performance or snake oil?

[leenart]

I'm still not clear what crank scrappers has to do on a vintage site? Why did CTH post it here and not on the Hot Rod section? My main concerns with my car is longivity of parts/componants, keeping the car within a budget and finding parts. Performance and mileage are not high on my list. For me to install this device (and I think this would be about the same for others) is to pull the engine and remove oil pan, and while I am at it might as well replace the lower end as I am already there (standard MB procedure when the lower pan is removed).
My car gets about 100 miles on weekends so long as its not raining. If I break 5k a year thats good. It's vintage, over 40 years old and some of the parts are just no longer available. If the vintage secton applies to cars older then 1980, how many of those cars would benefit from this product? Is 5% increase in horsepower worth it for a MFI car that puts out 115hp? And at what cost? Is the purpose of owning that car its performance? The reason I bought my car was it as an early w111 coupe, it was MFI and it had a documentation of repairs going back to the 1980's. Performance was not even considered. The car looks fantastic going 10mph, 50mph or 80 mph.
So Kevin, even if you convince us of the benefits of your product, that does not mean that we would consider using your product. There is benefits to crank scrappers, but its not something that people on a vintage website would be interested in. At least thats my thought and as for the OP comments about snake oil, well my first thought was, 'who on this site cares' If it was posted on the Hot Rod section I would see some relevancy.
Leonard

[Kevin Johnson]

Leonard, I think I figured out a while back that no matter what I said you are not going to install a scraper. I understand and appreciate your position.

As for the relevancy of the post on a vintage site I can assure you that thousands of owners of all sorts of cars older than 20 years install crank scrapers. Going back at least 40 years it would be a valid period modification but simply one you were not aware of. "Vintage" and "Hot Rod" are not mutually exclusive categories.

I still have an NOS Hermes air foil for my vintage Lotus Europa in its original box. It could be construed as a hot rod part but it is also a period modification. Same thing for wind splits on 60s and 70s BMWs.

I often respond to criticisms of my product wherever they occur. I am sure I inadvertently alienate quite a few potential customers. So be it. I am a fairly odd sort of fellow who just really likes all sorts of engines and thinks about them quite a bit. Always have.

Take care,

Kevin

Originally Posted by leenart

I'm still not clear what crank scrappers has to do on a vintage site? Why did CTH post it here and not on the Hot Rod section? My main concerns with my car is longivity of parts/componants, keeping the car within a budget and finding parts. Performance and mileage are not high on my list. For me to install this device (and I think this would be about the same for others) is to pull the engine and remove oil pan, and while I am at it might as well replace the lower end as I am already there (standard MB procedure when the lower pan is removed).
My car gets about 100 miles on weekends so long as its not raining. If I break 5k a year thats good. It's vintage, over 40 years old and some of the parts are just no longer available. If the vintage secton applies to cars older then 1980, how many of those cars would benefit from this product? Is 5% increase in horsepower worth it for a MFI car that puts out 115hp? And at what cost? Is the purpose of owning that car its performance? The reason I bought my car was it as an early w111 coupe, it was MFI and it had a documentation of repairs going back to the 1980's. Performance was not even considered. The car looks fantastic going 10mph, 50mph or 80 mph.
So Kevin, even if you convince us of the benefits of your product, that does not mean that we would consider using your product. There is benefits to crank scrappers, but its not something that people on a vintage website would be interested in. At least thats my thought and as for the OP comments about snake oil, well my first thought was, 'who on this site cares' If it was posted on the Hot Rod section I would see some relevancy.
Leonard

[leenart]

Kevin
Yes I think you pretty much know my position, but it has been educational for me and I do appreciate your comments. I think your product does have merit. Enough said
Best regards
leonard

[Kevin Johnson]

Originally Posted by leenart

Kevin,
The purpose of design validation is verification of the attributes of that design. Test results from two similiar but slightly different designs are not valid. The test results on a SRT4 engine is not valid in regards to a M100 or M110 engine. They may have been designed and built by the same company but they are not identical. Each engine has its own unique properties and slight variations in design must be accounted for to assure that those variations will not affect the test results and ultimately, the product.
This point is trivial, but it continues to burn engineers who fail to realize that even slight variations can affect designs and test data. I have investigated numerous product failures only to 'reverse engineer' the part and discover that assumptions were made that later proved to be wrong.
Again, this is a vintage section. And your product does make sense, but without test data for each particular engine, the impact of your product is unknown. The test data may indicate that crank scrapers improve the life of an engine, but you can not make a claim that the crank scraper will universally improve all engines.
The statistical data to validate crank scrappers is going to be found in Chevy and Ford engines. Their are more of them, more of them modified and more historical data that will support the use of crank scrappers. Crank scrappers on one engine or testimonials from one or two individuals does not assure that crank scrappers will perform as it should.
The probability of crank scrappers improving engines is positive, but the risk of being wrong is too great given the cost of these engines. Its one thing to use your product on a $500 or $1000 engine when you can support the use of it by sales numbers, testimonials, dyno test, etc. Its another when the engines cost $5000, there is no manufacturer endorsement and testing is unknown.
Leonard

Just an update, Leonard. I have pulled apart a lot more engines in the passing time. I suggest you examine the floor of the M103 -- crank scrapers. Look in the floor of the Porsche 928 -- crank scrapers. Look in the floor of the Porsche 944/968 -- crank scrapers. This use of scrapers was predated by the use of floor mounted scrapers in the Ford FE about 45 years ago.

If you look at my website, I cite a modern GM patent that mentions the style of scraper I use for the 2.3 Mercedes and the respective Porsches -- and incidentally that Chrysler used on the third gen V10 Viper engine. Crank scraper use is considered sound engineering and presumed background knowledge for automotive engineers in engine development.

When you have overwhelming empirical evidence over, what, 50 years from multiple OEMs and the field has moved to the status of prior art in patent citations then you have sound engineering.

The windage control system I designed in 2005 for the Porsche 928 wet sumped engine allowed that engine to survive race conditions of 6800 rpms for the first half of a season and 7200 rpms for the second half. After 43 hours of racing, not including practice, the engine was torn down and no damage to parts was noted. To the best of my knowledge as well as the team's knowledge that had never been accomplished in the prior 35 year history of the engine. That includes multiple efforts by the Porsche factory. The team's previous engine failed in two days at lower rpms (6300) and lower hp output. Multiple racers around the world have had similar results, including Carl Fausett, third place winner in the 2007 Pikes Peak Hill Climb in his supercharged 928.

Edit: I was accused of merely self-promotion when I went on the Rennlist to contribute to a discussion that was rehashing the problems of the 928. To counter that accusation I made the pattern open source and removed references to it on the website. I like engines and improving them. That's what I am about.

The 2006 SCCA National G Production Champion was running one of our windage control scrapers.

Our little company (Samantha and I) now makes more windage control products for more engines for more different marques than any other company in the world. Ever. And they work. I am not sure what you would consider an exemplar of an expert in the field of windage control. Let me know. No, I am not an engineer and do not claim to be one. I studied philosophy and theoretical linguistics.

Still, adding an aftermarket component is done at the owner's risk. Even products that have been tested rigorously can fail unpredictably in use. That's the distribution curve. Porsche recommends discarding perfectly good looking well-engineered and tested Ti connecting rods from the race motors after 40 hours.

I am driving around in a vintage Mercedes 300 SDL. When I get a chance I will make a scraper for it.

Cosworth Engineering recently came out with a competing aftermarket product to offset our offering for the Evo engine.

[cth350]

Now, you've got me wondering. Why did I start this thread?

Kevin, Thx for the update. Now's a great time to plug the product and cost to purchase and install. Seeing as how this thread has been to sleep for two years, it's still nice to have a guest engineer around to talk with.

-CTH

[Kevin Johnson]

Originally Posted by cth350

Now, you've got me wondering. Why did I start this thread?

Kevin, Thx for the update. Now's a great time to plug the product and cost to purchase and install. Seeing as how this thread has been to sleep for two years, it's still nice to have a guest engineer around to talk with.

-CTH

Well, not an engineer. Someone who likes to think about engineering problems. It is hard to explain but I enjoy seeing how the people who designed and built these motors thought and how they solved problems. You can abstract and withdraw their general principles and apply them to other new problems.

I wish that I had more products to offer for the Mercedes line of engines -- the M103 will get one and I believe from that pattern could come one for my own 603, with an adjusted stroke.

A rough estimate of how long they take to install is the RR time for the oil pan. Then add an hour or two to check and if needed adjust clearances with the rotating assembly. I think other questions are addressed on the website.

[Cervan]

i think it would be a good idea on a b18c (GSR) engine spinning at 10k rpms to hit oil at that speed? immagine that for a second. a crank going at ten thousand RPM and hitting oil. it would be like hitting concrete.

[Larry Delor]

I missed this thread 2 years ago. Interesting reading, I'm glad it surfaced again.

Kevin, -Where in Fla. are you located?

[Kevin Johnson]

Originally Posted by Cervan

i think it would be a good idea on a b18c (GSR) engine spinning at 10k rpms to hit oil at that speed? immagine that for a second. a crank going at ten thousand RPM and hitting oil. it would be like hitting concrete.

The spinning crank sets up a pressure differential that actively draws more oil into it as a positive function of rpm. The losses from windage are complex and vary in nature over an rpm range. At high rpms, the rotating assembly would be both moving through entrained oil (friction) and drawing entrained oil along with it (additional mass to accelerate).

If you compare the GSR block to the standard B18B (etc) it has the addition of a girdle and oil injectors. Both increase windage losses.* The extra bracing is needed to stabilize the block at extreme rpms but comes at a cost. Nismo reports that the mere presence of a girdle on the SR20 and KA24E/DE costs about 5% of power output. I am sure there are commensurate losses with the Honda.

*The injectors are vital for cooling, however.

The windage tray for the B18B is also a superior design, but of course it has much fewer constraints on it. Both engines need to fit into the same space alloted in the chassis.

Team Honda Research is running examples of our scrapers and modified windage trays for both the B18C type block and B18B block. They were very helpful in providing fitment feedback.

[Kevin Johnson]

Originally Posted by Larry Delor

I missed this thread 2 years ago. Interesting reading, I'm glad it surfaced again.

Kevin, -Where in Fla. are you located?

Hi Larry,

I am a bit north of Tampa in the New Port Richey area. My Great Aunt lives in the Sarasota area.

Nice twist on Descartes. You have to stop the reflexive inquiry somewhere, though. Else therein lies madness or at least infinite regression.

[Kevin Johnson]

Originally Posted by leenart

I'm still not clear what crank scrappers has to do on a vintage site? ... The reason I bought my car was it as an early w111 coupe, it was MFI and it had a documentation of repairs going back to the 1980's. Performance was not even considered. The car looks fantastic going 10mph, 50mph or 80 mph. ... well my first thought was, 'who on this site cares'

Ich denke an "Karl" in "Drei Kameraden." Der Kompressor pfiff los... u.s.w.

As I cruise at 3000 in an S-class Mercedes factory diesel hotrod an impertenent lesser craft is impeding my steady progress, I want the "Blessed Mother of Acceleration"* to help old Otto out.

*Thank you, Elwood Blues.

[Kevin Johnson]

Update from the SCCA 2007 Runoffs: Our scrapers were used in the: FP National Champion car (Mazda); GP National Champion car (Toyota); 2nd place GP car (and last years GP Champion (VW)).

Snake oil -- I don't think so.

[mercmad6.3]

A lot of the guys who post on here have never seen the inside of their Mercedes Engines, But I have quite often as it happens.So here is the main reason Mr Johnsons idea won't work on our powerplants. They all have drilled conrods which pass oil THROUGH the rod to the gudgeon pins where it both cools the piston and lubes the pin and bore walls. You will soon get most of the engines lube oil sitting on top of the crankshaft, The exact opposite of what his windage tray is trying to alleviate.
Considering the racing and aircraft experience Daimler -Benz had ,and was using in the design of it's engines prior to the 1980's ,I think they forgot more than we will ever know.
His idea is as old as the internal combustion engine itself. My own 1952 Chrysler Hemi V8 had one as stock.

[Kevin Johnson]

Originally Posted by mercmad6.3

A lot of the guys who post on here have never seen the inside of their Mercedes Engines, But I have quite often as it happens.So here is the main reason Mr Johnsons idea won't work on our powerplants. They all have drilled conrods which pass oil THROUGH the rod to the gudgeon pins where it both cools the piston and lubes the pin and bore walls. You will soon get most of the engines lube oil sitting on top of the crankshaft, The exact opposite of what his windage tray is trying to alleviate.
Considering the racing and aircraft experience Daimler -Benz had ,and was using in the design of it's engines prior to the 1980's ,I think they forgot more than we will ever know.
His idea is as old as the internal combustion engine itself. My own 1952 Chrysler Hemi V8 had one as stock.

Unfortunately your reasoning is incorrect and the positive pressure oiling system via drilled rods is, in fact, even more of a reason to run windage trays and scrapers.


There are several areas of misunderstanding.

First, a windage tray in a discrete definition has the technical function of shielding the sump reservoir from the "windage" effects of the air circulating around the rotating assembly and being pumped between or across cylinder bays. The windage tray also helps to shield the rotating assembly from splashing oil in the sump.

It is important to realize that positive pressure oiling to the rods and mains (and gudgeon pins, etc.) is an advance over some pre-war designs that relied upon the rods dipping into the sump reservoir, i.e. splash lubrication. I have a vestige of those pre-war designs sitting in the shop, i.e. an Ingersoll-Rand two-stage air compressor that was originally designed in the 1920s.

You do not have to believe me. Here is a secondary source that confirms what I have written: http://64.78.42.182/sweethaven/MechTech/Automotive01/default.asp?unNum=5&lesNum=3&modNum=13

Splash
The splash system is no longer used in automotive engines. It is widely used in small four-cycle engines for lawn mowers, outboard marine operation, and so on.

In the splash lubricating system (fig. 6-29), oil is splashed up from the oil pan or oil trays in the lower part of the crankcase. The oil is thrown upward as droplets or fine mist and provides adequate lubrication to valve mechanisms, piston pins, cylinder walls, and piston rings.

In the engine, dippers on the connecting-rod bearing caps enter the oil pan with each crankshaft revolution to produce the oil splash. A passage is drilled in each connecting rod from the dipper to the bearing to ensure lubrication.

This system is too uncertain for automotive applications. One reason is that the level of oil in the crankcase will vary greatly the amount of lubrication received by the engine. A high level results in excess lubrication and oil consumption and a slightly low level results in inadequate lubrication and failure of the engine.

Second, windage comprised of both air and entrained oil changes character as rpms rise. A pressure differential is formed in and around the rotating assembly that actively draws oil into it. The ensuing "windage cloud" does not need direct exposure to the neat sump oil to form. The oil ejected from the rods, mains, oil squirters as well as that often draining through the crankcase from the head is more than sufficient to allow the cloud to establish an equilibrium at any given rpm level. The higher the rpm in a normal atmosphere the more oil that is held. If you vary the level of atmosphere you can also vary the entrainment which is one of the reasons dry sumps improve performance, i.e. via depressing the atmosphere in the crankcase.

Third, the presence of excess oil in the upper crankcase -- around the rotating assembly is deleterious to efficient engine operation. It is admittedly counter-intuitive but too much lubricant can sometimes cause failures though heat generation and the subsequent degradation of the oil. Again, you do not have to believe me as here is a secondary source: http://www.uesystems.com/pdf/ms_cbm/Monitoring%20Bearing%20Wear.pdf

Over-Lubrication:
One of the most common causes of bearing failure is over-lubrication. The excess pressure of the lubricant often breaks, or “pops” bearing seals or causes a build-up of heat, which can create stress and deformity.

Fourth, by disrupting the pressure differential in the windage cloud more oil is released more quickly by properly designed scrapers to follow normal radial or tangential ejection paths. This increases the thermal efficiency of the engine by allowing the oil to perform its critical cooling and lubrication functions and then as quickly as possible to remove it and then allow fresh oil to take its place.

Ok, now some more advanced theory. In a depressed atmosphere such as would be seen in a dry sumped racing automotive engine or piston-driven aircraft engine, there is a point where the windage effects decline to such a extent that the spray patterns from the rotating assembly revert to form disks in three-space. Conventional gudgeon pin oiling comes from scraper rings on the piston so as to oil the pin from the outside in. The area of collection of this oil is orthogonal to the disk spray patterns. In other words, the thrust bearing surfaces (and opposite) of the cylinder wall receive disproportionately more oil than the side surfaces of the cylinder near the pins. There are ways to provide lubrication to the pins from the interior of the piston as well as cooling to the piston and the system you noted from Daimler-Benz is one of them.

Yes, the ideas behind the products I make are extremely well supported by empirical evidence spanning at least half a century. It is, however, also extremely important to understand the underlying theory as to why they work.

Now, more precisely to your example: a counter example from a well known firm with excellent engineering that reinforces what I have written previously. Porsche tried cooling/lubricating the underside of the pistons in the wet-sumped 928 V8 via positively directed oil squirters. This modification had to be withdrawn because the additional oil in circulation caused excess heat to be generated as well as aggravating an already fatal air entrainment problem in high rpm use of the engine. Adding multiple scrapers and shielding to the wet-sump 928 V8 both lowers the operating temperature of the oil and allows it to survive the erstwhile fatal air entrainment issues at speed. This has recently been empirically established by racing teams and private owners around the world.

Post comment: I would not quote from Remarque -- "Drei Kameraden" -- about a supercharged car affectionately known as "Karl" in post WWI Germany nor spend time reading de-classified technical papers from the NAACA from about 1917 onwards if I didn't think it was important to appreciate history and what has been tried and why it worked or failed.

[mercmad6.3]

Interesting..I have had a lot of Experience with babbet pounding Ford Model T's,and Chev splash feed sixes so i'm fully aware of how a bearing works ( i'm a Diesel engineer by trade ) ,but I stand by my comments. Imagine if you will that the pistons on most mercedes Engines up to the last of M117 light alloy V8's are oil cooled Plus ,they ALL have the drilled conrods and there are very few production engines which have ever featured this.

One that comes to mind is the XK jag engine.Any one who has ever owned a 3.8 Mk2 will attest to the huge appetite for oil.A direct result of huge amounts of oil splashing around the underside of the pistons and being splashed onto the bore walls. This was necessary for engine longevity ,resulting from a mix of ordinary oil quality and the need for speed from enthusiastic owners.

Now..with the Mercedes engine,I again ask you "where is the oil from under the pistons is expected to run to?" .If there is something in the way of a free flow of oil ,it's going to build up on top of the scaper and flood the crank shaft.Thats Why mercedes engines have such a deep sump pan,which is some distance from the crankshaft centerline. ( EXCEPT THE M-100 6.9 WHICH HAS A SEPERATE OIL TANK,ALA DRY SUMP )
And once again I repeat the statement ." Daimler Benz had vast experience with engines",gained from Racing in the 1930 's and from Aircraft development in the 1930's through to 1945...With that in Mind,don't you think they would have utilised the crank scraper idea?