On Sun, 31 May 2015 15:22:28 -0400,
cl...@snyder.on.ca wrote:
>On Sun, 31 May 2015 13:56:02 -0400, Ed Huntress
><
hunt...@optonline.net> wrote:
>
>>On Sun, 31 May 2015 17:01:22 +0000 (UTC), John Doe
>><alway...@message.header> wrote:
>>
>>>Google Groups spam/troll...
>>
>>--
>>>jon_banquer <jonbanquer
yahoo.com> wrote in news:4037cf98-257b-49c5-a5f3-dd32a241ace8
googlegroups.com:
>>
>>>> The fifth race this season for Daytona Prototypes is Detroit and once again pushrod reality has kicked slow eddy right in the nuts:
>>>>
>>>> Chevy pushrod motors have claimed not only pole position in Detroit (4 out of 5 poles this year have been won by Chevy pushrod motors)but have taken the second and third positions over the Ford EcoBoost as well.
>>>>
>>>> slow eddy continues to show just how little he really knows about race engines.
>>.>
>>>>
https://www.youtube.com/watch?v=kr0AXN1IPUc
>>>>
>>
>>Jesus, what a twit. So two of the four 5.5 liter Brontosaurus truck
>>engines beat the Honda and (lone) Ford 3.5 liter OHCs, and two of the
>>Brontosauri finished behind them.
>>
>>As several of us tried to explain to Bonkers years ago, when you need
>>5.5 liters to beat 3.5 liters, claiming you're more "advanced," you
>>aren't doing very well. That's a pyrrhic victory.
>>
>>Bonkers apparently doesn't understand this.
> It's called different horses for different courses.OHC engines tend
>to do better where high RPMs are an advantage, particulalarly when 4
>valves are required to get adequate breathing. They tend to have a lot
>less advantage in slower turning high torque engines.
Right. Chevy says that OHC on a small-block, in street tune, gives you
about 10% more horsepower. (They offered a small-block with OHC for a
year or two.) In racing, it can be a great deal more, but the big V8
engines are basically piston-speed limited, so an engine that big is
not going to get as much advantage as a smaller one that is
valve-speed limited.
>
>What you need to remember is engined run on air. The more air you can
>put through them, the more power you can get out of them. The engine
>doesn't really care how big the gulps of air are - a 1 liter engine at
>10,000 rpm breathes as much air as a a 5 liter engine at 2000 RPM, and
>should theoretically produce about the same horsepower (friction and
>pumping losses not factored in)
>A 3.7 liter engine running 1 atmosphere of boost consumes the same
>amount of air as a 7.4 liter engine at the same RPM, and should
>provide about the same horsepower output.
Assuming the 7.4 liter NA engine has no intake or exhaust tuning. In
racing, they all do. So boosting one bar above atmospheric, all else
being equal, does not double your horsepower.
>
>Don't expect the little engine to haul logs or plough dirt like the
>big one, and don't expect it to stick together as long while putting
>out the same horsepower.
But this one does. Here's an example:
http://tinyurl.com/6ajnvgn
The strength of these smaller engines, SI or diesel, has recently
surpassed all of the conventional rules-of-thumb.