Limiting factor for RPMs?

[TC]

no one ever argued that a short stroke motor isn't capable of higher sustained RPM, however the wiki you just posted has nothing to do with your idea about "rpm faster" . Acceleration & Velocity are two different things, but I guess your brilliant physics mind can't figure that out.....

the article also notes that larger bore allows for larger valves, but isn't that part of the "valve shrouding fantasy" as you put it earlier??

but I guess we should all just accept that Rick Santos only used to win because his car would "rpm faster" than the competition....... I'll go get that little honda S2000 motor out now cause it should dominate the world......

Did you ever think that the more HP you make the faster the crank spins........

[TC]

TC why don't you and your buddy Rick build engines with your concepts incorporated and show us all we don't know anything. How about starting with a 2" stroke that should be really killer in your Monte.

Don't be dragging my friend Rick into this, these are purely my theories........ Though Rich does like short stroke big bore small blocks....... Him and I are both from the old school world of high winding small blocks....... Put it this way I built my 406 in a time when everyone said they were junk and you couldn't rpm them, now everyone wants to build a big cubic inch small block.......... Now I'm going to try the other way around and build myself a short stroke small block with turbos........ Thing is I'm going to make 900+lb-ft of torque, so is stroke really a concern??...... What I want is a motor that will hit 8 grand on the drop of a dime........ And I'd rather not waste time and energy waiting for a long stroke to make it laps.......

[Bob Holmes]

What a train wreck.

Given your unconventional views, TC, why don't you go ahead and build it and prove your theories. Instead of talking about them. You'll be the "DeltaWing" of engine builders. Whooping peoples' asses tends to shut them up, so spend the time in the garage building the whoopass machine, instead of taking time here.

I think it would be a solution that would make all of us happy.

[ksj2]

My head hurts.

[jcharliem]

...Put it this way I built my 406...

Ahh yes... the infamous 406 that has yet to fire.

[TC]

Ahh yes... the infamous 406 that has yet to fire.

That reminds me I should go turn it over a couple of times........

[chevy3100truck]

Did you ever think that the more HP you make the faster the crank spins........

really? I hadn't thought of that! ;) now back to where you said that a 500HP car with a longer stroke would not be as quick as a 500HP car with a short stroke....

[JeffMcKC]

Yogi Berra :


"In theory there is no difference between theory and practice. In practice there is".

[JeffMcKC]

That reminds me I should go turn it over a couple of times........

Be Careful of your Back LMAO!

[dieselgeek]

really? I hadn't thought of that! ;) now back to where you said that a 500HP car with a longer stroke would not be as quick as a 500HP car with a short stroke....

So what about those stationary engines that make huge HP at super low RPMs? His whole premise is so bad, there are fourth graders with better understanding of the physics involved.

[MR P-BODY]

If you look at how the HP readings are done (by product of torque)taken in a
one minute period... the higher the RPM it will have more pulses in that period
(every pulse... cyl firing) it will make more power IF the engine is set up to do so...
Reier/Morrison(sp) thinks so also if you wanted to read some of there stuff....
my one race engine makes peak HP at 8200 rpm but I have had it up to 9600
to see if it made any more power... it didnt because of the cam I run... to the OP
question... best way to to put it on a dyno and see where it makes the best power
and dont go higher than 10% more(most racers cross the traps at 10% higher revs
than peak power)

[TheSilverBuick]

A lesson to TC I was giving in 2008! Hasn't learned yet.

Elementary physics, horsepower is a rating of work over time, 500hp regardless of how it's generated accomplishes the same amount of work. One works at a lower rpm range than the other, so adjusting gearing accordly to optimize the rpm band and given identical weight (and traction) the cars would accomplish the same amount of work over the same distance at the same time. I.E. an optimized 500hp 4-cyl. against an optimized 500hp 8-cyl is going to give identical results.

2009.

TC, seriously, take at least a highschool chemistry and physic's class, I'd say elementary if they offered it. This is chemistry and physics 101. ALL, I mean, ALL, combustion has emissions, the only thing that can generates energy and leave no mass (emissions) is Nuclear Fission, and we are far from getting to the point of complete destruction of mass, there is always a remainder. Zero emissions comes with the Perpetual Motion Machine (tomorrow's topic?).

I stopped looking after that. I'm sure there is an annual one for 2010 and 2011.

A quote from me from 2011 responding to a different type of physic's question, but sums up what I think about "gut feelings" and "expectations" on physics.

June 1st 2011

The laws of physics surprisingly aren't as intuitive as they often seem, and what seems improbable in a lot of cases is usually explained by counter-intuitive physics. I learned plenty of that in a year of physic's, I couldn't believe how often my gut feeling on how something would work or turn out was simply wrong.

TC is loaded with what I call "Pot Logic". I coined that term way back in 2000 from a bunch of friends of mine that have the same problem as TC. They would get high, think the world HAS to operate a certain way, though with simple math, physics, etc it would prove them wrong, they would refuse to believe it because a long convoluted drawn out way they can make it "make sense in their mind". Reality be damned. I still have one friend that still operates on that logic. Fustrating as hell to debate or argue with him because he makes no valid points and insists they are valid. So now I just laugh at him, which pisses him off, but IMO it beats me getting pissed off instead.

[dieselgeek]

If you look at how the HP readings are done (by product of torque)taken in a
one minute period... the higher the RPM it will have more pulses in that period
(every pulse... cyl firing) it will make more power IF the engine is set up to do so...

There are a TON more variables in reality that aren't being mentioned here. We cannot simply say "if the engine spins more RPM it makes more power" - why? because nobody's mentioned the all important Volumetric Efficiency!

If your engine can spin another 1200rpm but the volumetric efficiency drops off such that the product of VE and RPM is LOWER at that high RPM, then you are making LESS power. Not more. Power is not a simple function of RPM, ever. I can see why people think about it this way but, it's not how engines work.

[dieselgeek]

these are purely my theories........

You mean, purely yours AND wikipedia, right? Meanwhile, these are not "theories" at all, but hey, let's roll with it. It's not like any of this discussion is going to result in a running engine, ever.

[squirrel]

There are a TON more variables in reality that aren't being mentioned here.

That's why he said "IF the engine is set up to do so..."