust lobes
there 1 intake lobe and a circular lobe

This is the intake rocker assy


the one on the left has a roller on it and the other one has nothing.
At low RPM, it runs 1 intake valve. At high RPMs, a pin locks the rockers together and both open.

TN90accord

OK, SO THE D17A2 IS VTEC-E??? On wikipedia it says we have SOHC VTEC, and there was just a thread that brought this up. Everyone in that thread was saying we had SOHC VTEC and not VTEC-E. I think its VTEC-E or else the engagement point wouldn't be so low. Also if these pics are from an A2 this kind of proves its VTEC-E.

toyomatt84

iTrader: (1)

None of the K-series engines are VTEC-E. The only engine that's VTEC-E in the 7thgen lineup, is the D17A6 which came with the Civic HX.

Boilermaker1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by toyomatt84 &raquo;</TD></TR><TR><TD CLASS="quote">None of the K-series engines are VTEC-E. The only engine that's VTEC-E in the 7thgen lineup, is the D17A6 which came with the Civic HX.</TD></TR></TABLE>

Depends on how you want to define that. The K20A3 is intake only and operates in a very similar manner. Its got a big lobe and a little lobe on the intake side, when VTEC engages, it puts both valves on the big lift lobe. Thats all it does.... more or less the same thing.

Miracle

Same principal,different name... VTEC-E as compared to i-VTEC.

toyomatt84

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boilermaker1 &raquo;</TD></TR><TR><TD CLASS="quote">

Depends on how you want to define that. The K20A3 is intake only and operates in a very similar manner. Its got a big lobe and a little lobe on the intake side, when VTEC engages, it puts both valves on the big lift lobe. Thats all it does.... more or less the same thing.</TD></TR></TABLE>

I know that they are almost identical in terms of operation, but if you want to go technical about the definition of the engine types, the D17A6 is the only VTEC-E engine for the 7th gen Civic's.

Miracle

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by toyomatt84 &raquo;</TD></TR><TR><TD CLASS="quote">

I know that they are almost identical in terms of operation, but if you want to go technical about the definition of the engine types, the D17A6 is the only VTEC-E engine for the 7th gen Civic's.</TD></TR></TABLE>

Werd.... You are getting the technical thing down. Now, if I could only get to YOUR level of knowledge about wheels.

TN90accord

Wait, so the D17A2 switches between 12 valve and 16 valve operation, but is not VTEC-E? I thought that's what VTEC-E was? I see how the K20A3 motor would be classified as iVTEC, but shouldn't the D17A2 be classified as VTEC-E?

After posting this I re read those post. So the D17A2 has a Low rpm lobe and a high rpm lobe, and when VTEC engages it goes from 12 valve low rpm to 16 valve high rpm? If so I see what you're saying about it not being VTEC-E.


Modified by TN90accord at 2:33 PM 11/2/2006

Miracle

No, the D17A2 has the traditional VTEC, it just is not the same style, as it only increases duration on the intake valves.

VTEC-E is used only on the D17A6, fouind in the 7th Gen Civic HX.

TN90accord

Please re read my previous post and tell me if that's correct.

Miracle

The D17A2 VTEC, is VTEC because it increases the Lift AND duration of the intake valves. A VTEC-E motor only increases the amount of intake valves that operate... Like the K20A3, and the D17A6.