Simple explanation of vtec?
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From: Baltimore area
Thanks again guys. I wasn't looking for a real detailed answer. I kind of have the picture now. I would still be interested in knowing the crossover points for this '03, 2.4 motor if anyone has that info.
I'll also do a search.
I'll also do a search.
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YES i-VETC is regular VETC + variable valve timing. Look it up in the "how things work" as Slen suggests. Toyota's VVTL-i works similarly. Toyota came out with it for the 2000 Celica to get the jump on Honda with the doch VETC in the GSR and ITR. Honda countereed in 2001 with i-VETC in the RSX.
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From: 916
Originally posted by 2000Prelude
YES i-VETC is regular VETC + variable valve timing. Look it up in the "how things work" as Slen suggests. Toyota's VVTL-i works similarly. Toyota came out with it for the 2000 Celica to get the jump on Honda with the doch VETC in the GSR and ITR. Honda countereed in 2001 with i-VETC in the RSX.
YES i-VETC is regular VETC + variable valve timing. Look it up in the "how things work" as Slen suggests. Toyota's VVTL-i works similarly. Toyota came out with it for the 2000 Celica to get the jump on Honda with the doch VETC in the GSR and ITR. Honda countereed in 2001 with i-VETC in the RSX.
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Isn't VTEC amazing? And to think, this kind of technology existed in early 90's and now many manufacturer's have their version of VTEC...
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I think VTEC is kind of unique. Variable valve timimg, however, isn't. Most manufactureres have some sort of variable valve timing now. Again variable valve timing and VETC are not the same things! VETC actually involves a high performance camshaft lobe that is used when the VETC crossover point is reached and oil pressure forces the rocker arms together causing them to follow the high performance cam lobes (my description is not the best, but this is what in effect happens). So with VETC it is like you have a choice of two different camshafts.
Variable valve timing involves a device that advances or retards the camshaft timing by "twisting" the camshaft to a more advanced (or greater slope) portion of the cam, thereby opening the valve further than it would normally be.
Honda's new i-VETC and Toyota's VVTL-i systems basically combine a form of VETC with variable valve timing.
Variable valve timing involves a device that advances or retards the camshaft timing by "twisting" the camshaft to a more advanced (or greater slope) portion of the cam, thereby opening the valve further than it would normally be.
Honda's new i-VETC and Toyota's VVTL-i systems basically combine a form of VETC with variable valve timing.
hermit
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From: san diego
Originally posted by 2000Prelude
I think VTEC is kind of unique. Variable valve timimg, however, isn't. Most manufactureres have some sort of variable valve timing now. Again variable valve timing and VETC are not the same things! VETC actually involves a high performance camshaft lobe that is used when the VETC crossover point is reached and oil pressure forces the rocker arms together causing them to follow the high performance cam lobes (my description is not the best, but this is what in effect happens). So with VETC it is like you have a choice of two different camshafts.
Variable valve timing involves a device that advances or retards the camshaft timing by "twisting" the camshaft to a more advanced (or greater slope) portion of the cam, thereby opening the valve further than it would normally be.
Honda's new i-VETC and Toyota's VVTL-i systems basically combine a form of VETC with variable valve timing.
I think VTEC is kind of unique. Variable valve timimg, however, isn't. Most manufactureres have some sort of variable valve timing now. Again variable valve timing and VETC are not the same things! VETC actually involves a high performance camshaft lobe that is used when the VETC crossover point is reached and oil pressure forces the rocker arms together causing them to follow the high performance cam lobes (my description is not the best, but this is what in effect happens). So with VETC it is like you have a choice of two different camshafts.
Variable valve timing involves a device that advances or retards the camshaft timing by "twisting" the camshaft to a more advanced (or greater slope) portion of the cam, thereby opening the valve further than it would normally be.
Honda's new i-VETC and Toyota's VVTL-i systems basically combine a form of VETC with variable valve timing.
Originally posted by Snoopy
VTEC!!!1~
VTEC!!!1~
VTEC man, look under the hood of your 2000 Prelude
Oh and you mispelled DOHC also. (Dual Over Head Cams) :doh:
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You mean me????:naughty: I would never misspell anything 
I'm having some problems typing this past week because I had an oversize picture window slam shut on my hand. My "fawk" finger is bandaged up and my right hand is sprianed. So any misspellings I'm sorry for. It's a little hard to type in this condition
I'm having some problems typing this past week because I had an oversize picture window slam shut on my hand. My "fawk" finger is bandaged up and my right hand is sprianed. So any misspellings I'm sorry for. It's a little hard to type in this condition
hermit
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From: san diego
Originally posted by 2000Prelude
You mean me????:naughty: I would never misspell anything
I'm having some problems typing this past week because I had an oversize picture window slam shut on my hand. My "fawk" finger is bandaged up and my right hand is sprianed. So any misspellings I'm sorry for. It's a little hard to type in this condition
You mean me????:naughty: I would never misspell anything
I'm having some problems typing this past week because I had an oversize picture window slam shut on my hand. My "fawk" finger is bandaged up and my right hand is sprianed. So any misspellings I'm sorry for. It's a little hard to type in this condition
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From: Ann Arbor, MI
http://auto.howstuffworks.com/camshaft3.htm
Variable Valve Timing
There are a couple of novel ways by which carmakers vary the valve timing. One system used on some Honda engines is called VTEC.
VTEC (Variable Valve Timing and Lift Electronic Control) is an electronic and mechanical system in some Honda engines that allows the engine to have multiple camshafts. VTEC engines have an extra intake cam with its own rocker, which follows this cam. The profile on this cam keeps the intake valve open longer than the other cam profile. At low engine speeds, this rocker is not connected to any valves. At high engine speeds, a piston locks the extra rocker to the two rockers that control the two intake valves.
Variable Valve Timing
There are a couple of novel ways by which carmakers vary the valve timing. One system used on some Honda engines is called VTEC.
VTEC (Variable Valve Timing and Lift Electronic Control) is an electronic and mechanical system in some Honda engines that allows the engine to have multiple camshafts. VTEC engines have an extra intake cam with its own rocker, which follows this cam. The profile on this cam keeps the intake valve open longer than the other cam profile. At low engine speeds, this rocker is not connected to any valves. At high engine speeds, a piston locks the extra rocker to the two rockers that control the two intake valves.