'99 323i 12 or 24 valve ?

Dave Plowman (News) wrote:

> In article >,
> Nate Nagel > wrote:
>
>>And before you ask, yes, there is a
>>good reason why some engines still have pushrods, you can get a lower
>>overall height without an overhead cam. That was one of the reasons
>>given for retaining the single central camshaft and pushrods for the new
>>Corvette motor.
>
>
> It's also cheaper. ;-)
>

Probably true. However, I do remember reading somewhere that the
possibility of an OHC engine was discussed, but they were concerned
about hood clearance - didn't want to lose that "trademark" ultra-low
hood, you know.

nate

--
replace "fly" with "com" to reply.
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"Jeff Strickland" > wrote
> That is only 2 per cylinder, I do not recall any motor made today that
> uses that technology, with the possible exception to the Viper. The
> Viper's V10 only has 20 valves. Most engines today use 3 or more valves
> per cylinder, this facilitates a better blended mixture reaching the
> combustion chamber, which results in better fuel economy and cleaner
> burning.

To add to the 2-valve list: Chrysler/Dodge (Daimler) Hemi.

Floyd

fbloogyudsr wrote:
> "Jeff Strickland" > wrote
>> That is only 2 per cylinder, I do not recall any motor made today
>> that uses that technology, with the possible exception to the Viper.
>> The Viper's V10 only has 20 valves. Most engines today use 3 or more
>> valves per cylinder, this facilitates a better blended mixture
>> reaching the combustion chamber, which results in better fuel
>> economy and cleaner burning.
>
> To add to the 2-valve list: Chrysler/Dodge (Daimler) Hemi.

2 plugs per cyl. though and they're expensive too. :-(

Jeff

>
> Floyd

Andrew Thomas wrote:
>
> Um, GM's 5.7 V8? Quite a populous engine .

[Hey, if nobody else is going to take it ...]

OK, Andy, how many people *can* live in a Chevy engine?
--
C.R. Krieger
(Been there; done that)

In article >,
Nate Nagel > wrote:
> >>And before you ask, yes, there is a good reason why some engines
> >>still have pushrods, you can get a lower overall height without an
> >>overhead cam. That was one of the reasons given for retaining the
> >>single central camshaft and pushrods for the new Corvette motor.
> >
> >
> > It's also cheaper. ;-)
> >

> Probably true. However, I do remember reading somewhere that the
> possibility of an OHC engine was discussed, but they were concerned
> about hood clearance - didn't want to lose that "trademark" ultra-low
> hood, you know.

No expert on US engines - apart from the now sadly departed pushrod
Buick/Rover unit, but is the new Corvette engine an all new design with
pushrods? Or simply an updated version of an older unit?

--
*One nice thing about egotists: they don't talk about other people.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

> In article >,
> Nate Nagel > wrote:
>
>>>>And before you ask, yes, there is a good reason why some engines
>>>>still have pushrods, you can get a lower overall height without an
>>>>overhead cam. That was one of the reasons given for retaining the
>>>>single central camshaft and pushrods for the new Corvette motor.
>>>
>>>
>>>It's also cheaper. ;-)
>>>
>
>
>>Probably true. However, I do remember reading somewhere that the
>>possibility of an OHC engine was discussed, but they were concerned
>>about hood clearance - didn't want to lose that "trademark" ultra-low
>>hood, you know.
>
>
> No expert on US engines - apart from the now sadly departed pushrod
> Buick/Rover unit, but is the new Corvette engine an all new design with
> pushrods? Or simply an updated version of an older unit?
>

Somewhere in between. I don't believe a single part will interchange
with a '55 Chev motor, but I believe the bellhousing pattern is still
the same and at least as of a couple years ago the holes were still
drilled and tapped for the early motor mounts. Not sure about the
newest iteration. Architecture is very similar but it's been refined
beyond interchanging parts.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

On 18 Jan 2005 13:40:16 -0800, "Andrew Thomas"
> wrote:

>Jeff Strickland wrote:
>> That is only 2 per cylinder, I do not recall any motor made today
>that uses
>> that technology, with the possible exception to the Viper.
>
>Um, GM's 5.7 V8? Quite a populous engine .

There's no replacement for displacement. 8)