New engine in my boat, now has about 90 hours overall. Last UOA showed somewhat high manganese- about 98 when the universal average is 2. What would be the source for manganese in the absence of other problems ?
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7.4L GM marine application; high manganese
- Thread starter rubberchicken
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4WD
$50 site donor 2024
Engine type and oil ?
I would guess still breaking-in. At how many hours was the oil change done that you did the UOA on?
Manganese is an abrasive that is found in break-in oil.
Often matched with molybdenum for scuffing and providing an area for the moly to adhere.
Often matched with molybdenum for scuffing and providing an area for the moly to adhere.
MolaKule
Staff member
Someone dumped in some octane booster in the fuel, methylcyclopentadienyl manganese tricarbonyl.
Never heard of this compound ever being used in engine oils.
Never heard of this compound ever being used in engine oils.
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Originally Posted by 4WD
Engine type and oil ?
I will try to answer a bunch of questions-
Engine is GM 454 7.4 L rated at 310 hp- new not rebuilt, 2017. Oil was Amsoil 20w50. oil use interval was about 40 hours, generally in the 3200 to 4000 rpm range. Marine engine with closed cooling. I did not use any specific break in oil. I have used some octane booster on occasion- Lucas brand.
Molakule: I found these ingredients- from the Lucas MSDS https://lucasoil.com/pdf/SDS_Lucas-Octane-Booster.pdf
Ingredient name % CAS number
Solvent naphtha (petroleum), medium aliphatic 30 - 60 64742-88-7
Tricarbonyl(methylcyclopentadienyl)manganese 1 - 5 12108-13-3
Engine type and oil ?
I will try to answer a bunch of questions-
Engine is GM 454 7.4 L rated at 310 hp- new not rebuilt, 2017. Oil was Amsoil 20w50. oil use interval was about 40 hours, generally in the 3200 to 4000 rpm range. Marine engine with closed cooling. I did not use any specific break in oil. I have used some octane booster on occasion- Lucas brand.
Molakule: I found these ingredients- from the Lucas MSDS https://lucasoil.com/pdf/SDS_Lucas-Octane-Booster.pdf
Ingredient name % CAS number
Solvent naphtha (petroleum), medium aliphatic 30 - 60 64742-88-7
Tricarbonyl(methylcyclopentadienyl)manganese 1 - 5 12108-13-3
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4WD
$50 site donor 2024
Can manganese bronze valve guides do that? The booster ? what else could it be …?
If the high manganese was due to the octane booster, it sort of implies that there is a lot of blowby. This does not seem to be the case. I am not familiar with manganese bronze valve guides, but I would think that I would also see high copper. Of all the theories I think the octane booster has the most merit. I am going to try to avoid using the octane booster and see what the results are at next UOA, and I might call Blackstone for advice.
Originally Posted by rubberchicken
If the high manganese was due to the octane booster, it sort of implies that there is a lot of blowby. This does not seem to be the case. I am not familiar with manganese bronze valve guides, but I would think that I would also see high copper. Of all the theories I think the octane booster has the most merit. I am going to try to avoid using the octane booster and see what the results are at next UOA, and I might call Blackstone for advice.
98 ppm is does not indicate blow by. It's from a fuel source.
If the high manganese was due to the octane booster, it sort of implies that there is a lot of blowby. This does not seem to be the case. I am not familiar with manganese bronze valve guides, but I would think that I would also see high copper. Of all the theories I think the octane booster has the most merit. I am going to try to avoid using the octane booster and see what the results are at next UOA, and I might call Blackstone for advice.
98 ppm is does not indicate blow by. It's from a fuel source.
MolaKule
Staff member
Consider this:
Any organo-chemical compound in the fuel that has been partially combusted will diffuse into the oil so that during the next oil-control ring "scraping" on the downstroke, the oil will contain that organo-chemical compound.
So unless you have a real knock problem, don't use an Octane Booster.
Any organo-chemical compound in the fuel will simply contribute to ash deposits on the plugs, valve-stems, and piston crowns.
Any organo-chemical compound in the fuel that has been partially combusted will diffuse into the oil so that during the next oil-control ring "scraping" on the downstroke, the oil will contain that organo-chemical compound.
So unless you have a real knock problem, don't use an Octane Booster.
Any organo-chemical compound in the fuel will simply contribute to ash deposits on the plugs, valve-stems, and piston crowns.
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can i get an AMEN?
Originally Posted by sunruh
can i get an AMEN?
Huh?
can i get an AMEN?
Huh?
Originally Posted by MolaKule
Consider this:
Any organo-chemical compound in the fuel that has been partially combusted will diffuse into the oil so that during the next oil-control ring "scraping" on the downstroke, the oil will contain that organo-chemical compound.
Further, the fuel close to the cylinder walls is absorbed into the residual oil film on the intake stroke, and evaporated back out with the heat from the power and exhaust strokes.
The MMT has a vapour pressure 50 times lower than gasoline typically has, so will tend to accumulate in the ring belt oil (and hence back to the sump).
Huge blowby is not necessary to transport it.
Consider this:
Any organo-chemical compound in the fuel that has been partially combusted will diffuse into the oil so that during the next oil-control ring "scraping" on the downstroke, the oil will contain that organo-chemical compound.
Further, the fuel close to the cylinder walls is absorbed into the residual oil film on the intake stroke, and evaporated back out with the heat from the power and exhaust strokes.
The MMT has a vapour pressure 50 times lower than gasoline typically has, so will tend to accumulate in the ring belt oil (and hence back to the sump).
Huge blowby is not necessary to transport it.
Octane booster in a marine 454? They run 160° thermostats and have low compression ratio. May as pour the booster into the bilge for all the good it will do.
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