Re: ___ Does V-Tec get better mileage at ALL speeds ? ?
 

On Mon, 1 Mar 2004 19:47:06 +0000 (UTC), mph@wopr.caltech.edu (Matthew
Hunt) wrote:

>In article <10474lehgvh649b@corp.supernews.com>,
>Al Smith <ecarecar@yahoo.com> wrote:
>
>> V-Tec gives an engine two cam shafts - a high speed and low speed cam shaft.
>> Each cam shaft is optimized for its own speed range.
>
>No, it gives the engine additional cam *lobes* for high engine speeds.
>There are both SOHC and DOHC varieties of VTEC, and on the DOHC variety,
>there's one shaft for the intake valves, and one for the exhaust valves,
>like a normal DOHC engine. There are low-speed and high-speed lobes on
>each camshaft.

There are now so many variations on Honda's VTEC, it's getting difficult to
give a single characterization - everything from the economy-minded VTEC-E
to performance oriented and everything in between. Until the K-Series
engines, AFAIK the DOHCs did have variable lift on both inlet and exhaust
but now we have variations where, e.g. the RSX engine (K20A ?) has variable
lift on only the intake and the RSX-S(K20C or is it K20A2?) has it on both
cams.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

Re: ___ Does V-Tec get better mileage at ALL speeds ? ?
 

On Mon, 1 Mar 2004 19:47:06 +0000 (UTC), mph@wopr.caltech.edu (Matthew
Hunt) wrote:

>In article <10474lehgvh649b@corp.supernews.com>,
>Al Smith <ecarecar@yahoo.com> wrote:
>
>> V-Tec gives an engine two cam shafts - a high speed and low speed cam shaft.
>> Each cam shaft is optimized for its own speed range.
>
>No, it gives the engine additional cam *lobes* for high engine speeds.
>There are both SOHC and DOHC varieties of VTEC, and on the DOHC variety,
>there's one shaft for the intake valves, and one for the exhaust valves,
>like a normal DOHC engine. There are low-speed and high-speed lobes on
>each camshaft.

There are now so many variations on Honda's VTEC, it's getting difficult to
give a single characterization - everything from the economy-minded VTEC-E
to performance oriented and everything in between. Until the K-Series
engines, AFAIK the DOHCs did have variable lift on both inlet and exhaust
but now we have variations where, e.g. the RSX engine (K20A ?) has variable
lift on only the intake and the RSX-S(K20C or is it K20A2?) has it on both
cams.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

Re: ___ Does V-Tec get better mileage at ALL speeds ? ?
 

On Mon, 1 Mar 2004 19:47:06 +0000 (UTC), mph@wopr.caltech.edu (Matthew
Hunt) wrote:

>In article <10474lehgvh649b@corp.supernews.com>,
>Al Smith <ecarecar@yahoo.com> wrote:
>
>> V-Tec gives an engine two cam shafts - a high speed and low speed cam shaft.
>> Each cam shaft is optimized for its own speed range.
>
>No, it gives the engine additional cam *lobes* for high engine speeds.
>There are both SOHC and DOHC varieties of VTEC, and on the DOHC variety,
>there's one shaft for the intake valves, and one for the exhaust valves,
>like a normal DOHC engine. There are low-speed and high-speed lobes on
>each camshaft.

There are now so many variations on Honda's VTEC, it's getting difficult to
give a single characterization - everything from the economy-minded VTEC-E
to performance oriented and everything in between. Until the K-Series
engines, AFAIK the DOHCs did have variable lift on both inlet and exhaust
but now we have variations where, e.g. the RSX engine (K20A ?) has variable
lift on only the intake and the RSX-S(K20C or is it K20A2?) has it on both
cams.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

Re: ___ Does V-Tec get better mileage at ALL speeds ? ?
 

George Macdonald <fammacd=!SPAM^nothanks@tellurian.com> wrote:
> There are now so many variations on Honda's VTEC, it's getting difficult to
> give a single characterization - everything from the economy-minded VTEC-E

My 2003 civic Hybrid has VTEC for the "cylinder idling system". As far as
I know, it has nothing to do with performance. It just shuts down three
sets of valves during coasting.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8-122.5

Re: ___ Does V-Tec get better mileage at ALL speeds ? ?
 

George Macdonald <fammacd=!SPAM^nothanks@tellurian.com> wrote:
> There are now so many variations on Honda's VTEC, it's getting difficult to
> give a single characterization - everything from the economy-minded VTEC-E

My 2003 civic Hybrid has VTEC for the "cylinder idling system". As far as
I know, it has nothing to do with performance. It just shuts down three
sets of valves during coasting.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8-122.5

Re: ___ Does V-Tec get better mileage at ALL speeds ? ?
 

George Macdonald <fammacd=!SPAM^nothanks@tellurian.com> wrote:
> There are now so many variations on Honda's VTEC, it's getting difficult to
> give a single characterization - everything from the economy-minded VTEC-E

My 2003 civic Hybrid has VTEC for the "cylinder idling system". As far as
I know, it has nothing to do with performance. It just shuts down three
sets of valves during coasting.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8-122.5

Re: ___ Does V-Tec get better mileage at ALL speeds ? ?
 

George Macdonald <fammacd=!SPAM^nothanks@tellurian.com> wrote:
> There are now so many variations on Honda's VTEC, it's getting difficult to
> give a single characterization - everything from the economy-minded VTEC-E

My 2003 civic Hybrid has VTEC for the "cylinder idling system". As far as
I know, it has nothing to do with performance. It just shuts down three
sets of valves during coasting.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8-122.5