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Elite Engineering · 01-10-2019, 10:27 AM

Wanted to jump in here to clarify a few things,

First is what a good effective can traps is only a small amount of oil. The make up when spun in a centrifuge and then analysed you find 70% is water and acids (they do not separate once mixed), 23% is raw fuel (GDI engines experience many times the raw fuel washdown compared to the old port injection engines due to the intense pressures it is introduced at) , and only 7% is oil saturated with abrasive particulate matter.

So you never want to reintroduce this to your crankcase and this is why you do not see a similar amount of oil missing on your dipstick.

As for LSPI (Low Speed Pre Ignition) it is more common in forced induction engines than NA, but here is an example of a NA LFX piston:

But most top brands have now changed the formulation of the oil to be less explosive and this is less common all around. But ANY blend oil that is not full synthetic will still contribute to this. The fuel being introduced at 2,000-3,000 PSI is one of the reasons this occurs in both NA and FI engines, and the 2.0T GM engine when first introduced was very prone to this. GM instead of improving the crankcase evacuation system design just revised the pistons to be thicker wear they most commonly failed, at the top ring land.

01-10-2019, 10:27 AM	#81
Elite Engineering Drives: 2010 Camaro Join Date: Nov 2009 Location: Denver Posts: 1,381	Wanted to jump in here to clarify a few things, First is what a good effective can traps is only a small amount of oil. The make up when spun in a centrifuge and then analysed you find 70% is water and acids (they do not separate once mixed), 23% is raw fuel (GDI engines experience many times the raw fuel washdown compared to the old port injection engines due to the intense pressures it is introduced at) , and only 7% is oil saturated with abrasive particulate matter. So you never want to reintroduce this to your crankcase and this is why you do not see a similar amount of oil missing on your dipstick. As for LSPI (Low Speed Pre Ignition) it is more common in forced induction engines than NA, but here is an example of a NA LFX piston: But most top brands have now changed the formulation of the oil to be less explosive and this is less common all around. But ANY blend oil that is not full synthetic will still contribute to this. The fuel being introduced at 2,000-3,000 PSI is one of the reasons this occurs in both NA and FI engines, and the 2.0T GM engine when first introduced was very prone to this. GM instead of improving the crankcase evacuation system design just revised the pistons to be thicker wear they most commonly failed, at the top ring land.