the math needs answer

[TetanusShot]

Thinking more about this (thanks pops), I'd bet no one uses this equation as it only considers static loading in a highly dynamic event.

I think its kind of neat to see load on a piston. It does look like static loading on the surface but when you pick a tq number to plug in the equation, its at a given rpm for that tq number even though the rpm isn't put into the equation. You're right though, who knows where this came from and who uses it, all the losses from friction put the real numbers way off anyway.

And they say I'm wound up too tight geez, guys this isn't moparts just have a conversation and respect the opinion who cares if it's nuts or nutz?

That's the nice thing about math. There aren't opinions, only right answers and wrong answers. I shouldn't have gotten all worked up in the first place though. Sorry RJRENTON, maybe you know some things about this that I don't and can set me straight.

 

[HT413]

I think its kind of neat to see load on a piston. It does look like static loading on the surface but when you pick a tq number to plug in the equation, its at a given rpm for that tq number even though the rpm isn't put into the equation. You're right though, who knows where this came from and who uses it, all the losses from friction

Even though you can find the force at a given angle, I still is a static loading that you'd find, as if the crank is motionless at that given angle. The dynamic loading, harmonics and shock loading far exceed the static loading, especially at high rpm's where the piston is coming back around 100-150 times per second, so this equation has little practical value.

Though to your point, I find this stuff fun too and I'm fighting off the temptation to derive it myself to check it and play with it a bit lol. Maybe tonight before I knock off.

- - - Updated - - -

Here's a bit of what I'm talking about - 190 page analysis of the dynamic loading of a connecting rod.

https://www.forging.org/system/files/field_document/DynamicLoadAnalysis.pdf

 

[TetanusShot]

Cool! thanks for the link

 

[HT413]

Cool! thanks for the link

No problemo. Here's a cool graph that shows stresses vs crank angle at 6000 rpm's vs 12,000 rpm's. This is for a 5.4L v8, didn't catch the make though. Kinda cool!

 

[Pops1967GTX]

 

[DeltaV]

None. It's a Chevy and all of the teeth on A will shear off instantly.

 

[RJRENTON]

I think its kind of neat to see load on a piston. It does look like static loading on the surface but when you pick a tq number to plug in the equation, its at a given rpm for that tq number even though the rpm isn't put into the equation. You're right though, who knows where this came from and who uses it, all the losses from friction put the real numbers way off anyway.

That's the nice thing about math. There aren't opinions, only right answers and wrong answers. I shouldn't have gotten all worked up in the first place though. Sorry RJRENTON, maybe you know some things about this that I don't and can set me straight.

Thanks for the compliment but what HT413 said and the link explains the premise. I sgree with his analysis....its all about the dynamics (in actual operation) plus the static load factors. Rod lengths and rod angularity play an important factor in the calculations in addition to reciprocating weight and rpm of the mass. Its not simply explained.
BOB RENTON

 

[Ceedawg]

Heck I'm still looking for the sbc rod pic!
The math I know is 1+1=3 or more (twins, triplets)

 

[mopar 3 B]

Heck I'm still looking for the sbc rod pic!
The math I know is 1+1=3 or more (twins, triplets)

It took a couple of mathematicians and a million to prove that one.

 

[Scott Engelhardt]

My head hurts looking at it. I say keep the alphabet out of math!

 

[coronet68mx]

Thats what I meant to say.....

 

[coronet68mx]

View attachment 282499

Say what...

 

[Under Pressure]

It is cool stuff to read, but for me it’s,
AIR+FUEL+SQUEEZE+IGNITE=BAMX8= Hell yes

 

[Pops1967GTX]