Kevin Johnson

Nope -- I just had the temerity to disagree with you. Shame on me.


Hey guy, you've got a few 928 engines. I don't see you attempting to replicate any of this. Oh yeah -- you measured the oil pump. So did I and my figures were just about dead on with factory specs. Yours were about 25% high.

Man, you've really got some brass ones.

Nope -- I really did intend to measure the diagonal from the start.

Ok, I remade the dam. The initial tests which I posted and where I fully acknowledged that they did not represent perfection gave an angle of 30 degrees. I did the test just now with the extended wall twice and got 34 degrees the first time and 37 degrees the second time, averaging to 35.5 degrees or ~.71 g. In the new 928 book by Long, he cites period wetweather street tires returning .76G (Dunlop) or .81G (Pirelli)


Wow -- you really need to go back over those biased angles I gave -- nowhere near 1G of forward acceleration is required. This is where you actually need to do the lab assignment, Tuomo. I will give you a hint -- the water leaks out heavily at the corner of the sump.


Nope -- I am backing up what I say. Over on the other thread you ask about whether stock B16 Honda rods are piston guided. Yikes. Firstly, you are not thinking too clearly. All the information to answer that was present in the thread and the picture. Second, why don't YOU open up a few hundred engines and start looking at and presenting the technology. BIG TALK on internet forums is cheap.

Correct me if I am wrong -- was I the first person on the Rennlist EVER to notice the deaerator in the early pump and say something about it?

Correct me if I am wrong -- empirical testing shows the product I made for the 928 over four years ago works very well. You're right at didley squat with what you've developed. Like I said, BIG TALK on internet forums is cheap.

Tuomo, with your extraordinary education level, you're the joke in what you're doing here. The sad thing is that some people may take you seriously.

ptuomov

That's on page 75 of the printed version of the book. It says "The Dunlop tyres lacked the wet weather performance and the ultimate level of grip of the Pirellis (0.76g on the skidpan against 0.81g), but their more forgiving sidewall certainly enhanced refinement, especially on rougher patches of road." The "skidpan" is likely a typo and should read "skidpad."

According to "How to Make Your Car Handle" By Fred Puhn, skidpad measures the lateral acceleration and steady-state cornering ability of the car. Not exactly news to most of us, but wanted to give you a source for this claim.

In other words, the above g figures you quoted correspond to lateral acceleration and tilting the pan sideways. Not diagonally. Yet you compare this figure to a diagonal tilt and diagonal g-force, I suspect fully knowing that you are comparing apples and oranges.

...let's review... you were caught with a lie again! You took a lateral g-force measurement and then compared it to your diagonal tilt of the pan! Almost every fact I check in your posts turns out to be made up or misrepresented!

As Frank Williams said about Ferrari being caught spying his team: "Disappointing, but not terribly surprising."

What I say is not going to cause you to lose credibility, because as you correctly point out I am complete nobody. Me being a hobbyist nobody is known to pretty much everyone here. But your problem is bigger than me and my writings. You are losing credibility not because of what I say but because of what you say.

Hilton

Tuomo's posting history is hardly combatative - in fact he goes out of his way to avoid it usually.

Gents - this argument is providing some very good reading and insight into how oiling and the pickup work.. please fight the arguments, not the person, as we'd hate to lose this thread to the abyss!

ptuomov

So you are implying that I am "replicating" your pump measurements? And then you say that I was off by 25% while you were just about "dead on" on with the factory specs?

Let's review.

Who's got the brass ***** again? You were initially off by a factor of ten! And then you have the audacity to complain about my measurement error?! Can't make this stuff up.

Some outsider should quote us the factory spec for the pump capacity at 7000 rpm. Let's see if you hit it with your 2.17 - 21.7 gpm range.

There's also the minor detail that at least the 928 pumps that I've seen are not gerotor pumps, instead they are internal gear pumps. Does there really exist a gerotor (as in GEnerater ROTOR) 928 pump? One wonders if this is also BS.

Kevin Johnson

Yes, you're correct. My tendency to attack is well known. Again, it is the principal reason I did not go into teaching: I did not want to damage young minds. I remember talking to the chair of the department and saying to the effect that it is horrible how one often becomes that which he detests.

Kevin Johnson

Ok, took a quick timeout and have some coffee brewing. Elixir des Lebens.

No, I was attempting to replicate your measurements. Check the timeline. I was very -- extremely -- open with my investigation and calculations and wrote them down as posts here and on speedtalk as I performed them. As I discovered interesting details about the pump I posted them as well.

When there is information that is important to me I try my best to check it out firsthand. It is why the interior of our home is populated by a very large amount of parts for many types of engines. Samantha is very understanding about that. The shop, her garage, a dedicated storage shed and rented storage space are also filled. The county just came after me because our yard has what I will call an excessive number of engine blocks in it. Two more are to be delivered later today. Samantha said that I should call them works of art and how could people object to works of art displayed on the lawn? The other chair in the office here has a Formula Ford block sitting on it. Sigh. I digress too much.


The first thing I did after posting was to do a patent search to see if Porsche was trying to protect the design. It doesn't seem to show up in the US database but Porsche often cites German and other origin patents. I wish I had the time to investigate that further.

A gerotor pump is a member of a subset of the general class of internal gear pumps. I looked at quite a few designs online and even saw where the vertical fin in the pump is an element sometimes used with viscous fluids. If you have one, note the clipped corner of that fin. I need to look into that someday.

Kevin Johnson

Tuomo, here is an experiment I suggest you conduct.

Take an old turntable for records and a small clear plastic rectangular container. Fill the container about 1/4 of the way.

As you move the container to various positions with respect to the center and run the turntable, observe the container from the side.

The surface/edge of the water on the outside wall describes an arc or negative curve. As you shift the container back and forth you can see that there are positions where the bulk of the fluid ends up at the forward end, the rearward end or roughly balanced.

What this means is that the attitude of the car/engine with respect to the (often shifting) focus point of a curve/turn will determine where the majority of the oil flows.

Tilting the pan diagonally gives a rough representation of one possible attitude of the vehicle and flow bias of the oil. How the front and rear suspension is set up is critical even with a car approaching perfect front to rear balance like the 928. Even this experiment does not account for body roll, for example.

No, you were caught assuming a bit too much.

I am very open about the information in my posts. I think what you are demonstrating is a confirmation bias towards anything negative that you can derive/interpret from that information.

You are hardly a complete nobody in any sense of the term and this is why I am holding you to a bit higher standard.

Now, moving on, racers may want to use the highly practical information I just presented. When you go onto the track, hook up a small video camera to record the movement of colored fluid (I suggest water) in a small clear plastic rectangular container that is oriented to be parallel to the engine. When you review the video and correlate it to the turns -- hopefully datalogging as well, you will be able to see a realtime model of how oil is moving in the engine due to lateral acceleration -- minus, of course, the major influence of the rotating assembly. It is one part of a complex situation.

I hope this is helpful to people.

ptuomov

Are you seriously claiming that your diagonal tilt experiment's g-force figures can be honestly compared to the lateral g-force figures from skidpad? They can't. Obfuscate, deny, make up new stuff, obfuscate, deny, make up new stuff.

You are not presenting information, you are presenting disinformation. You comparing the diagonal pan tilt g-forces to skidpad ratings is just one of many examples of disinformation that you have polluted this thread with.

Since it's 2010, instead of doing that one should use DevToaster's Rev (http://www.devtoaster.com/products/rev/) or similar software to record the locations and g-forces. Yes, you can put the i-phone in a sleeve and tape it on the intake manifold. Is your asinine Rube Goldberg machine suggestion intended to sidetrack us in some way and cause us to lose time and energy?

It's not. You making stuff up and posting it here in an authoritative tone does not help people, it hurts people. Hopefully fewer now that you've been exposed as the bull**** artist that you are.

ptuomov

Obfuscation.

A simple question: Did Porsche 928 ever come from the factory with a gerotor oil pump?

Kevin Johnson

Tuomo, a bit earlier in the thread you were citing to me the reason why the gears were increased in height from 21mm to 23mm. In the picture that I have those words in the manual are sitting right next to a picture of a pump body with the gears next to it.

Your homework assignment is to make the effort to look up what a gerotor design can embody. You seemed very happy to explicate the term gerotor.

Best, Kevin

Kevin Johnson

Tuomo, in another thread you are discussing with another member how a simple approximation can be used with respect to integrating the area under a curve.

Your homework assignment is to review that idea you had and then apply the general concept to the above.


Tuomo, in the speedtalk threads on oil pressure in a crossdrilled crank you had difficulty shifting frames of reference in order to see a problem from a different perspective.

Your homework assignment is to work through how tilting the pan in one frame of reference can approximate the angle of repose (or more properly, the surface of repose).


I apologize -- I thought that I made it clear that data acquisition would be wonderful. I looked at the link and the device does not appear to offer the information on vehicle attitude through a turn -- simple lateral and forward acceleration data present an infinite inverse problem of possible solutions for same.

Ah, parsimony. Love it, hate it. Sometimes it is "simply" amazing how much information a "simple" device can convey. Product opportunity, people. Who can package the above in a sleek case and add some electronics for some added value?

Whatever helps you sleep at night, Tuomo.

Best, Kevin

ptuomov

I am sorry that my questions was unclear. Let me rephrase it in the clearest possible terms: Did Porsche 928 ever come from the factory with a gerotor oil pump?

Kevin Johnson

I have uploaded the picture and text. You should be able to tell me the answer to this. This picture looks very similar to the pump I removed from my early engine.

ptuomov

I am surprised that you would want to bring up those threads up here. In case people are interested, here they are:

http://speedtalk.com/forum/viewtopic.php?f=1&t=21630
http://speedtalk.com/forum/viewtopic.php?f=1&t=21471
http://speedtalk.com/forum/viewtopic.php?f=1&t=205

The reason why I am surprised that you'd want to bring those threads up here is that they have lots examples of you making up stuff and of your overall depicable behavior.

Someone who'll read those thread will also see me being wrong about stuff in those threads, but that doesn't particularly bother me because I am often wrong.

ptuomov

I am fairly sure that the pump in the picture is an internal gear pump and not a gerotor pump. I am wondering what pump you've been measuring since you said that you measured a gerotor pump. Makes me wonder if you actually measured a pump or just made it all up.