Reciprocating weight tests ?

[SchmidtMotorWorks]

This is interesting. But I don’t believe it wins races as presented.

What "it" do you mean?

[SchmidtMotorWorks]

what is the consequence on the power measured when you lower MMOI on a chassis dyno that uses a controlled acceleration rate?

It changes the measurement.
What is the value of that data?

[Stan Weiss]

Math to detirmine effects of adding rocker nose weight?

viewtopic.php?t=33578&sid=ec07bc52c1d4d ... 8d69b94113

Stan

[digger]

what is the consequence on the power measured when you lower MMOI on a chassis dyno that uses a controlled acceleration rate?

It changes the measurement.
What is the value of that data?

that is not the question, you claimed the following

I'm curious, who believes that DVs claim that reducing mass increases rear wheel power?
Hint; The work being done was reduced, the power was not increased.

What is happening at least on the dynos around here with constant acceleration rate is when MMOI is redcued the engine is producing the same power but the dyno reads higher hp at the wheels as less goes into accelerating the mass

[dynoflo]

i have built many 2 barrell 350 circle track motors and the ones with light cranks rod and pistons always accelerate quicker. On my dyno they make about the same tq and hp. On the race track its a different story. Im not going to have a pis---- match about it.

[juuhanaa]

what is the consequence on the power measured when you lower MMOI on a chassis dyno that uses a controlled acceleration rate?

It changes the measurement.
What is the value of that data?

that is not the question, you claimed the following

I'm curious, who believes that DVs claim that reducing mass increases rear wheel power?
Hint; The work being done was reduced, the power was not increased.

What is happening at least on the dynos around here with constant acceleration rate is when MMOI is redcued the engine is producing the same power but the dyno reads higher hp at the wheels as less goes into accelerating the mass

Forget light weight for a moment. We just cant make all the parts a feather light to make best wheel hp, because that would be stupidity! BTDT.

Hint hint; engine performance vs vehicle performance. It doesn't need to be that light to make hp, because when the engine makes the most torque at the highest rpm, thats when it has a good chance to accelerate the car as well.




-juhana

[digger]

It changes the measurement.
What is the value of that data?

that is not the question, you claimed the following

I'm curious, who believes that DVs claim that reducing mass increases rear wheel power?
Hint; The work being done was reduced, the power was not increased.

What is happening at least on the dynos around here with constant acceleration rate is when MMOI is redcued the engine is producing the same power but the dyno reads higher hp at the wheels as less goes into accelerating the mass

Forget light weight for a moment. We just cant make all the parts a feather light to make best wheel hp, because that would be stupidity! BTDT.

Hint hint; engine performance vs vehicle performance. It doesn't need to be that light to make hp, because when the engine makes the most torque at the highest rpm, thats when it has a good chance to accelerate the car as well.

-juhana

The discussion hasn’t been about whether you should make parts feather weight or not.

In any case at top level Motorsport they always aim make things lighter to the point it doesn’t cause issues with reliability, durability, parasitic loss etc . They certainly are not deliberately making things heavy except where that solves the above issues.

Ultimately vehicle performance matters except on a dyno competition and the mass that matters is the vehicle equivalent mass which is “translational mass” and “rotational mass”

[juuhanaa]

that is not the question, you claimed the following



What is happening at least on the dynos around here with constant acceleration rate is when MMOI is redcued the engine is producing the same power but the dyno reads higher hp at the wheels as less goes into accelerating the mass

Forget light weight for a moment. We just cant make all the parts a feather light to make best wheel hp, because that would be stupidity! BTDT.

Hint hint; engine performance vs vehicle performance. It doesn't need to be that light to make hp, because when the engine makes the most torque at the highest rpm, thats when it has a good chance to accelerate the car as well.

-juhana

The discussion hasn’t been about whether you should make parts feather weight or not.

In any case at top level Motorsport they always aim make things lighter to the point it doesn’t cause issues with reliability, durability, parasitic loss etc . They certainly are not deliberately making things heavy except where that solves the above issues.

Ultimately vehicle performance matters except on a dyno competition and the mass that matters is the vehicle equivalent mass which is “translational mass” and “rotational mass”

Id rather take a big cam lobe than a small one. Its not the lightest, but i have one from catcams. It controls the valve events pretty accurately via the hydraulic lifter and I rev the engine as high as i can.

Want other example how to make wheel hp?



-juhana

[Geoff2]

Of course making the cam smaller can be counter-productive. Silly example. The idea is to reduce weight that [a] benefits acceleration but does not hurt reliability or power making ability. Small cams can twist/flex.

[digger]

Forget light weight for a moment. We just cant make all the parts a feather light to make best wheel hp, because that would be stupidity! BTDT.

Hint hint; engine performance vs vehicle performance. It doesn't need to be that light to make hp, because when the engine makes the most torque at the highest rpm, thats when it has a good chance to accelerate the car as well.

-juhana

The discussion hasn’t been about whether you should make parts feather weight or not.

In any case at top level Motorsport they always aim make things lighter to the point it doesn’t cause issues with reliability, durability, parasitic loss etc . They certainly are not deliberately making things heavy except where that solves the above issues.

Ultimately vehicle performance matters except on a dyno competition and the mass that matters is the vehicle equivalent mass which is “translational mass” and “rotational mass”

Id rather take a big cam lobe than a small one. Its not the lightest, but i have one from catcams. It controls the valve events pretty accurately via the hydraulic lifter and I rev the engine as high as i can.

Want other example how to make wheel hp?



-juhana

I said lighter not smaller. It’s pretty obvious what I mean. On the topic of camshafts hollow is one way even though it may end up physically bigger there are mass savings

[juuhanaa]

The discussion hasn’t been about whether you should make parts feather weight or not.

In any case at top level Motorsport they always aim make things lighter to the point it doesn’t cause issues with reliability, durability, parasitic loss etc . They certainly are not deliberately making things heavy except where that solves the above issues.

Ultimately vehicle performance matters except on a dyno competition and the mass that matters is the vehicle equivalent mass which is “translational mass” and “rotational mass”

Id rather take a big cam lobe than a small one. Its not the lightest, but i have one from catcams. It controls the valve events pretty accurately via the hydraulic lifter and I rev the engine as high as i can.

Want other example how to make wheel hp?



-juhana

I said lighter not smaller. It’s pretty obvious what I mean. On the topic of camshafts hollow is one way even though it may end up physically bigger there are mass savings

Weight the cam and have fun experimenting. Just saying a balanced person dares to stagger, and modify ports bigger.. does it become lighter that way or not is something to think about



-juhana

[BCjohnny]

i have built many 2 barrell 350 circle track motors and the ones with light cranks rod and pistons always accelerate quicker

I've never come a cross an instance where sensibly reducing MOI inside an engine, that has to accelerate then decelerate during a race, doesn't allow some improvement, never

OK with a drag car heavy flywheel 'stored energy' is a different case, but I don't do drag stuff, and you still have to accelerate the engine MOI down the rest of the strip after you've launched it

While it's useful to chuck all the maths around, simplistically a wind up toy analogy illustrates the basics involved ....... slow to wind up, slow to slow down

It's this latter effect that I think is underestimated, most seem to just focus on the ability to accelerate all of this coming out of the corner but you have a bigger 'problem' slowing it all down again at the end of the straight at tracks where you have to slow for the corners ....... it's spinning much, much faster and you have far less time to dissipate the stored energy

[Stan Weiss]

Forget light weight for a moment. We just cant make all the parts a feather light to make best wheel hp, because that would be stupidity! BTDT.

Hint hint; engine performance vs vehicle performance. It doesn't need to be that light to make hp, because when the engine makes the most torque at the highest rpm, thats when it has a good chance to accelerate the car as well.

-juhana

The discussion hasn’t been about whether you should make parts feather weight or not.

In any case at top level Motorsport they always aim make things lighter to the point it doesn’t cause issues with reliability, durability, parasitic loss etc . They certainly are not deliberately making things heavy except where that solves the above issues.

Ultimately vehicle performance matters except on a dyno competition and the mass that matters is the vehicle equivalent mass which is “translational mass” and “rotational mass”

Id rather take a big cam lobe than a small one. Its not the lightest, but i have one from catcams. It controls the valve events pretty accurately via the hydraulic lifter and I rev the engine as high as i can.

Want other example how to make wheel hp?



-juhana

I don't know what engine / cam you have, but with an in block cam the more lobe lift it has the smaller the base circle has to be.

Stan

[juuhanaa]

The discussion hasn’t been about whether you should make parts feather weight or not.

In any case at top level Motorsport they always aim make things lighter to the point it doesn’t cause issues with reliability, durability, parasitic loss etc . They certainly are not deliberately making things heavy except where that solves the above issues.

Ultimately vehicle performance matters except on a dyno competition and the mass that matters is the vehicle equivalent mass which is “translational mass” and “rotational mass”

Id rather take a big cam lobe than a small one. Its not the lightest, but i have one from catcams. It controls the valve events pretty accurately via the hydraulic lifter and I rev the engine as high as i can.

Want other example how to make wheel hp?



-juhana

I don't know what engine / cam you have, but with an in block cam the more lobe lift it has the smaller the base circle has to be.

Stan

Well in the old Fiat twincam, a 12mm lift is about all that can fit inside the housings. A smaller base circle cam can be fun to brag about but its something for a tow engine with a limited revs.



-juhana

[In-Tech]

The lobe can't be larger than the housing bore. The only way to increase valve lift is to take it off the base circle and then correct the geometry.