Johnny2Bad

Interesting Patent application (not yet granted by USPTO) that addresses a condition encountered in boosted engines (turbocharged, supercharged) referred to as Low Speed Pre-Ignition (LSPI). Essentially magnesium and calcium content in the oil (start with the summary, scroll down) to reduce / eliminate detonation below 3,000 / moderate load conditions.

An interesting read.

Lubricants with Magnesium and Their Use for Improving Low Speed Pre-Ignition - Afton Chemical Corporation

tyhackman15

Isn't this mainly an issue with direct injection motors? Would be great for any of the modern DI turbo's, but doubt our miatas need it.

cal_len1

I would be curious if one had to design a specific amount of oil consumption to get the desired effect.

LukeG

Haven't the F1 teams been doing this for a while?

Mobius

iTrader: (2)

The F1 teams, the clever ones, were using oil as a combustant. Meaning, fuel flow was limited to a rate of 100kg/hour. Until this year (2018) oil was not considered as a contributor to burn rate. What the clever teams were doing, was making the oil supply massive, and the oil itself something we mortals will never see in our lifetimes, and burning the oil itself as a combastant to add energy.

They all got busted on that this year, can't burn oil as a fuel and claim otherwise. Thus the spray of oil (or the barely visible burning glow) from Ferrari they kept discussing at Bahrain this weekend. Make no mistake the other teams at the pointy end all did it too.

engineered2win

Wut?

High calcium content in oil has been proven to be a contributor for LSPI.

I use a special high calcium blend of oil specifically to generate superknock for combustion research. The only change in the oil from the mass production blend is calcium, and just increasing the calcium increases superknock occurrences on the order of about 5x that of standard oil.

I wouldn't be worrying about SK on a Miata without a positive displacement blower. You really need to have high blowby, without a catch can, running <2000rpm @ >1 bar, with high intake manifold air temp to even get in the SK occurrence area. There is no SK above about 3000rpm. If you are getting SK, get a catch can or just freaking downshift.