When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
It had the spring in the bottom, but that's to make sure the cartridge is pressed firmly against the gasket at the top. Now that I think about it, that probably operates the silicone anti-drainback valve when the engine is turned off. Since the oil is free to surround the cartridge inside the filter, there's no pressure differential between the cartridge's top and bottom in case of blockage. I did not find the perforated spring-loaded assembly at the front, but just a collar without holes/springs whatever. This pic shows it, part in red was not found on my filter: https://imgur.com/a/T7xvpP7. Was it on yours?
Charles, would you be able to comment on the extreme cold considerations in terms of protection against oil starvation during startup in such conditions? From your earlier comment you seem to agree that - while the Napa definitely flows plenty under normal conditions - the OEM Porsche filter has a much high flow capacity due to its size:
Originally Posted by Charles Navarro
The Napa 1042 filter I chose to use on the spin on filter adapter is from a 97-04 Chevrolet Corvette and sized plenty big for the M96 engine. The stock Porsche filter was sized for 24,000 mi drain intervals originally. The 1042 we recommend 5k intervals, which is still less then GM's recommended interval on that filter.
Any thoughts on how you think that affects tolerance to extreme cold?
This whole idea that spin on oil filter is something beneficial really stumps me. I was thinking it might be a good idea but I'm just not seeing any advantage so what am I missing.
Oil changes might be a minute or two faster but checking the filter element is going to be quite a bit longer so no real benefit to a spin on can versus a cartridge filter.
Does a spin on oil filter adapter and a filter without bypass but a higher flow rate that Porsche originally intended help? Wouldn't Porsche specify a filter that meets the engine's needs? Have any of our engines been starved for oil using a Porsche recommended filter?
Does anyone have any evidence of the bypass opening with 0W-40 at cold temperatures?
Does it even matter if the bypass does open? Keep in mind that if it did, it's still passing oil that was filtered when you were last running your engine so is there any real risk?
The main problem with the stock filter setup is that the bypass-valve is located in the bottom of the canister. When debris collects in the oil filter (= the only place where debris collects), it may sink to the bottom when the engine is turned off and collect right in front of the bypass-valve. If the valve then opens, the debris may be sucked into the engine.
Does anyone have any evidence of the bypass opening with 0W-40 at cold temperatures?
This is something I'd like to see as well, as it's being hammered on time and again as a major selling point for the spin-on, as "the bypass opens frequently on cold starts" (IMO only with a faulty valve). I have no doubt that the by-pass opens at cold temperatures, but only in extreme abnormal cold. But the key point I want to drive home is that if the bypass would open due to cold oil, you'd always be better off with a bigger filter if you delete the bypass. So modding the stock would be better than spending 200$ for an adapter and smaller filter.
Murph,
I thought the 0W-40 would stay at about a 0 weight down to well be 0C. Here's a chart I found of 10W-30. It shows that it stays at 10 weight down to -20C. If it can flow to every part of your engine that it needs to get to, why would it blow off the bypass at the filter?
Dave
You have to take the "multi-viscosity" thing out of the equation, but it's not as important as temperature. Think of it this way: an engine that's fully warmed up and operating at the most ideal temperature, 100C, would be used to oil viscosity, let's say between as low as 10 and maybe as high as 25. So at full RPM, 7300 for our 996s, that's where we are. However, at 40C, cold start, viscosity for some 0w, 5w, and 15w might range from 70 to 125. That's a HUGE difference. Now, let's look at pour point in extreme cold. Differences between 0w, 5w, and 15w might be -54C to -39C. That's the temp the oil won't even pour out of the bottle. I don't have number for 0C, but you can see in your graph, we are in the several hundreds to thousand for viscosity number. What this means is that oil simply will not flow enough at certain temperatures and at certain RPMs. So think about starting your 996 at 0C and going to redline. It's very possible the oil will simply not flow anywhere near the volume that is does at 100C. Because an oil pump is a positive displacement pump, the volume flow has to be the same, but it won't move that fast. The excess oil has to go somewhere before something breaks.
You have to take the "multi-viscosity" thing out of the equation, but it's not as important as temperature. Think of it this way: an engine that's fully warmed up and operating at the most ideal temperature, 100C, would be used to oil viscosity, let's say between as low as 10 and maybe as high as 25. So at full RPM, 7300 for our 996s, that's where we are. However, at 40C, cold start, viscosity for some 0w, 5w, and 15w might range from 70 to 125. That's a HUGE difference. Now, let's look at pour point in extreme cold. Differences between 0w, 5w, and 15w might be -54C to -39C. That's the temp the oil won't even pour out of the bottle. I don't have number for 0C, but you can see in your graph, we are in the several hundreds to thousand for viscosity number. What this means is that oil simply will not flow enough at certain temperatures and at certain RPMs. So think about starting your 996 at 0C and going to redline. It's very possible the oil will simply not flow anywhere near the volume that is does at 100C. Because an oil pump is a positive displacement pump, the volume flow has to be the same, but it won't move that fast. The excess oil has to go somewhere before something breaks.
12-10-2018, 01:16 PM
