Eventually I have a replacement for.my n54 and putting a real M engine in my 1m
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Best aftermarket oil thermostat solution for N54?
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220f is a hotrod magazine quote that gets punted around. Oil manufacturers will tell you its a snick under 200f. Then upto 212f 100C) is happy days operating viscosity(rated) above which you have wriggle room to maintain that 30 or 40 rating or whatever it has viscosity wise till it hits a temp where it thins the oil and you gradually lose thickness.
Oil weight has alot to do with how fast oil heats up and also sheds heat too.
This vid interviewing a redline chap I watched a few years back does a great job to demsitify oil and probably should be a sticky for the forum to help set the basis for a good discussion (even covers bmw quirks like vanos). Covers more of the above points :
I ran my cars for years that way without issue, but i would exhaust all other avenues first before changing the thermostat
Having an electronic thermostat that you could.dial in your ideal temp would be best
Now that's something I'd pay for.
Having an electronic thermostat that you could.dial in your ideal temp would be best
Now that's something I'd pay for.
Those are all or nothing, once you open it you will get a huge surge of cold oil from the oil cooler which is still at cold temps and that is not good for the bearings since viscosity would still be so high.
Thats why improved racings thermostat is so good, high unrestricted flow and you can pick the temp of the thermostat.
I'm in the improved racing thermostat camp myself. The temp control is great, super reliable and potentiallu removes pretty decent oil flow restriction that a modified or stock thermostat represents (though you can debate that one). Then just getting the right oil cooling needed and oil weight selected based on how much heat you are bashing into the oil Vs viscoscity needed. The bmw vanos situation is interesting that the redline oil chap raised,. The potential need to bump up viscosity selection to keep it working well under race conditions.
None the less, its worth understanding that your bearing surfaces are going to be somewhere 80 to 100f+ hotter than the pan/pipe oil and more hot there equals more wear , less life. But, you know more horsepower is same same, so its something to accept.
None the less, its worth understanding that your bearing surfaces are going to be somewhere 80 to 100f+ hotter than the pan/pipe oil and more hot there equals more wear , less life. But, you know more horsepower is same same, so its something to accept.
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This is hands down the nicest thermostat option for the n54. Integrated 185*F thermostat and threaded for AN.
www.mosselmanturbo.com
Mosselman Oil Thermostat N54
Keep your BMW N54 engine safe and cool with the Mosselman Oil Thermostat N54. Instead of opening at 105℃, the MSL Thermostat opens at 85℃ which results in an operational oil temperature 20℃ lower than OEM.
Judging by that little blueprint of the internals at the bottom of their page it uses the same thermostat design as oem, so it's still going have restrictions.This is hands down the nicest thermostat option for the n54. Integrated 185*F thermostat and threaded for AN.
Mosselman Oil Thermostat N54
Keep your BMW N54 engine safe and cool with the Mosselman Oil Thermostat N54. Instead of opening at 105℃, the MSL Thermostat opens at 85℃ which results in an operational oil temperature 20℃ lower than OEM.
It is a very nice looking piece and very clean, but it will not hold up to a delete plate + improved racings thermostat in terms of performance.
And they never answer any emails so customer.support is useless.
You can have the best product but is usually let down by their own laziness or arrogance.
You can have the best product but is usually let down by their own laziness or arrogance.
who mossel?
I know improved racing has excellent coms, they have great phone support, great email support, and even their social media (which is not known for technical support in most companies as it is run by marketing people) has excellent support and can even help with technical questions.
BTW does anyone know where to buy thermostat delete plates now a days for the n55? Motiv has been sold out forever.
After seeing the Mosselman thermostat in person and looking inside the piece, it doesn't appear to have any restrictions that would be smaller than the 10AN hose size. It seems they took the stock design and improved upon it (speculation). Fair point about their customer service though but I haven't had to deal with that yet. Much cleaner install for a double oil cooler (shorter direct lines/less fittings) which is really the main reason I went with it, aside from the fact that it's literally designed for our engines lol.
But keep in mind, if it cools the engine as it's supposed to it isn't any better or worse than the others - it functions the same.
But keep in mind, if it cools the engine as it's supposed to it isn't any better or worse than the others - it functions the same.
Yeah looking at something online doesn't show the fully picture so it could be alot less restrictive but it won't be as unrestrictive as improved racing.
Also how much it flows to the cooler when its cold? Is can't be only on at or near the trigger point?
Mosselman is a 'neat' compact solution for a standard thermostat with different opening temp. Which could be great for certain applications on mild street car setups. I still prefer the bypass method as superior for oil circulation, temp control and ensuring the thermostat is out of the oil flow path for anything more hard core.
Some questions for them I would be asking are;
* What is the max flow temperature rating when the oil pump is at speed and its fully open? (it will be higher than 185f)
* In terms of flow (easy question) does it flow unrestricted 20GPM ?
Note that all the standard earls and other external offerings in 10AN style do. This helpful to reduce pumping restrictions when you need to move the increased volume and distance of oil over longer lines and single or multiple cooling cores.
Some questions for them I would be asking are;
* What is the max flow temperature rating when the oil pump is at speed and its fully open? (it will be higher than 185f)
* In terms of flow (easy question) does it flow unrestricted 20GPM ?
Note that all the standard earls and other external offerings in 10AN style do. This helpful to reduce pumping restrictions when you need to move the increased volume and distance of oil over longer lines and single or multiple cooling cores.
The factory thermostat is more than capable of cooling the oil and you dont need large volumes of oil going through it, you need a constant steady flow so the oil cooler can do its thing.
A bigger cooler.will be far more beneficial than a thermostat, i would rather run two oil coolers and the stock thermostat than a racing thermostat on the street.
A bigger cooler.will be far more beneficial than a thermostat, i would rather run two oil coolers and the stock thermostat than a racing thermostat on the street.
The S55 has an oil cooler that's probably twice the size of the stock N54/N55 units? Probably fair to assume they wouldn't have done that if they could have simply "upgraded" the thermostat instead. That being said, the S55 does have a lower set point thermostat, here's the quote from BMW:
"Due to the higher engine performance, a large heat quantity must be dissipated by the engine oil cooler. The opening range of the thermostat is therefore earlier than the N55 engine."
Maybe it also has something to do with the S55 being sleeved as well. Might need to keep the fluctuations in temperatures more tight.
Different engines, different needs that was designed for that engine.
In the end its not a thermostst issue but the heat exchanger, the longer the oil spends in there the more heat it looses.
Having a fast flow thermostat is actually detrimental to what the exchanger needs to do.
Think of it like an ic, it works the same way
The bigger the surface area the better, what is really needed is a cooling solution that can heat up as fast as possible and once it reaches the target temp its stays there as long as possible before its oversaturated.
The thermostat is not the problem.
In the end its not a thermostst issue but the heat exchanger, the longer the oil spends in there the more heat it looses.
Having a fast flow thermostat is actually detrimental to what the exchanger needs to do.
Think of it like an ic, it works the same way
The bigger the surface area the better, what is really needed is a cooling solution that can heat up as fast as possible and once it reaches the target temp its stays there as long as possible before its oversaturated.
The thermostat is not the problem.
Clearly a larger cooler area is going to provide a better cooling performance I didn't argue against that. But when you are chasing every possible ounce of performance you have to look at every single possible angle.
I like many others believe the stock thermostat unit is too restricting hence why we do see small gains just deleting it and running thermostatless or high flow thermostats. We see these gains in the car taking longer to limp out overall.
The peak temperatures will still be bottle necked by the maximum surface area of the oil cooler core that is a given.
But since the stock thermostat opens at such a high temperature and flows too slowly you see a drop in oil temperature when full flow hits and then the oil cooler gets heat soaked shortly after since opening oil temps are too high and you hit limp mode soon after. With an upgraded thermostat you can choose trigger temperature to be lower so instead of waiting until the last minute to open you start opening soon after operating temperature is met so you essentially buy yourself more time to hit limp mode, which is another benefit of having an aftermarket thermostat.
Your analogy of the intercooler is not perfect.Yes the longer oil spends in the oil cooler the more temperature it looses, but the rest of the oil in the loop does not get cooled and just sits there while more hot oil accumulates waiting to be cooled. You don't want the thermostat to be the restrictor to keep oil in the cooler longer you want the oil cooler to do that hence why you buy double pass and triple pass oil coolers, oil coolers are not intercoolers. A better comparison is to the radiator which is also multi pass. What happens when coolant temps rise? The pump duty cycle increases to cycle more coolant and drop those temperatures at the source and throughout the reservoir of coolant, you don't see pump duty cycles drop to keep coolant in the radiator longer...
At the end of the day it is up to you what thermostat you want my experience is based off of observing what racers use and some custom oil cooling I did on my m235i years ago (IIRC a thermostat delete and larger oil coolers), I also only offered the improved racing thermostat as a suggestion because this thread asked for a thermostat suggestion.
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