Engine Oil and Torque Converters
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Engine Oil and Torque Converters
Since there has been a good thread on engine oils I need to know what to do.
My application is a desert/dune car ,3100 pounds ,427 SBC/800hp . Transaxle is a manual sequential driven by 10" torque converter. Due to packaging restrictions I am dry sumped with a 2 pressure section pump. One pump section for engine and one to feed the torque converter and a common 5 gallon oil reservoir feeds both.
Bearing clearances are approx .0028/.0025 using mobil1 15/50 due to high oil temps. Sump temps on a 100 degree day are approx 300F even with the largest Setrab cooler/fan . Most of the heat I'm sure is from the torque converter. After reading the current oil discussion I'm thinking I might be able to lower the sump temps using a lighter oil. Maybe 10/40? 10/30??
Would not both the engine and converter both generate less heat with a thinner oil?
I'm open to any opinions.
My application is a desert/dune car ,3100 pounds ,427 SBC/800hp . Transaxle is a manual sequential driven by 10" torque converter. Due to packaging restrictions I am dry sumped with a 2 pressure section pump. One pump section for engine and one to feed the torque converter and a common 5 gallon oil reservoir feeds both.
Bearing clearances are approx .0028/.0025 using mobil1 15/50 due to high oil temps. Sump temps on a 100 degree day are approx 300F even with the largest Setrab cooler/fan . Most of the heat I'm sure is from the torque converter. After reading the current oil discussion I'm thinking I might be able to lower the sump temps using a lighter oil. Maybe 10/40? 10/30??
Would not both the engine and converter both generate less heat with a thinner oil?
I'm open to any opinions.
Re: Engine Oil and Torque Converters
The lower viscosity oil will have a lower specific heat capacity and thus won't run as hot and easier to cool off. It would be a very small improvement as like you said, much of that heat is from the converter. That makes me iffy about lower viscosity here.
Mobil 1 15W-50 is a group III base oil with an Infineum SP add pack and ~50% more ZDDP top treatment. It's a decent oil, but I would rather see a stouter oil.
Is this engine on methanol or E85?
Mobil 1 15W-50 is a group III base oil with an Infineum SP add pack and ~50% more ZDDP top treatment. It's a decent oil, but I would rather see a stouter oil.
Is this engine on methanol or E85?
Re: Engine Oil and Torque Converters
e85. There is no odor of ethanol in the oil at all. I don't believe I have any dilution from it. Like you,I am iffy about going to a lower viscosity in this application. What is your suggestion in a stouter oil?
Re: Engine Oil and Torque Converters
Noted. You're running it hot enough that I wouldn't be worried about fuel wash or dilution issues with E85.
In a stouter oil, I'd be looking at an oil that can take the heat better. An oil that'll be right at home at 300°F. A majority group IV polyalphaolefin (PAO) synthetic with smaller blends of group V polyol ester (POE) and group V alkylated naphthalene (AN) would be ideal as you'd have good shear stability and service life from the PAO, good solubility and high temp stability from the POE, and reduced friction and high temp stability from the AN. The additive package would need top treatment for more friction reducers and better foam/aeration prevention.
The converter changes everything. It's the main heat pump here over the bearings. I would actually advice sticking with a 50 grade or even going up to a 60 grade.
I'll PM you.
In a stouter oil, I'd be looking at an oil that can take the heat better. An oil that'll be right at home at 300°F. A majority group IV polyalphaolefin (PAO) synthetic with smaller blends of group V polyol ester (POE) and group V alkylated naphthalene (AN) would be ideal as you'd have good shear stability and service life from the PAO, good solubility and high temp stability from the POE, and reduced friction and high temp stability from the AN. The additive package would need top treatment for more friction reducers and better foam/aeration prevention.
The converter changes everything. It's the main heat pump here over the bearings. I would actually advice sticking with a 50 grade or even going up to a 60 grade.
I'll PM you.
Re: Engine Oil and Torque Converters
Mobil 1 has always been my affordable, easy to find (Walmart) Go-To oil! It works great in air cooled engines as well as hotrods.
This being said, it has a new formulation. The SN rated (15w50 in RED letters) is the old formulation, and the new one has 15w50 in BLACK letters. I believe it is SP. The old 15w50 has 1300 ppm Zinc. The new 15w50 has 1100, as well as slightly less other anti wear additives. Lake Speed did a video that can probably be looked up. I recently stocked up on the Red label.
The standard Mobil 1 oils are all around 800 ppm Zinc.
https://www.youtube.com/watch?v=UQZzKjlu0iE
This being said, it has a new formulation. The SN rated (15w50 in RED letters) is the old formulation, and the new one has 15w50 in BLACK letters. I believe it is SP. The old 15w50 has 1300 ppm Zinc. The new 15w50 has 1100, as well as slightly less other anti wear additives. Lake Speed did a video that can probably be looked up. I recently stocked up on the Red label.
The standard Mobil 1 oils are all around 800 ppm Zinc.
https://www.youtube.com/watch?v=UQZzKjlu0iE
Re: Engine Oil and Torque Converters
What Lake Speed was getting at in his video, was that the newest oil grade (SP) has had a lot of its additives changed for Direct Injection engines. The older SN designation has more detergents, and possibly more anti-wear additives... at least the Mobil 1 15w50 variant.
Re: Engine Oil and Torque Converters
Right. Calcium sulfonate has been found to increase the frequency of low speed pre-ignition (LSPI) events in gasoline direct injected engines. Reducing the Ca to <1500 ppm helps prevent that issue. To make up for it, magnesium sulfonate is increased. Magnesium is neutral to LSPI.n2omike wrote: ↑Tue Oct 18, 2022 12:30 pm What Lake Speed was getting at in his video, was that the newest oil grade (SP) has had a lot of its additives changed for Direct Injection engines. The older SN designation has more detergents, and possibly more anti-wear additives... at least the Mobil 1 15w50 variant.
However, this is a crutch. ZDDP has a positive affect on LSPI and reduces the events at higher concentrations. The same with a common friction modifier MoDTC.oi Esters also reduce quench LSPI. The issue is both additives contain sulfur and ZDDP has phosphorus, both of which are limited by API SP. If you increase ZDDP to ~1200 ppm P and MoDTC to ~400 ppm Mo, you could run 3000 ppm Ca with no LSPI issues while having better anti-wear protection, lower friction, and longer service life to boot. This is one of those times where API standards hurt oil performance as much as they help. This is where your smaller, boutique oil blenders take over.
I was actually talking to Lake this morning about this very thing. He's got some more videos coming soon on the topic.
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Re: Engine Oil and Torque Converters
Speaking of LSPI. I run a tuned ecoboost and notice some big knock counts under light tip in throttle, mainly after a cold start. Which I would suspect would be a time when it’s least likely. My tuner has looked at the logs and said everything looks good and it’s most likely just noise. I run Mobil 1 5W30 with the Dexos spec. Which is supposed to help combat LSPI. Do knock sensors pick up LSPI?
I’m most likely going to try a different oil, if anyone has any recommendations. Unless the Dexos spec is ok. Seems GM has higher standards than Ford. They make no mention of it and suggest their synthetic blend motorcraft stuff still. I change it pretty regularly. Between 3K-5k miles. I don’t see abnormally high sump temps but worry about fuel dilution and break down contributing to LSPI so change it often and keep it fresh. Makes a ton of torque from 2000rpm on up. I often wonder if the viscosity is too light for the load but no issues at all apparently.
I’m most likely going to try a different oil, if anyone has any recommendations. Unless the Dexos spec is ok. Seems GM has higher standards than Ford. They make no mention of it and suggest their synthetic blend motorcraft stuff still. I change it pretty regularly. Between 3K-5k miles. I don’t see abnormally high sump temps but worry about fuel dilution and break down contributing to LSPI so change it often and keep it fresh. Makes a ton of torque from 2000rpm on up. I often wonder if the viscosity is too light for the load but no issues at all apparently.
Re: Engine Oil and Torque Converters
The Mobil 1 5W-30 isn't too low of viscosity for that engine. It does shear some (as all shelf oils do) and lose viscosity with dilution. I've seen a lot of 5W-30 oils end up in 5W-20 territory after 5,000 miles, going from 10.5 cSt down to ~8 cSt. You have to shorten the oil change intervals with GDI due to the dilution issue.Roundybout wrote: ↑Tue Oct 18, 2022 2:16 pm Speaking of LSPI. I run a tuned ecoboost and notice some big knock counts under light tip in throttle, mainly after a cold start. Which I would suspect would be a time when it’s least likely. My tuner has looked at the logs and said everything looks good and it’s most likely just noise. I run Mobil 1 5W30 with the Dexos spec. Which is supposed to help combat LSPI. Do knock sensors pick up LSPI?
I’m most likely going to try a different oil, if anyone has any recommendations. Unless the Dexos spec is ok. Seems GM has higher standards than Ford. They make no mention of it and suggest their synthetic blend motorcraft stuff still. I change it pretty regularly. Between 3K-5k miles. I don’t see abnormally high sump temps but worry about fuel dilution and break down contributing to LSPI so change it often and keep it fresh. Makes a ton of torque from 2000rpm on up. I often wonder if the viscosity is too light for the load but no issues at all apparently.
Re: Engine Oil and Torque Converters
Couldn't agree more about the converter being the vast majority of the heat generated. Drop too much rpm and it will rise quickly. Gotta keep it hooked up.RDY4WAR wrote: ↑Tue Oct 18, 2022 10:26 am Noted. You're running it hot enough that I wouldn't be worried about fuel wash or dilution issues with E85.
In a stouter oil, I'd be looking at an oil that can take the heat better. An oil that'll be right at home at 300°F. A majority group IV polyalphaolefin (PAO) synthetic with smaller blends of group V polyol ester (POE) and group V alkylated naphthalene (AN) would be ideal as you'd have good shear stability and service life from the PAO, good solubility and high temp stability from the POE, and reduced friction and high temp stability from the AN. The additive package would need top treatment for more friction reducers and better foam/aeration prevention.
The converter changes everything. It's the main heat pump here over the bearings. I would actually advice sticking with a 50 grade or even going up to a 60 grade.
I'll PM you.
Have considered a heavier oil but don't really like the idea too much. I'll follow your suggestion in the pm and see what he says.
Re: Engine Oil and Torque Converters
I've been running the M1 15w50 for a couple years now and have no signs of any issues with TC or engine. That said I'd like to get the temps down 20-30 degrees at the point of generation instead of adding more cooling..somehow.n2omike wrote: ↑Tue Oct 18, 2022 11:47 am Mobil 1 has always been my affordable, easy to find (Walmart) Go-To oil! It works great in air cooled engines as well as hotrods.
This being said, it has a new formulation. The SN rated (15w50 in RED letters) is the old formulation, and the new one has 15w50 in BLACK letters. I believe it is SP. The old 15w50 has 1300 ppm Zinc. The new 15w50 has 1100, as well as slightly less other anti wear additives. Lake Speed did a video that can probably be looked up. I recently stocked up on the Red label.
The standard Mobil 1 oils are all around 800 ppm Zinc.
https://www.youtube.com/watch?v=UQZzKjlu0iE
Re: Engine Oil and Torque Converters
Due to layout it would not be easily added but it COULD be done. I also have coolant temps running @220 when 100 degrees ambient. RPM is between 3-7K up and down constantly. Will run cooler oil and coolant temps about equal to the drop in ambient temps. Question: if I run a oil to water exchanger will I see an increase in coolant temps? I would assume I would and I can't have that. What do you think?