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Oil Pressure Regulator Questions

zack

Donation Time
My dad's '65 has some oil issues...specifically the oil pressure regulator is junk. He was planning to modify it with the screw but it got a bit damaged during disassembly. After looking at it, I see why it was made the way it was but that reason (low price at high volume) doesn't much matter when making just one.

So, I designed a replacement that I think will be a whole lot better.

I have a few questions that maybe can be answered here.

1.) There seem to be three different oil pressure regulators used. Are these interchangeable? If not, is is just different pressures or are they different sizes?
2.) If I went through the trouble of making blueprints for the improved version, or possibly even offering them for sale, would there be any interest?
3.) Has anyone done any work on this already? I searched for dimensions and materials used in the originals without luck. I can make some assumptions based on construction and I can make measurements of this one but beyond that it's mostly just a clean sheet design based on materials that are appropriate for the task.
4.) Does anyone have the overall length of this (the second of three designs) regulator? I can measure what I think is the right length by sliding the pieces together but it's possible they used a jig when assembling this so I may be off by up to 0.1 inch.
 

Ken Ellis

Donation Time
To question 3, here's some "prior art".

Google up this search string:
site:sunbeamalpine.org OPR adjustable

I believe the R stands for relief (valve), not necessarily regulator. (Not near my books at the moment.)

Making a product for sale would carry with it some responsibility for correct function and graceful failure modes... Not insurmountable, but a factor nonetheless.

I'm sure folks who have looked into things more recently than I will chime in with some of the other details.
 
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hartmandm

Moderator
Diamond Level Sponsor
Do you have a series IV or V?

The screw-on oil filter blocks used two styles of oil pressure relief valves (OPRVs). A thicker steel tube was used before series V and then re-introduced during the series V production run. A thinner brass tube was used for the first part of the series V production run. See attached photos. Which style OPRV do you have?

The different style OPRVs use different oil filter blocks due to the OPRV tube size differences, and different locations for the OPRV threads.

While adding an adjustment screw, I trashed the brass tube on my OPRV. I created a new tube using steel. I have some measurements for the tube - outer diameter and the multiple inner diameters and the depths of each inner diameter. I did not record the overall tube length. I do have a spare brass OPRV that I can measure if needed. However, I don't think being slightly long will matter, because the tube projects into a cavity in the oil filter block. (See attached photo.) I also suspect you are trying to get away from the plunger design, so those measurements might not be relevant.

Mike
 

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Tom H

Platinum Level Sponsor
Zack, I have dealt with this issue for years on my SV. On several occasions I was able to carefully remove the OPR valve while hot and actually see that it was stuck open. A little cleaning and it was always ready to go. UNTIL the next time. It seems to me that all it takes to make the valve stick open is a little bit of grit. This problem occurred several times after I rebuilt my engine. I know I cleaned that block thoroughly, but there must have been some dirty oil in the cooling tube. I tried different filter blocks and OPV and the problem seemed to be still there. I have not had any issues lately during several long distance (2000 mi +) trips, so I assume whatever grit was in my system has gotten removed via oil changes.

Nevertheless I have envisioned a better design. I don't know what you have in mind. but I am 99% sure that the best improvement would be to use a ball instead of a plunger. With a ball design, assuming the ball were slightly smaller than the bore, there is no sliding area where grit can cause sticking. I am pretty sure the physics of a ball design is very similar to that of the plunger, so the spring could be just about the same as original and an adjustable would also be possible

Several years ago some Alpine owner in Europe proposed selling an improved design but I never heard from him after some early follow up. I'll do some searching and see what I can find.

Tom Hayden
 

zack

Donation Time
To question 3, here's some "prior art".
...
Making a product for sale would carry with it some responsibility for correct function and graceful failure modes... Not insurmountable, but a factor nonetheless.

Thanks for the search term. Also, thanks for the warning. I might put up drawings or something but thinking about it I don't think I'd want to sell something that would potentially still be expected to work on cars that will probably not be scrapped ever.


Do you have a series IV or V?

The screw-on oil filter blocks used two styles of oil pressure relief valves (OPRVs). A thicker steel tube was used before series V and then re-introduced during the series V production run. A thinner brass tube was used for the first part of the series V production run. See attached photos. Which style OPRV do you have?

The different style OPRVs use different oil filter blocks due to the OPRV tube size differences, and different locations for the OPRV threads.

While adding an adjustment screw, I trashed the brass tube on my OPRV. I created a new tube using stainless steel. I have some measurements for the tube - outer diameter and the multiple inner diameters and the depths of each inner diameter. I did not record the overall tube length. I do have a spare brass OPRV that I can measure if needed. However, I don't think being slightly long will matter, because the tube projects into a cavity in the oil filter block. (See attached photo.) I also suspect you are trying to get away from the plunger design, so those measurements might not be relevant.

Mike
If series V has brass then it's series V. The pictures are very helpful; that part is still on the car and as with any 50-year-old bolt, removal brings risks. I was planning on using a plunger design but considerably different from what Sunbeam did.

I am 99% sure that the best improvement would be to use a ball instead of a plunger.

Ball designs carry certain issues as well as plunger designs but that is certainly a possibility. Hearing that even a fresh engine can clog one of these with grit does make me think that a ball would be a good idea.

I attached a couple images of the concept I had so far. Still a plunger but a much more rigid one, with chamfered ends to make it less likely to get stuck. This would also keep it from scraping the inside of the tube, something that definitely happened a lot in the original. I think that these scrapes were at least partly to blame for the sticking (the spring was also junk).

I was going to use either 2011 aluminum or 316 stainless for the bolt piece and 932 bearing bronze for the plunger and tube. I think they used either manganese bronze or 954 bronze in the original because it is soldered...manganese is almost as good as 932 for something like this but it doesn't heal itself as well and 954 would be a lot less ideal but it is easy to draw with dies so that would have been attractive to the engineers.

I was also planning on using threads to put it together; soldered assembly on something that contains a spring that will almost certainly wear out just seems like a bad idea on a car that will probably still be on the road after gas stations stop existing.

Thanks to everyone for contributions; I think my design will get some changes because of these ideas.
 

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sunbeam74

Silver Level Sponsor
Opr

I bought one of the pressure relief valves from the Alpine owner in Europe who had new ones made. They were decent.

- Included the threaded adjustment screw
- featured a ball as the shut off versus the plunger

At the time I want to say it was 85.00 but by the time it was shipped here closer to 110.00.

Years ago I had tried to see if I could get his machinist to make a handful more but no luck.


Steve
 

Tom H

Platinum Level Sponsor
Zack, I am curious about what issues arise with use of a ball. I am not a mechanical designer but a pretty good physics guy and it just seems natural that a ball world work better. Maybe it's hard to keep it from weeping / leaking a bit at full temp with low viscosity.

Steve, have you used the ball based one? Does it work well?

Tom
 

zack

Donation Time
Zack, I am curious about what issues arise with use of a ball. I am not a mechanical designer but a pretty good physics guy and it just seems natural that a ball world work better. Maybe it's hard to keep it from weeping / leaking a bit at full temp with low viscosity.

Steve, have you used the ball based one? Does it work well?

Tom

Mainly just additional design concerns, nothing to stop it from being done.

The spring pressing against the top of a ball can cause issues; it won't necessarily sit centered and can rub on the walls. It also has to go past the relief holes, with the ball right after it. This is a potential pinch point but can be dealt with by using 3-5 small chamfered holes instead of 2 large ones. Since the spring is now the same as the cylinder ID you also need to ensure that the spring material isn't harder than the tube material, so bronze is out. This changes the thermal expansion of the OD, but there are materials close to bronze and aparently even using SS doesn't cause issues anyway.

Going to a harder material also causes issues with the inside finish, at least with my equipment. I can get a real nice finish on a small ID with bronze or even some aluminums but not steel; not even 1018.

There is also the issue of oil getting past the ball...this actually isn't too big of a deal because the ball will expand at the same time and at about the same rate that the tube does if materials are chosen with care.

McMaster sells 5/16 balls that look perfect for the job as well as a .313 (that's the tube size it's designed for; it is a bit smaller than that) spring that would serve well. Based on those my current idea is to have three 3/16 round holes instead of the two 1/4 square holes in the original (this would create the same total area for oil to flow out). I think these should be stepped up the shaft, so that they start to release oil one at a time.

I'm tempted to use 2011 aluminum for the whole thing...I can get a nice inside bore finish with that and it meets all the requirements listed so far. It has a nice low thermal expansion coefficient too.

If this works I'll post diagrams and DWG's that could be brought to virtually any machine shop so no one is relying on one machine shop that made some years ago and might not even exist anymore.
 

zack

Donation Time
Redesigned to have a ball. There is also an adjustment screw. By my math it should begin to open at about 30.0PSI and go full open at about 43.7PSI when in the "minimum" setting...the screw would increase those numbers...in fact if you screwed it in all the way it would just be a block-off. Thoughts?
 

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65beam

Donation Time
Questions

There is some good info concerning Alpine oil pressure related problems on the Tigers East/Alpines East site. Check out tech tips # C2, C15 and C40. C15 is very informative.
 

RootesRacer

Donation Time
Not saying the ball wont work, but compared to the barrel style, the mechanical gain once the ball hits the dump port will be MUCH higher (than the barrel type).

The OPR will have a much narrower stroke range in regulation, will regulate at the low end of pressure control range and very likely will oscillate in operation which will probably wear the unit (not the ball) out quickly.

If you are going to use a ball, you should consider a different dump port strategy (small and progressive) so that the mechanical gain of the valve is similar.
 

Tom H

Platinum Level Sponsor
Rootes, I'm trying to understand the "mechanical gain" concept here and I think I get it. Note that Matt did say the dump ports would be "stepped". Maybe progressive in size as well is better yet. At full relief, with either ball or barrel type, the restriction is simply the size of the holes. At no relief both designs allow no dump. I can imagine that the curve from one extreme to the other could / would be different. Couple questions:
1) In normal operation at operating temp, is the OPR actually adjusting system pressure or is it in fully closed position and the oil pump is doing the best it can to maintain 40 PSI or so? Note that the device is called a OP RELIEF valve and not a regulator.

2) with a ball design, can it be a slightly looser fit, with reduced likelihood of sticking? Or would that cause oscillation right near the closed end? In other words, does a ball design require a "seal" against the wall in addition to the seal on the end?

Initially this all seemed pretty simple to me, but obviously it's more complex.

Tom
 

RootesRacer

Donation Time
Rootes, I'm trying to understand the "mechanical gain" concept here and I think I get it. Note that Matt did say the dump ports would be "stepped". Maybe progressive in size as well is better yet. At full relief, with either ball or barrel type, the restriction is simply the size of the holes. At no relief both designs allow no dump. I can imagine that the curve from one extreme to the other could / would be different. Couple questions:
1) In normal operation at operating temp, is the OPR actually adjusting system pressure or is it in fully closed position and the oil pump is doing the best it can to maintain 40 PSI or so? Note that the device is called a OP RELIEF valve and not a regulator.

2) with a ball design, can it be a slightly looser fit, with reduced likelihood of sticking? Or would that cause oscillation right near the closed end? In other words, does a ball design require a "seal" against the wall in addition to the seal on the end?

Initially this all seemed pretty simple to me, but obviously it's more complex.

Tom

Tom, You're an electrical guy, think high electrical gain in a closed loop system, its a good analogue anyhow.
An oil pressure regulator acts like a Proportional ONLY controller in electronics terms. It attempts to control pressure but we must accept the typical errors associated with Proportional only control where variation in in the behavior of the system would necessitate a change of proportional gain in order to have both accuracy and stability.
The mechanical OPR is a closed loop system as its motion causes control through negative feedback just like any closed loop electronic control.
Just like electronic feedback systems there is a phase shift in feedback which is accounted for in the design. The phase shift in the mechanical case is the mass of the barrel/control element and the spring that drives it. Air in the oil probably also effects the phase shift but that is probable not a dominant pole due to the resonance difference.

The barrel system has a somewhat linear gain function where the barrel begins to flow a very small amount as the barrel uncovers a sliver of dump port. The dump flow becomes somewhat linear as a function of the area uncovered by the barrels position. The engineers that designed it considered the oils viscosity properties and came up with a compromise between new/old/hot/cold oils and the RPM band it was to operate over.
They sized the dump port, the dump begin and end positions based on this compromise.

The ball valve however will act quite a bit differently when used with the same dump port. The begin dump pressure will be the same as the barrel valve as its the oil pressure that moves the ball to the same position as the barrel at the begging of the port dump position. This is where the similarity ends.
An increase in pressure will cause case an increase in the balls opening position but since there is a radial clearance transition instead of a 90 degree block, the small about of position change will cause a large change in flow. With a sufficiently large dump orifice pair, the dump flow as a function of dump position will be exponential instead of linear. This would cause resonant and stability problems as the OPR tries to attain its control point.
If you consider that there will be normal pressure perturbations due to the oil pump having rotational pressure variations, consider that the OPR will need to vary its position in response. If the control position variation is nor similar in displacement for a given pressure perturbation, your can be sure you are operating outside the parameters that the original OPR was designed (dump orifices, positions, mass and spring rate).

I would imagine an iterated process of building with smaller orifices drilled to cause a progressive increase in dump flow across a similar dump position range as the original will produce a similar mechanical gain envelope and thus a stable control system.
I say iterated becuase one would need to know a lot about the properties of oil to be able to model it.
Outside my pay grade anyhow.
 
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zack

Donation Time
Tom, You're an electrical guy, think high electrical gain in a closed loop system, its a good analogue anyhow.
An oil pressure regulator acts like a Proportional ONLY controller in electronics terms. It attempts to control pressure but we must accept the typical errors associated with Proportional only control where variation in in the behavior of the system would necessitate a change of proportional gain in order to have both accuracy and stability.
The mechanical OPR is a closed loop system as its motion causes control through negative feedback just like any closed loop electronic control.
Just like electronic feedback systems there is a phase shift in feedback which is accounted for in the design. The phase shift in the mechanical case is the mass of the barrel/control element and the spring that drives it. Air in the oil probably also effects the phase shift but that is probable not a dominant pole due to the resonance difference.

The barrel system has a somewhat linear gain function where the barrel begins to flow a very small amount as the barrel uncovers a sliver of dump port. The dump flow becomes somewhat linear as a function of the area uncovered by the barrels position. The engineers that designed it considered the oils viscosity properties and came up with a compromise between new/old/hot/cold oils and the RPM band it was to operate over.
They sized the dump port, the dump begin and end positions based on this compromise.

The ball valve however will act quite a bit differently when used with the same dump port. The begin dump pressure will be the same as the barrel valve as its the oil pressure that moves the ball to the same position as the barrel at the begging of the port dump position. This is where the similarity ends.
An increase in pressure will cause case an increase in the balls opening position but since there is a radial clearance transition instead of a 90 degree block, the small about of position change will cause a large change in flow. With a sufficiently large dump orifice pair, the dump flow as a function of dump position will be exponential instead of linear. This would cause resonant and stability problems as the OPR tries to attain its control point.
If you consider that there will be normal pressure perturbations due to the oil pump having rotational pressure variations, consider that the OPR will need to vary its position in response. If the control position variation is nor similar in displacement for a given pressure perturbation, your can be sure you are operating outside the parameters that the original OPR was designed (dump orifices, positions, mass and spring rate).

I would imagine an iterated process of building with smaller orifices drilled to cause a progressive increase in dump flow across a similar dump position range as the original will produce a similar mechanical gain envelope and thus a stable control system.
I say iterated becuase one would need to know a lot about the properties of oil to be able to model it.
Outside my pay grade anyhow.

You are right that as a ball-based unit opens it releases more oil for a given distance of travel, and that is doesn't do it on a flat curve like you get with a piston and a square opening. That's part of the reason why the unit I designed has a spring that is only half as long as the one in the stock regulator.

That said, the difference this causes in movement is not one of frequency...the ball moves up and down at the same frequency given the same engine/oil pump/etc. The difference is in the distance and velocity of the movement...the ball doesn't move as far or as fast. The ball also has less surface resistance, so this could allow for a faster frequency but if the concern is that a higher frequency would cause more wear then these cancel each other out.

If the concern is that the ball design would cause oil pressure to go too low, that isn't an issue either because the ball is preloaded and wouldn't allow any oil past below the set minimum anyway. Anything more than the set minimum would just be extra bearing wear and shorter seal life so a quicker release is actually a good thing.

The main issue I've had (other than the limitations of my equipment and tooling) is finding a spring that is right in all the ways I need it to be. In fact, the current design is built around the spring instead of the spring being chosen for the design.

I tried making the unit today but I made the mistake of saving the threading for last...the material was so thin at that point that cutting the threads caused enough axial load to bend the tube. I have no more stock of the right size and type so I guess I'm done trying until the metal store opens on monday.
 
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RootesRacer

Donation Time
That said, the difference this causes in movement is not one of frequency...the ball moves up and down at the same frequency given the same engine/oil pump/etc. The difference is in the distance and velocity of the movement...the ball doesn't move as far or as fast. The ball also has less surface resistance, so this could allow for a faster frequency but if the concern is that a higher frequency would cause more wear then these cancel each other out.

First of all, don't take this offensively, I tend to come across very abrasively in written form...

That you wrote the above without concern for the new resonant frequency suggests that you do not understand the actual physics that will occur.

You agree that the ball will pass more oil with less displacement, this is good.
It absolutely will.

If we say that the flow/displacement ratio increases by say a factor of 4, the regulator will then have 1/4 the damping factor at the same stimulus frequency. If we assume the original designer know his $hit and the regulator had adequate damping to prevent oscillation when the oil was at its thinest, this means that the new regulator (ball piston and same dump orifices) now it 4 times more likley to break into oscillation.

What would this mean?
As far as a regulator goes, it will regulate, it will even regulate at the lower end of the design which I think you said should be about 30psig. Since it has a greater mechanical gain due to the ball piston, it will not get to as high of regulation pressure when the oil is cold as compared to the barrel design as there will be a lesser proportional error (on the ball design) due to its elevated mechanical gain.
The added mechanical gain means that the lesser control loop damping will likley cause the regulator to break into oscillation (resonance between the spring and the ball mass).

The oil pressure gauge may or may not register the pressure oscillations, that depends on how much air is in the oil pressure line and how the OP gauge' frequency response.
If the unit oscillates, the ball will wear into the cylinder that it runs in (in the same way that years of operation wears the step in the stock OPR that eventually causes the OPR to stick open with zero OP. That ball will be very hard as compared to the soft steel OPR body. I would expect that the resultant wear will cause a gradual drop in OP due to excessive ball to body clearances.

Now dont get me wrong, I think there is a lot of potential with this ball piston scheme, I think thought that going with a stock OPR body and/or with the stock dump orifice size and configuration will result in the problems above.

A simple and effective solution would be to make a new body, calculate the base dump port location based on spring pressure and piston area, then drill small orifices radially and at progressively farther distances.
Install and run tests to make sure you have a progressive oil pressure as a function of RPM (stock OPRs usually regulate 35psig at warm idle and 45 or 50psig at 3000rpm). This is the characteristic you want to emulate.
Enlarge the orifices and tune the progression till it acts like stock.
You also want to test hot and dead cold oil to make sure it stays stable and accurate under all reasonable conditions. This is likely what the factory did when they designed the original.
 

Tom H

Platinum Level Sponsor
Jarrid, you speak about the device "regulating" the OP. This implies that under normal operating temp and conditions that the device is actually in play, adjusting, controlling the OP. But I note it is called an OP relief valve. This implies to me that it only comes into play before normal operating temp is reached simply to relieve the abnormal high pressure that occurs before operating temp. How likely is it that during normal operating temp, the oil pressure is below the relief limit and the valve stays closed most of the time?

Tom
 

RootesRacer

Donation Time
Jarrid, you speak about the device "regulating" the OP. This implies that under normal operating temp and conditions that the device is actually in play, adjusting, controlling the OP. But I note it is called an OP relief valve. This implies to me that it only comes into play before normal operating temp is reached simply to relieve the abnormal high pressure that occurs before operating temp. How likely is it that during normal operating temp, the oil pressure is below the relief limit and the valve stays closed most of the time?

Tom

No, it may be called a relief valve but like all OPRs, it's a regulator.
When they stick shut, they blow up the oil filter. When they stick open, you get zero oil pressure (or darn near it).

It relieves pressure in that when above the pressure control point, the pressure is "relieved" and drops below the control point back to the sump.

The only time the OPR is closed is when the pressure is below 30psig which can occur under hot idle (or when the engine is not running). Rev the engine up a bit and the valve will dither about its pressure control point somewhere between fully closed and fully open.
It is regulating 100% of the time that the pressure is between 30 and 45psig, hence the control systems dissertation.
 

zack

Donation Time
First of all, don't take this offensively, I tend to come across very abrasively in written form...

That you wrote the above without concern for the new resonant frequency suggests that you do not understand the actual physics that will occur.

You agree that the ball will pass more oil with less displacement, this is good.
It absolutely will.

If we say that the flow/displacement ratio increases by say a factor of 4, the regulator will then have 1/4 the damping factor at the same stimulus frequency. If we assume the original designer know his $hit and the regulator had adequate damping to prevent oscillation when the oil was at its thinest, this means that the new regulator (ball piston and same dump orifices) now it 4 times more likley to break into oscillation.

What would this mean?
As far as a regulator goes, it will regulate, it will even regulate at the lower end of the design which I think you said should be about 30psig. Since it has a greater mechanical gain due to the ball piston, it will not get to as high of regulation pressure when the oil is cold as compared to the barrel design as there will be a lesser proportional error (on the ball design) due to its elevated mechanical gain.
The added mechanical gain means that the lesser control loop damping will likley cause the regulator to break into oscillation (resonance between the spring and the ball mass).

The oil pressure gauge may or may not register the pressure oscillations, that depends on how much air is in the oil pressure line and how the OP gauge' frequency response.
If the unit oscillates, the ball will wear into the cylinder that it runs in (in the same way that years of operation wears the step in the stock OPR that eventually causes the OPR to stick open with zero OP. That ball will be very hard as compared to the soft steel OPR body. I would expect that the resultant wear will cause a gradual drop in OP due to excessive ball to body clearances.

Now dont get me wrong, I think there is a lot of potential with this ball piston scheme, I think thought that going with a stock OPR body and/or with the stock dump orifice size and configuration will result in the problems above.

A simple and effective solution would be to make a new body, calculate the base dump port location based on spring pressure and piston area, then drill small orifices radially and at progressively farther distances.
Install and run tests to make sure you have a progressive oil pressure as a function of RPM (stock OPRs usually regulate 35psig at warm idle and 45 or 50psig at 3000rpm). This is the characteristic you want to emulate.
Enlarge the orifices and tune the progression till it acts like stock.
You also want to test hot and dead cold oil to make sure it stays stable and accurate under all reasonable conditions. This is likely what the factory did when they designed the original.

No offense taken; I have the tendency to offend as well so please return the courtesy on that front.

One thing you are assuming here is that the original designer really knew his stuff and went to extremes to get everything right. I would say that this is a bad assumption just based on the fact that the thing is such a problem area. If you want to talk about bad engineering in a specific and first-year community college kind of way, the dump ports are square without radiused corners. The typical engineering school will teach this lesson over and over again starting in the first semester, while the physics you are talking about are at least semester 4...and the next regulator fixed this so it was likely an issue. I really don't think the guy that design this knew his stuff, or if he did, he was cutting corners.

You are right that a hard ball would cause wear into the ID of the cylinder. Unfortunately there is a balancing act going on because if the ball is too soft then the spring scratches it and the ball transfers those scratches to the inside of the cylinder causing even more wear. We have complete control over the cylinder material (within the limits of what can be machined at that size anyway). We have some control over the ball material; I'm pretty sure you can get aluminum balls in most every size and you can certainly get 304 (relatively soft by SS standards). The spring material we are sort of stuck with unless we want to spend $500 on a custom run of 50 springs. That means that the perfect design would have a ball harder than the spring and a tube the same hardness as the ball...possible with the right tooling, heat treating equipment, and rockwell tester, not possible with my setup. I'd like to make this myself but if push comes to shove I could job it out.

I've only had physics 1 and statics so far. My understanding of resonant frequencies is that 1.) You almost have to try to get something that is actually destructive. 2.) In a system where forces are applied like this, the only way to change the resonant frequency is to change one of the forces (the oil pressure variation on one end, the spring on the other). Based on these I'd think that increasing the travel would not increase the dampening, and since the flow rate and oil pumps remain the same the only real change from stock to the ball design is the spring used. Maybe when I take physics 2 I'll learn that one or both of these is only correct in basic calculations.

One other thing maybe you could explain...as far as the oil is concerned, a restriction is a restriction. A round, flat, or convex faced restriction will all be the same. When a ball moves to a point about 0.0001" past the radius it begins to release some tiny bit of oil. The same is true for a piston that has moved 0.0001" past it's face. At 0.01", 0.1", or 0.25" past the radius, wouldn't the oil released be the same (given the same release ports, spring, etc) as a piston that has moved 0.01", 0.1" or 0.25" past the face? If anything I'd think the other half of the ball being in the path of the oil would actually reduce the amount released a tiny bit by reducing the flow?

You say that designing this correctly would require iterative testing. You say this is because of the resonant frequency. The problem there is that you really can't...not without making the thing out of glass, putting it in a glass oil filter housing, mounting the whole engine on a stand, and using cameras or lasers to measure the frequency. Any equipment that would do it by pressure or vibration would be overwhelmed by the vibration of the whole engine or the pressure variances of the oil pump. You also wouldn't see it in the gauge because it would be faster than the stock variances and the gauge is designed with dampening to prevent it from showing those.
 
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