question about over revving

[H311RA151N]

Then i stand corrected
I seen this and was like damn i need one of those
Show how much i get fooled into shit

I would have guessed it was real also. So dont feel bad.

The second time I watched it I picked up on a few thnigs and knew it was fake for sure.

[H311RA151N]

Can I ask a newb q?

How come they don't make motors for dd Honda's that rev that high lol?

Idk the S2k limit, but im fairly certain its not even close lol.

Again not sure about the NSX limit, but its maybe a little closer...

but 17k good god.

Maybe it's not necessary?

Idk I think it would be cool!

I forgot to mention that the early 90s Honda CBR250R redlined at like 19,000 or something crazy like that. I rode one once and it was faster than the Buell Blast 500 I had at the time.

I bought a Triumph Daytona 675 which was one of their wicked triple series engines (3 cylinders). My friend who had the CBr250R would smoke me going through town on it because it was so light and agile.

[Ralphie]

Ya that's my guess as well.

Ya I would have guessed 9k for s2k and 10 for nsx.

In either case, that's worlds away from 17k LOL.

Im sure above 12k on a bike is phenomenal, but I would never ride one so Ill never know lol.

[H311RA151N]

Ya that's my guess as well.

Ya I would have guessed 9k for s2k and 10 for nsx.

In either case, that's worlds away from 17k LOL.

Im sure above 12k on a bike is phenomenal, but I would never ride one so Ill never know lol.

Yeah 17k is way up there. You really realize it when you’re on a bike.

I honestly think if you could supply enough fuel and air appropriately that a somewhat healthy F22A could see 10,000rpm for a few seconds as long as it was eased into it.

[Ralphie]

Yeah 17k is way up there. You really realize it when you’re on a bike.

I honestly think if you could supply enough fuel and air appropriately that a somewhat healthy F22A could see 10,000rpm for a few seconds as long as it was eased into it.

I don't doubt that.

F series is pretty fucking strong.

Hell plenty of people out their on poorly maintained ones that beat on them and they take it and smile.

[toycar]

Piston speed is the reason that larger engines cannot rev that high.


The MPS(meters per second) of travel of a piston can only be so fast before it becomes unmanageable. The length of the stroke dicatates a lot when considering how high you can safely rev an engine.

The highest production piston speed vehicle is the s2k, and it only reaches speeds of like 23MPS.


Bikes, even though they rev to 17,000 rpms have such a short stroke that piston speeds are manageable. This is also why v6-v8 F1 engines are only 2 liters. Little to NO stroke in the design = hardly any displacement but a rev monster.

A ZX6r has a bore of 68mm and a stroke of 43.8mm compared to the f22 in our cb's 85mm bore and 95mm stroke. That means the crank travels more than twice as far in the F22 engine vs the zx6r per revolution. So, the zx6r can easily rev(revolutions per minute) twice as high while keeping the same piston speeds since the length of the stroke directly dictates the distance the piston travels, and that length is less than half of the stroke of an f22.

The bike makes 128HP and 48 lb/ft of torque. The bike only weighs a bit over 400lbs, so that is plenty of torque to move it. A civic that makes 95hp wouldn't even move if you tried powering it with the same motorcycle engine. Even though it makes more HP, there isn't enough torque to do anything with. Since HP is only a measure of how often TQ can be duplicated, really, HP means nothing. Its merely a measure of efficiency. TQ is the actual measure of power.

And the reason daily drivers don't do this is that they need off the line powa. So, stroke is more important than rev. More stroke generates more torque.



The phrase "Work done over time" comes to mind here. In that phrase "work" represents TQ and "Over time" represents HP.

The shorter the stroke, the faster the cycle is able to be duplicated over time. Since HP is a measure how fast TQ can be reproduced, a super short stroke generates minimal torque and TONS of HP. Most F1 cars really aren't that fast off the line for todays racing standards. This is because of the lack of stroke.


Its also a BITCH to get these cars to start, since there is minimal cylinder pressure when you crank the engine over. I've never personally owned or raced an F1, but my uncle has a car with a flat top 6 in it and the scene has been a part of my life for decades.

[deevergote]

Yeah 17k is way up there. You really realize it when you’re on a bike.

I honestly think if you could supply enough fuel and air appropriately that a somewhat healthy F22A could see 10,000rpm for a few seconds as long as it was eased into it.

You'd experience valve float for certain, even if the bottom end held.

[RyanD]

Piston speed is the reason that larger engines cannot rev that high.


The MPS(meters per second) of travel of a piston can only be so fast before it becomes unmanageable. The length of the stroke dicatates a lot when considering how high you can safely rev an engine.

The highest production piston speed vehicle is the s2k, and it only reaches speeds of like 23MPS.


Bikes, even though they rev to 17,000 rpms have such a short stroke that piston speeds are manageable. This is also why v6-v8 F1 engines are only 2 liters. Little to NO stroke in the design = hardly any displacement but a rev monster.

A ZX6r has a bore of 68mm and a stroke of 43.8mm compared to the f22 in our cb's 85mm bore and 95mm stroke. That means the cranks travels more than twice as far in the F22 engine vs the zx6r per revolution. So, it can easily rev(revolutions per minute) twice as high while keeping the same piston speeds.

The bike makes 128HP and 48 lb/ft of torque. The bike only weighs a bit over 400lbs, so that is plenty of torque to move it. A civic that makes 95hp wouldn't even move if you tried powering it with the same motorcycle engine. Even though it makes more HP, there isn't enough torque to do anything with. Since HP is only a measure of how often TQ can be duplicated, really, HP means nothing. Its merely a measure of efficiency. TQ is the actual measure of power.

And the reason daily drivers don't do this is that they need off the line powa. So, stroke is more important than rev. More stroke generates more torque.



The phrase "Work done over time" comes to mind here. In that phrase "work" represents TQ and "Over time" represents HP.

The shorter the stroke, the faster the cycle is able to be duplicated over time. Since HP is a measure how fast TQ can be reproduced, a super short stroke generates minimal torque and TONS of HP. Most F1 cars really aren't that fast off the line for todays racing standards. This is because of the lack of stroke.


Its also a BITCH to get these cars to start, since there is minimal cylinder pressure when you crank the engine over. I've never personally owned or raced an F1, but my uncle has a car with a flat top 6 in it and the scene has been a part of my life for decades.

so i guess what i said was a cliffnotes of what you said?

[BurtonRiderT6]

TQ is not really needed in circuit racing since there is only a few times where you come to a complete stop, and even then you can't accelerate over a certain speed limit. So having high HP and low TQ is ideal when circuit racing to keep you in the powerband found in the high revs. I say low TQ which in reality is still more than most cars make but it's considerably less when compared to the HP it makes.

TQ = low end
HP = top end

[toycar]

so i guess what i said was a cliffnotes of what you said?

Yes and no.


Lol.


Piston speed is the determining factor here. Stroke and RPM dictate piston speed. Valve trains could be built to allow shit to rev to 30,000 RPM's if the engine could allow. Its really about stroke length, RPM and piston speed.

[ferenza]

So would high revs be good for auto x or circuit racing?

[H311RA151N]

I don't doubt that.

F series is pretty fucking strong.

Hell plenty of people out their on poorly maintained ones that beat on them and they take it and smile.

The F is one tough mofo. That much is certain.

You'd experience valve float for certain, even if the bottom end held.

There was a guy in town a few years ago with a F22B CD5, it had cams and some other stuff done. He was getting ready to boost it IIRC. Anyways, he pulled out his laptop one day and was showing me some of his data logging software and whatnot. he showed me this graph or page where he said he missed a shift and it set his max RPM to like 8,821RPM or something like that just shy of 9k.

The F don’t need any help by me or anyone boasting for it but I honestly think that with valve float and everything else that can go wrong factored, the old bastards would take it. Against the odds for sure but I would still expect it.

I have seen some Fs just have the hell beat out of them over and over again with no remorse and not even faze it. I had a teacher in school seize one up, I forget how, but he seized it up hard. He pulled the plugs out and let some marvel mystery oil sit in the cylinders for a few days and got it freed up. That was almost 10 years ago and he still drives it every day, I see it in the parking lot on my way through town. I though I seen it at the gas station the other day and a puff of smoke came out as he pulled away but Im not sure. I imagine it damaged it but it sure as hell still runs.

So would high revs be good for auto x or circuit racing?

I was thinking about that myself. I cant/wont do an engine swap on my AutoX solo CB because it puts me in a class where I wont have a chance. But I was thinking about the F20B mated it an F trans with an LSD, an H23 trans with an LSD or even the LSD F20B trans and that would combined with being able to rev the shit out of it so a person could keep it in gear a long time. Of course there is more to it than that (vtec kicking in, the tracks are all different and so on) but thats the base of my idea.