carb conversions

[videoarizona]

Guys, I know nothing about what you are both yapping on about...but do know this: My 1960 Bugeye Sprite had a 948cc motor and 40hp. The car came with an owners manual, a racing manual and a small manual that showed how to increase hp. The diagrams in the little manual were nothing more than measurements and plotted lines showing how to grind the intake manifold for smoother and better flow. That's how the British increased the hp on their tiny motors! Nothing else was changed...the CV carbs, the adjustable timing was left alone.

 

So there ya go!

 

And that's the extent of my knowledge.....

[cowpuc]

Hi Puc,

I’m thinking you are mistaking the 5252 as you say from the mathematician?

I have a couple of links below that I think are worth viewing (its short) and the others worth the read. One addresses directly, the others both I think will cause all of us rethink how we consider results.

 

Somewhere around 5000rpms the two curves converse true (not always)but, we aren’t measuring loss we are still in fact measuring gains.

You asked me about tuning for torque instead of HP and if we were in agreement and I said yes, and still agree.

But, until we move past the engine with the mods or the tuning of an engine, dyno is what I think matters, not the measuring of wheel output! This is also where we find the 25% narrowing of Torque equals HP gap and it is to be found at crank shaft output.

I realized during our chat that this line and time over distance;) has become blurred. I think its just one of those parts where time and conversations confused instinct?

Also your days spent building V-twin long winded strokes, influence how you view mods? That doesn’t make you wrong Puc it does upset the 2 curves tho because of volumes in percentage loss over strokes.

 

Put this way, if HP is a result of torque/crank then volume wise twin wins because of stroke (given equal bore dia).. But shorter strokes win higher up the rev range because they complete cycles at faster/shorter stroke times, per revolution! Both have percentage of volume losses around flows and, how flows move thru the engines! When the bottom end is built correctly then increasing volumes above the piston is the next hurtle; one without the other would explain what you allude to in the video for self-destruction of the pistons and crank. Lets not forget that pistons are rocking on a pin while floating between walls, positioned and held by the rings, also floating. If the piston comes off its axis then it will slap increasing heat, increasing expansion and knocking the crank out of balance; which is soon followed by catastrophic failure. Likely you will achieve that fast on a big twin then a four banger because the crank is longer and we can design in compensating strokes! That gets complicated but its there on the four bangers and measured in degrees of the crank levers.

 

I wanted to thank you for forcing me to dig deeper into my off the shelf corners of my experience Puc; I haven’t thought of renovating crankcase area in a very long time, this was a great experience for me to dive further into and express smilingly those very well learned lessons!

 

I didn’t explain my objection to the Variable intake with center carb.

Overlooking angles such as Throttle plate defections and 90* turns , plus valve pressure pluses at either end, there would require one additional butterfly per side per cylinder for the variable intake to be variable.

When closed the air/fuel mix will stall in both high demand intake flow tubes, up till and around peak torque when the butterfly (x2) would open allowing for additional flow through both sides. However the mixture can separate at this stall and fuel will seep past with a likely slightly leaking air flow as the butterfly remains closed before actuated. This will likely cause spotty surging on both cylinders as the fuel makes it way down. (makes sense) is that not what happened to the honda?

Add to this, variable intakes are designed around port injection or direct injection or combos of both. This means that the added wall, floor and ceiling surfaces generate additional friction and flow losses yet increase concentricity but; although average losses are higher, stoichi is not effected yet due to port situated injection and, mapping is a simple compensate, meaning you don't have to go looking for the flow loss it just is what it is! Not so with a carb at the center of the induction.

At least that is how I see it..

 

 

This is in my opinion a good explanation of dyno when used as a build or result tool.

 

 

https://mechanics.stackexchange.com/questions/30142/torque-reduces-gradually-after-certain-rpm

 

This one is a bit longer but read what happens with gear to torque values.

 

https://mechanics.stackexchange.com/questions/25419/what-is-the-difference-between-torque-and-horsepower

 

Look right at the bottom of the Chart the guy is working for.. Do you see it patch? There it is again,,,, 5252

[cowpuc]

Guys, I know nothing about what you are both yapping on about...but do know this: My 1960 Bugeye Sprite had a 948cc motor and 40hp. The car came with an owners manual, a racing manual and a small manual that showed how to increase hp. The diagrams in the little manual were nothing more than measurements and plotted lines showing how to grind the intake manifold for smoother and better flow. That's how the British increased the hp on their tiny motors! Nothing else was changed...the CV carbs, the adjustable timing was left alone.

 

So there ya go!

 

And that's the extent of my knowledge.....

 

I wanna play with that Bugeye so bad I could SCREAM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[videoarizona]

I wanna play with that Bugeye so bad I could SCREAM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

Best I can do for now...sold it about 8 years ago.....sad day that was....

 

1st pic in 1970 here in Arizona. 2nd pic was in Big Springs Texas...on extended leave from Turkey heading to Colorado...

 

 

 

Drool on....I am...sigh...

 

BTW, the Bugeye had 2 SU HS1 Mk1 carbs on it. My first experience at CV type carbs

Edited February 19, 2019 by videoarizona
add

[cowpuc]

Best I can do for now...sold it about 8 years ago.....sad day that was....

 

1st pic in 1970 here in Arizona. 2nd pic was in Big Springs Texas...on extended leave from Turkey heading to Colorado...

 

https://www.venturerider.org/forum/attachment.php?attachmentid=115574https://www.venturerider.org/forum/attachment.php?attachmentid=115575

 

 

Drool on....I am...sigh...

 

ABSOLUTELY STUNNINGLY OUTSTANDING OH SWEET BROTHER OF MINE!!!!:clap2:

 

Except for that part about where you sold it:95:.. Now you got your buddy up here in Michigan sitting here with a great big poochy lip thinkin of how much fun we coulda had going resturant to resturant in that GORGEOUS Bugeye looking for that piece of pie I owe ya:missingtooth:

[Patch]

Guys, I know nothing about what you are both yapping on about...but do know this: My 1960 Bugeye Sprite had a 948cc motor and 40hp. The car came with an owners manual, a racing manual and a small manual that showed how to increase hp. The diagrams in the little manual were nothing more than measurements and plotted lines showing how to grind the intake manifold for smoother and better flow. That's how the British increased the hp on their tiny motors! Nothing else was changed...the CV carbs, the adjustable timing was left alone.

 

So there ya go!

 

And that's the extent of my knowledge.....

 

I found this while looking up the specs, really cool simple car!

 

https://www.conceptcarz.com/s8175/austin-healey-sprite.aspx

[Patch]

Look right at the bottom of the Chart the guy is working for.. Do you see it patch? There it is again,,,, 5252

 

OK Puc same dilemma new approach. I wanted to take some time between to think of how I might express this differently, yup I sometimes think slow.

 

Would you agree that in the mentioned graph, torque is still present past 5000 rpm?

Yes or No

 

Would you also agree that in a naturally aspirated engine, low pressure is the fuel delivery system used to transfer the charge or fill the jug?

Yes or No

 

Would you agree that low pressures alter in direct relation to the throttle angle?

Yes or No

 

Would you agree then, that torque peaks seems to correlate to peak velocity?

Yes or No

 

 

Anyone who would like to, should pile in and consider this an open conversation.

[cowpuc]

OK Puc same dilemma new approach. I wanted to take some time between to think of how I might express this differently, yup I sometimes think slow.

 

Would you agree that in the mentioned graph, torque is still present past 5000 rpm?

Yes or No yep

 

Would you also agree that in a naturally aspirated engine, low pressure is the fuel delivery system used to transfer the charge or fill the jug?

Yes or No nope

 

Would you agree that low pressures alter in direct relation to the throttle angle?

Yes or No yep

 

Would you agree then, that torque peaks seems to correlate to peak velocity?

Yes or No nope

 

 

Anyone who would like to, should pile in and consider this an open conversation. yep

 

[Flyinfool]

OK Puc same dilemma new approach. I wanted to take some time between to think of how I might express this differently, yup I sometimes think slow.

 

Would you agree that in the mentioned graph, torque is still present past 5000 rpm?

Yes or No Yup see below

 

Would you also agree that in a naturally aspirated engine, low pressure is the fuel delivery system used to transfer the charge or fill the jug?

Yes or No Nope see below

 

Would you agree that low pressures alter in direct relation to the throttle angle?

Yes or No Nope see below

 

Would you agree then, that torque peaks seems to correlate to peak velocity?

Yes or No Nope see below

 

 

Anyone who would like to, should pile in and consider this an open conversation. Oh Yea, the more the merrier.

 

It is obvious that torque is present all the way to the top RPM reached, It is declining but still present.

 

It is not low pressure that fills the jug it is the higher pressure of the ambient air pushing the charge in that is doing the filling. Artificially aspirated simply increases that filling pressure. The throttle plate simply blocks the high pressure from pushing charge in.

 

As you go past the torque peak, airflow and thus velocity continue to increase all the way to red line where you stop trying to get more. Peak torque happens at peak efficiency. Peak velocity is way higher than peak efficiency. As the velocity keeps getting higher there are diminishing returns where it starts to take a lot more energy input to get very small gains. If you could build an engine strong enough, at some point no matter how much faster you spin the engine the velocity will no longer increase without making some other change to increase flow. Hmmmmmm......... Thinking again........... once you reach the speed that you can no longer increase airflow, is that the point where torque has dropped to zero?

[cowpuc]

It is obvious that torque is present all the way to the top RPM reached, It is declining but still present.

 

It is not low pressure that fills the jug it is the higher pressure of the ambient air pushing the charge in that is doing the filling. Artificially aspirated simply increases that filling pressure. The throttle plate simply blocks the high pressure from pushing charge in.

 

As you go past the torque peak, airflow and thus velocity continue to increase all the way to red line where you stop trying to get more. Peak torque happens at peak efficiency. Peak velocity is way higher than peak efficiency. As the velocity keeps getting higher there are diminishing returns where it starts to take a lot more energy input to get very small gains. If you could build an engine strong enough, at some point no matter how much faster you spin the engine the velocity will no longer increase without making some other change to increase flow. Hmmmmmm......... Thinking again........... once you reach the speed that you can no longer increase airflow, is that the point where torque has dropped to zero?

 

Only got a second here but a couple things for Fool to investigate. Jeff, if you have a second, do a quick study on this, at precisely 5252 on an internal combustion engine, do the HP and Torque curves cross and does the HP curve rise above the Torque curve at that given point? If not, without altering the standard graph parameters where torque and hp are shown on by matching stated graph parameters, please show actual dyno graphs dispelling this.

I see you and I have a difference of opinion on #3 above. My input was based on the vacuum pressures altering as the throttle plate angles change. IMHO, this is exactly what makes a CV carb operate effeciently (well,, as effeciently as possible in that it is still a carb), without this given, the vacuum operated slide in a CV carb could not function, at least from my very limited in knowledge opinion.

[Flyinfool]

The thing is, vacuum does not move anything. Do you see stuff flying off the moon because it is surrounded by vacuum? It is the air pressure that is doing the moving. The vacuum simply removes some of the air behind the diaphragm it is the atmospheric pressure that is pushing the diaphragm to make it move.

 

If you take a really thin walled container and pull a vacuum on it the air pressure around it will crush it. If you take that same container into space and suck all the air out of it, nothing will happen. It will just be an empty thin walled container.

 

This is why the engine is not sucking in the air, the engine is simply using torque and HP to create an empty void thru mechanical action, and it is the air pressure pushing the charge in. that is why performance goes down with altitude and the lower air pressure, the piston displacement did not change as you go up in altitude the air pressure to push the charge in has gotten to be less therefor you get less charge and less torque and HP.

 

A turbo or super charger does not increase the vacuum to suck more charge into the cylinder, they simply increase the air pressure that is doing the pushing.

 

The difference seems like just a discussion over semantics, but once you wrap your head around this part it starts to make more sense.

 

One of my favorite test of a theory is to take it to extremes. If the theory still holds true at the very extremes, then it is likely a valid theory. If the theory starts to not work correctly at all extremes then it is not a valid theory just a coincidence for the given set of conditions.

 

I have never done any research into if 5252 is a real thing, or a convenient coincidence or rule of thumb for most cases.

[Flyinfool]

I guess the 5252 is a real thing as long as certain assumptions are made.

 

1. The dyno chart must have the same scaling for both torque and HP. ie if the scale for HP is 0-100 HP, then the scale for torque must also be 0-100 Lb/Ft. If you change either of these the cross will no longer be at 5252. but the torque and horsepower will still be the same number at 5252 just the visual cross will be different.

 

2. The measurements are all done using imperial numbers. Metric will have the curves cross at 9549 rpm. This is strictly due to the different units and their conversions as to the way they will fall visually on a graph. IF you do all of the conversions back to imperial the same engine will again cross at 5252.

 

Here is the best explanation that I have found as to why this happens, It is just math. You will need at least a little understanding of algebra to follow along. He does go thru it a bit fast for some. You may have to back up and watch some segments more than once to keep up.

 

[cowpuc]

I guess the 5252 is a real thing as long as certain assumptions are made.

 

1. The dyno chart must have the same scaling for both torque and HP. ie if the scale for HP is 0-100 HP, then the scale for torque must also be 0-100 Lb/Ft. If you change either of these the cross will no longer be at 5252. but the torque and horsepower will still be the same number at 5252 just the visual cross will be different.

 

2. The measurements are all done using imperial numbers. Metric will have the curves cross at 9549 rpm. This is strictly due to the different units and their conversions as to the way they will fall visually on a graph. IF you do all of the conversions back to imperial the same engine will again cross at 5252.

 

Here is the best explanation that I have found as to why this happens, It is just math. You will need at least a little understanding of algebra to follow along. He does go thru it a bit fast for some. You may have to back up and watch some segments more than once to keep up.

 

 

Excellent find IMHO Jeff. Now to the big question:

Flyinfool:

I can accept the above video as fact:

Yes or No

@Steven G

I can accept the above video as fact:

Yes or No

[cowpuc]

The thing is, vacuum does not move anything. Do you see stuff flying off the moon because it is surrounded by vacuum? It is the air pressure that is doing the moving. The vacuum simply removes some of the air behind the diaphragm it is the atmospheric pressure that is pushing the diaphragm to make it move.

 

If you take a really thin walled container and pull a vacuum on it the air pressure around it will crush it. If you take that same container into space and suck all the air out of it, nothing will happen. It will just be an empty thin walled container.

 

This is why the engine is not sucking in the air, the engine is simply using torque and HP to create an empty void thru mechanical action, and it is the air pressure pushing the charge in. that is why performance goes down with altitude and the lower air pressure, the piston displacement did not change as you go up in altitude the air pressure to push the charge in has gotten to be less therefor you get less charge and less torque and HP.

 

A turbo or super charger does not increase the vacuum to suck more charge into the cylinder, they simply increase the air pressure that is doing the pushing.

 

The difference seems like just a discussion over semantics, but once you wrap your head around this part it starts to make more sense.

 

One of my favorite test of a theory is to take it to extremes. If the theory still holds true at the very extremes, then it is likely a valid theory. If the theory starts to not work correctly at all extremes then it is not a valid theory just a coincidence for the given set of conditions.

 

I have never done any research into if 5252 is a real thing, or a convenient coincidence or rule of thumb for most cases.

 

When a person breathes in air, are the muscles that cause the chest to expand and relax pulling in and pushing out air or is the person not acutally breathing in air thru vacuum and air is being pushed in by atmospheric pressure?

 

Stick with me,, it takes me a while...

[Flyinfool]

When you breath the muscles expand the volume of your chest by pulling the diaphragm down and then the air pressure pushes the air in. Same as a piston moving down increases the volume of the cylinder and then the air pressure fills the volume.

[cowpuc]

When you breath the muscles expand the volume of your chest by pulling the diaphragm down and then the air pressure pushes the air in. Same as a piston moving down increases the volume of the cylinder and then the air pressure fills the volume.

 

When you take a toilet plunger and dump the beer out of it and stick it on your belly and leave it there and it makes a big red hickey looking suck mark on your belly is the red mark from the suction of vacuum being formed by the rubber sides of the plunger or from air pressure inside your body forcing the skin outwardly and making it turn red?

[cowpuc]

Excellent find IMHO Jeff. Now to the big question:

Flyinfool:

I can accept the above video as fact:

Yes or No

@Steven G

I can accept the above video as fact:

Yes or No

 

Setting aside the discussion of whether vacuum is actually real,,, @Flyinfool,, care to answer the above?

[Flyinfool]

Excellent find IMHO Jeff. Now to the big question:

Flyinfool:

I can accept the above video as fact:

Yes or No

@Steven G

I can accept the above video as fact:

Yes or No

 

Yes assuming that Mr Watts estimate of horse power is actually correct. It is generally accepted as the standard to use, but has never been scientifically verified. (At least not that I can find)

 

The 5252 is not due to anything in or even related to the actual engine at all, it is just simple math. That is why you can not design around it.

 

There is a formula for torque and HP, the formula that is accepted as fact stated that torque in lb/ft is equal to HP at 5252 RPM.

[cowpuc]

Yes assuming that Mr Watts estimate of horse power is actually correct. It is generally accepted as the standard to use, but has never been scientifically verified. (At least not that I can find)

 

The 5252 is not due to anything in or even related to the actual engine at all, it is just simple math. That is why you can not design around it.

 

There is a formula for torque and HP, the formula that is accepted as fact stated that torque in lb/ft is equal to HP at 5252 RPM.

 

Tell you what,,, next time you are around a bike shop or two that have a dyno (or a car shop), see if you could get a look at some of their dyno read out sheets and look carefully at the graphs. If the dyno(s) is/are are calibrated and no one has changed the readout numbers so they remain 1:1, each report will show the 5252 cross point where HP takes over and Torque drops under. Another simplier way (and easier study) would be to jump on YouTube and look at a variety of dyno runs.. I have a hunch that what you will see will be an eye opener. Of course,, MANY dyno guys "play" with their dyno's cause big numbers mean big dollars so ya gotta watch out for that BUT,, a lot of those guys who have any reliable history at all are honest enough that they dont play games..

Engine builders and tuners have used this 5252 dynamic as a baseline for many many years. I know the math guy in the vid said he didnt see the importance of what we are talking about BUT - IMHO, he is probably more of a mathman than a real life engine builder/tuner. Fact is, unless your limited in RPM due to piston speed and how volatile things can get when going beyond piston/rod capabilities so you have to tune for torque OR your just wanting to tune for torque cause you like to shift a lot, understanding what is going on there is VERY important. All IMHO, of course..

[Patch]

HaHa you guys are rolling!

Unfortunately I have a project proposal I need to keep my head around for the next day or so...

Haven 't dared read all the posts cause I know it'll distract me. I did read what came in by mail tho.

 

Forgive me if you covered it.. Naturally aspirated limits - volume metric efficiencies what happens after the testing starts (think it thru) and if we are spinning the crank then there has to be torque, but what is working against us that ties these together?

 

We covered it earlier in the thread..

chat soon

[Patch]

Perhaps we have reached the point where a fresh worksheet is in order?

 

Jeff brings to the table his study and principle's that as an engineer guide his thinking so no disputing that fact but the applications of, are what drive enthusiast.

 

The first part that I think may confuse some is vacuum diaphragms, Jeff expresses the other side of the coin. Here you go Puc, there are two pressures at play here; if on one side we lower than atmosphere yet do not increase pressure on the other, the the vacuum pump will move recording to design strength. In a CV it will pull back the piston and metering needle. If we increase pressure on the other side thru flow pressure then it will do the same except it will be quicker to overcome resistance such as from the return spring. Think of it as power assist. But in application and thru a carb there's more to it and is why the pistons bonce.

 

Now if we take two odd numbers and add them we will end up with an even number, that is the rule, we don't question it. If you were helping a young mind and asked, find the eq. common denominated to say 8 and twelve and they answer 4 that would be correct. If you wanted to see if they really understood the question you may ask next, what is the lowest eq, com denominator, after you could add in with fraction so to pop them out of thinking only in even numbers. It really is about understanding math as a tool.

 

If a young fellow asks me to sort thru his busted something, and I ask that he disassemble it first then offered up my wrench/tool did I set him on the right track? Well not if I didn't explain the reason for the ears being a different length or why he may need a long one....

So my point is that we over time take things for granted, forgetting the basics.

 

Bernoulli's and Venturi laws and explained theories are in play even in torque/HP.

 

We know air is a compressible fluid, we know that is has density and viscosity, we also know these are variable so, we use the above two principles to plan around.

My opinion here Jeff Venturi disagrees with some of the connections made to pressures.

 

When we choose plenum we must choose wisely, then we must prove our choice, and we can't do so effectively by bolting it into use before we have completed the math.

 

All angles in a build are critical. All restrictions and interruptions have consequences.

 

Air is the medium we choose to carry our fuel except in direct injection applications. (past blows or injectors)

 

Lets agree that engines are basically air pumps with a combustion cycle.

 

Combustion is the trophy we strive for, so to is it the challenge. Why?

This would be a good time to strike a match and, either use a stop watch or count it off in your head. Striking of the match is ignition as the match begins to burn over time is and that is duration and the remaining problem!

 

Combustion is in fact a chemical reaction, the heat generated expands the gasses in the confined area from the combustion chamber to end of stroke. (same problem)

Time is expressed as duration first in the extraction of the energy from the fuel which requires oxygen, then ignition and time to expand, duration again, hmmm going to need to change angle of ignition then.

Playing with these tables is what performance is all about; regardless of displacement.

Stoichi facts out for us a target based on known efficiencies, lambda measurements are a relatively new tool to us, as a method of measuring where we are or what reality is...

We can choose to alter ratios for different reasons, one guy may say I built to run lean, the other says I running rich because I increased the X do to say a flow limitation?

 

They each face the same problems and will go at their builds based on whats worked for them in the past and what or where their targets are.

 

Jump in anytime guys.. Calling an Arnold;)

[cowpuc]

Excellent find IMHO Jeff. Now to the big question:

Flyinfool:

I can accept the above video as fact:

Yes or No

@Steven G

I can accept the above video as fact:

Yes or No

 

Perhaps we have reached the point where a fresh worksheet is in order?

 

Jeff brings to the table his study and principle's that as an engineer guide his thinking so no disputing that fact but the applications of, are what drive enthusiast.

 

The first part that I think may confuse some is vacuum diaphragms, Jeff expresses the other side of the coin. Here you go Puc, there are two pressures at play here; if on one side we lower than atmosphere yet do not increase pressure on the other, the the vacuum pump will move recording to design strength. In a CV it will pull back the piston and metering needle. If we increase pressure on the other side thru flow pressure then it will do the same except it will be quicker to overcome resistance such as from the return spring. Think of it as power assist. But in application and thru a carb there's more to it and is why the pistons bonce.

 

Now if we take two odd numbers and add them we will end up with an even number, that is the rule, we don't question it. If you were helping a young mind and asked, find the eq. common denominated to say 8 and twelve and they answer 4 that would be correct. If you wanted to see if they really understood the question you may ask next, what is the lowest eq, com denominator, after you could add in with fraction so to pop them out of thinking only in even numbers. It really is about understanding math as a tool.

 

If a young fellow asks me to sort thru his busted something, and I ask that he disassemble it first then offered up my wrench/tool did I set him on the right track? Well not if I didn't explain the reason for the ears being a different length or why he may need a long one....

So my point is that we over time take things for granted, forgetting the basics.

 

Bernoulli's and Venturi laws and explained theories are in play even in torque/HP.

 

We know air is a compressible fluid, we know that is has density and viscosity, we also know these are variable so, we use the above two principles to plan around.

My opinion here Jeff Venturi disagrees with some of the connections made to pressures.

 

When we choose plenum we must choose wisely, then we must prove our choice, and we can't do so effectively by bolting it into use before we have completed the math.

 

All angles in a build are critical. All restrictions and interruptions have consequences.

 

Air is the medium we choose to carry our fuel except in direct injection applications. (past blows or injectors)

 

Lets agree that engines are basically air pumps with a combustion cycle.

 

Combustion is the trophy we strive for, so to is it the challenge. Why?

This would be a good time to strike a match and, either use a stop watch or count it off in your head. Striking of the match is ignition as the match begins to burn over time is and that is duration and the remaining problem!

 

Combustion is in fact a chemical reaction, the heat generated expands the gasses in the confined area from the combustion chamber to end of stroke. (same problem)

Time is expressed as duration first in the extraction of the energy from the fuel which requires oxygen, then ignition and time to expand, duration again, hmmm going to need to change angle of ignition then.

Playing with these tables is what performance is all about; regardless of displacement.

Stoichi facts out for us a target based on known efficiencies, lambda measurements are a relatively new tool to us, as a method of measuring where we are or what reality is...

We can choose to alter ratios for different reasons, one guy may say I built to run lean, the other says I running rich because I increased the X do to say a flow limitation?

 

They each face the same problems and will go at their builds based on whats worked for them in the past and what or where their targets are.

 

Jump in anytime guys.. Calling an Arnold;)

 

Wayyyyy good Patch BUT,, in all that,,, still no answer to the attached question = yes or no? I know Fool did not go by the guide lines set out by The Code and took liberity to explain his "Yes or No" answers to your "Yes or No" questioning but I would appreciate sticking with the guidelines of fairness that the code sets forth, a simple Yes,,, or a No would be fine.

[Patch]

,, well put my friend ...

 

I gotta ask,, are we in agreement that on any and all dyno charts, as applied to all internal combustion engines, that there is an absolute given that the torque curve stays above the horsepower curve until exactly 5250 rpm's and at that point they intersect and then at 5251 rpm's and above that horse power stays above the torque curve?

Wow Puc how about an easy one?

I am assuming that we are talking modified street averages, naturally aspirated and pump gas.

I get why you limit @ 5000ish but to just agree or disagree stunts growth.

If the question is solely based on should the torque curve be above the HP curve? Then yes, but, I am uncomfortable with the limit!

I am not going to comment on catastrophic failures of components because, this usually has more to do with the bottom line more so then possibilities. Then or as described in the vid..

 

So regarding curves, where can we find a 25% equalizer? That’s not gain but equalizer of such curves?

 

Where we divide again: I am going to study my flows; I have to start with air flows and velocities.

 

Now change how we measure these 2 curves and don’t point at the crank output efforts for what the wheels are or aren’t producing and, maybe

So is there an rpm range when admiring the sexy curves of a cam? Hmmm Are there impacts to torque?

The reason that I asked if we could agree on that one fact is that that number (5250) is a baseline for building IMHO. Disagree

That said, your earlier statement that you limit your revves to 6500 rpm is another baseline in building as it gives a parameter to build around and, :Agreed helps choices

if 5250 is where hp becomes the relevant measurement of power and torque becomes a thing of the past at that point, 5252 is a factor on graphs not in my targets

then intake/exhaust flows, carburation, cam options, valve timing all now have a source to build to to obtain effeciency. It is about volume efficiency & duration (s)

Perhaps a short study to determine whether or not the standards of which I have built by thru the years (that 5250 is in fact a hard, unchangeable number) hold any merit BEFORE This is what I have been mindful of my friend! On this issue is, where I think time and distance blurred the line. That said I didn't use Dyno's but I have learned thru them for guidance in choices. I see them as a reference tool. The 2 graphs overlaid are misleading certainly not what Watt was considering 250 years ago?

​

 

OK Puc same dilemma new approach. I wanted to take some time between to think of how I might express this differently, yup I sometimes think slow.

 

Would you agree that in the mentioned graph, torque is still present past 5000 rpm?

Yes or No

 

Would you also agree that in a naturally aspirated engine, low pressure is the fuel delivery system used to transfer the charge or fill the jug?

Yes or No

 

Would you agree that low pressures alter in direct relation to the throttle angle?

Yes or No

 

Would you agree then, that torque peaks seems to correlate to peak velocity?

Yes or No

 

All should be yes even tho I predicked you would say no to it. We can not agree with 3 and disagree at 4 so I fingered I would expose the splinter and just wordsmith the reasons.

Jeff made the mistake of "freeze frame" not that he doesn't know, but that his training reflex kicked in, meaning the piston was not traveling down.

Wayyyyy good Patch BUT,, in all that,,, still no answer to the attached question = yes or no? I know Fool did not go by the guide lines set out by The Code and took liberity to explain his "Yes or No" answers to your "Yes or No" questioning but I would appreciate sticking with the guidelines of fairness that the code sets forth, a simple Yes,,, or a No would be fine.

 

I will tell you all the dark side but not the ratio targets. The true evaluation of torque is based on displacement. The challenge will remain volume metrics, duration and angles.

 

These are just my opinions, not judgments, they are as mentioned based on wins and losses as well as, the good fortune of having shared experience with much smarter guys willing to share than myself, that does not mean they figured it out for me, but rather they set me straight, more than once.

[cowpuc]

 

Here is an interesting explanation of why, in all cases, the hp curve crosses the torque curve at 5252. Given, this guy being a math guru and not an engine builder/tuner clearly see's no reason why that fact would make a difference to anyone but none the less (unless you change the 1 to 1 ratio's on a dyno chart), 5252 is an absolute.

 

 

I guess the 5252 is a real thing as long as certain assumptions are made.

 

1. The dyno chart must have the same scaling for both torque and HP. ie if the scale for HP is 0-100 HP, then the scale for torque must also be 0-100 Lb/Ft. If you change either of these the cross will no longer be at 5252. but the torque and horsepower will still be the same number at 5252 just the visual cross will be different.

 

2. The measurements are all done using imperial numbers. Metric will have the curves cross at 9549 rpm. This is strictly due to the different units and their conversions as to the way they will fall visually on a graph. IF you do all of the conversions back to imperial the same engine will again cross at 5252.

 

Here is the best explanation that I have found as to why this happens, It is just math. You will need at least a little understanding of algebra to follow along. He does go thru it a bit fast for some. You may have to back up and watch some segments more than once to keep up.

 

 

Excellent find IMHO Jeff. Now to the big question:

Flyinfool:

I can accept the above video as fact:

Yes or No

@Steven G

I can accept the above video as fact:

Yes or No

​

 

OK Puc same dilemma new approach. I wanted to take some time between to think of how I might express this differently, yup I sometimes think slow.

 

Would you agree that in the mentioned graph, torque is still present past 5000 rpm?

Yes or No

 

Would you also agree that in a naturally aspirated engine, low pressure is the fuel delivery system used to transfer the charge or fill the jug?

Yes or No

 

Would you agree that low pressures alter in direct relation to the throttle angle?

Yes or No

 

Would you agree then, that torque peaks seems to correlate to peak velocity?

Yes or No

 

All should be yes even tho I predicked you would say no to it. We can not agree with 3 and disagree at 4 so I fingered I would expose the splinter and just wordsmith the reasons.

Jeff made the mistake of "freeze frame" not that he doesn't know, but that his training reflex kicked in, meaning the piston was not traveling down.

 

 

I will tell you all the dark side but not the ratio targets. The true evaluation of torque is based on displacement. The challenge will remain volume metrics, duration and angles.

 

These are just my opinions, not judgments, they are as mentioned based on wins and losses as well as, the good fortune of having shared experience with much smarter guys willing to share than myself, that does not mean they figured it out for me, but rather they set me straight, more than once.

 

A simple YES or NO still awaits on your behalf brother..

[Patch]

 

 

 

 

​

 

 

 

A simple YES or NO still awaits on your behalf brother..

 

 

Really? NO! 5252 is just an overlap of graph. It is just the scale math.