Honda Civic DIYs and Civic Tech ChatHonda Civic DIYs and Civic Tech Chat - for the true gearheads! Bring your wrench, it's time for some Honda Civic DIY projects! Questions about problems with your car do NOT go here.
Welcome to civicforums.com!
Welcome to civicforums.com.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to start new topics, reply to conversations, privately message other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join civicforums.com today!
Here is the proof that only one valve opens until VTEC engagement. I tore apart my entire F****** motor to prove you wrong 4drcivic2k1 (and I was doing some other stuff too but you will see that in the DIY section soon). This is at top dead center for cylinder 3.
BTW, why would an intake valve be open at top dead center? That wouldn't run very well now would it?
To remove this ad, register today for free or log in if already registered!
Sponsored Links
To avoid seeing this ad in our forum please register at CivicForums.com
By joining our free community you will have access to post topics, respond to polls, upload content and access many other special features.
and it seems like the lx would be faster having both valves open instead of 1 when vtec is in low cam profile. Does that mean the extra power from the ex only comes from vtec, which nobody ever even uses if you have to floor the car and take it to high rpms. I don't think any average civic owner does that.
but the LX has smaller valves and the cam profiles are not that aggresive. On the EX (VTEC) motor, the non vtec lobe is more aggresive than the Lx simply because it has to the job of both smaller valves do in the non Vetc motors. But yes, almost all of the power gianed by Vtec is in higher RPMs. I made use of it all the time when I had my Civic EX 5 speed. Now that I have an auto though, I take it easy. Every time I floor the car, I imagine the tranny cruching away. Even though I know it won't becasue the tranny for the 4 cylinder Accord is internally the same as the V6 Accord, so if it can handle the 212 ft-lb V6, the 161 ft-lb from my K24 is nothing. But back to my point, I just don't seem to hit those higher rpms with an auto, guess it makes me a "better" driver.
but the LX has smaller valves and the cam profiles are not that aggresive. On the EX (VTEC) motor, the non vtec lobe is more aggresive than the Lx simply because it has to the job of both smaller valves do in the non Vetc motors. But yes, almost all of the power gianed by Vtec is in higher RPMs. I made use of it all the time when I had my Civic EX 5 speed. Now that I have an auto though, I take it easy. Every time I floor the car, I imagine the tranny cruching away. Even though I know it won't becasue the tranny for the 4 cylinder Accord is internally the same as the V6 Accord, so if it can handle the 212 ft-lb V6, the 161 ft-lb from my K24 is nothing. But back to my point, I just don't seem to hit those higher rpms with an auto, guess it makes me a "better" driver.
On the EX, there are only 2 lobes. One per valve. One is bigger than the other. The big one, or "vtec lobe" ALWAYS has one valve riding on it, no matter what. The other lobe, which simply cracks the other intake valve open to keep fuel from puddling behind it ALWAYS has one valve on it. When VTEC engages, both valves follow the single larger lobe.
On the EX, there are only 2 lobes. One per valve. One is bigger than the other. The big one, or "vtec lobe" ALWAYS has one valve riding on it, no matter what. The other lobe, which simply cracks the other intake valve open to keep fuel from puddling behind it ALWAYS has one valve on it. When VTEC engages, both valves follow the single larger lobe.
Yeah Iknow both valves opens, but in non-VTEC mode, more than 80% of the air flow comes from the smaller valve. So my point is that the single smaller valve (with a little help from the bigger valve <- that's the part I left out last time) has to do what both valves in the non-VTEC motor do.
Both valves are the same size. One just opens more.
I'm using my adjectives wrong. by smaller I mean the cam lobe is smaller. Yeah, both valves are the same. Sorry, it's one of those things I know what I'm saying, but I just can't say it correct.
BTW, why would an intake valve be open at top dead center? That wouldn't run very well now would it?
You just don't get cars do you? Top dead center dose not mean that all 4 cylinders are at the top. Two are at the top and two are at the bottom. At to dead center cylinder two and three are at the bottom, one and four are at the top. And I never said anything about the exhaust valves being closed ever. You just hate to admit you were wrong.
On the EX, there are only 2 lobes. One per valve. One is bigger than the other. The big one, or "vtec lobe" ALWAYS has one valve riding on it, no matter what. The other lobe, which simply cracks the other intake valve open to keep fuel from puddling behind it ALWAYS has one valve on it. When VTEC engages, both valves follow the single larger lobe.
You stated that it was the top dead center for CYLINDER 3. THAT WOULD IMPLY THAT THE PISTON IS AT THE TOP OF ITS STROKE. THAT WOULD MEAN THAT THE VALVE SHOULD BE CLOSED COMPLETELY OR JUST STARTING TO OPEN, depending on if it is compression or intake stroke. If you have a valve completely open at TDC you will have bigger problems than VTEC engaging.
by smaller I mean the cam lobe is smaller. Yeah, both valves are the same. Sorry, it's one of those things I know what I'm saying, but I just can't say it correct. 
