Tommy Posted February 11, 2015 Report Posted February 11, 2015 Hi guys! Interested to know what would be the normal range of the following oil analysis items? I have the following that comes back elevated. Lead Oxidation Copper Fuel dilution Silicon Which item(s) of the oil analysis (not limited to the above mentioned) is (are) most critical and/or telling of the engine health? Thanks Quote
Marauder Posted February 11, 2015 Report Posted February 11, 2015 Hi guys! Interested to know what would be the normal range of the following oil analysis items? I have the following that comes back elevated. Lead Oxidation Copper Fuel dilution Silicon Which item(s) of the oil analysis (not limited to the above mentioned) is (are) most critical and/or telling of the engine health? Thanks Start here: http://m.blackstone-labs.com/ReportExplanation 1 Quote
Tommy Posted February 11, 2015 Author Report Posted February 11, 2015 Is it normal to have high (mine is 900ppm) of lead since we are burning 100LL? And what's this fuel dilution business? Couldn't really find any reference on this... Quote
ArtVandelay Posted February 11, 2015 Report Posted February 11, 2015 Is it normal to have high (mine is 900ppm) of lead since we are burning 100LL? And what's this fuel dilution business? Couldn't really find any reference on this... i think that's amount of 100LL in the oil Quote
Marauder Posted February 11, 2015 Report Posted February 11, 2015 Is it normal to have high (mine is 900ppm) of lead since we are burning 100LL? And what's this fuel dilution business? Couldn't really find any reference on this... I don't remember what was considered high for lead, but yes you should see lead in your oil. If it is really high, I suspect it may be linked to your other concern of fuel dilution. Fuel dilution is the engine oil being diluted by fuel not being completely burned and ending up in the oil. Since lead is in the fuel, it would make sense that it goes up as well. Fuel dilution of crankcase oil by unburned fuel reduces lubricant effectiveness. The thinning of lubricant can lead to decreased lube film strength adding to the risk of abnormal wear. So, the first basic question is; are you leaning the plane correctly? Another possible cause is blow-by of the rings prior to combustion. Quote
Bob - S50 Posted February 11, 2015 Report Posted February 11, 2015 Increased lead may also be a measure of piston blow by. Exhaust gases getting into the crankcase and being captured by all the oil splashing around. On our last analysis our lead level was 3037 ppm while it reports the average of all users was 3360 ppm. Bob Quote
jetdriven Posted February 11, 2015 Report Posted February 11, 2015 All of these wear metals also track for hours, IE you must normalize the values seen in your oil sample for a 50-hr interval. Quote
Awqward Posted February 12, 2015 Report Posted February 12, 2015 Is it normal to have high (mine is 900ppm) of lead since we are burning 100LL? And what's this fuel dilution business? Couldn't really find any reference on this... I think I asked you this before Tom, are you based in Western Australia because the Avgas produced at Kwinana has a higher than usual TEL content....which would possibly explain your results....and also the lead fouling you mentioned previously... Quote
Guest Posted February 12, 2015 Report Posted February 12, 2015 Hi guys! Interested to know what would be the normal range of the following oil analysis items? I have the following that comes back elevated. Lead Oxidation Copper Fuel dilution Silicon Which item(s) of the oil analysis (not limited to the above mentioned) is (are) most critical and/or telling of the engine health? Thanks Lead is normally from the fuel. Copper is bad, it's part of crankshaft bearing back shells. Oxidation would suggest rust. I would suspect that fuel dilution is from unburied fuel in your oil, from overly rich mixture or from a leaking engine fuel pump. Silicon is from a dirty or leaking engine air filter or leaking alternate air door. None of these are really ideal in your oil. Clarence Quote
aviatoreb Posted February 13, 2015 Report Posted February 13, 2015 All of these wear metals also track for hours, IE you must normalize the values seen in your oil sample for a 50-hr interval. Do they all scale linearly with hours? Quote
Tommy Posted February 13, 2015 Author Report Posted February 13, 2015 I didn't use Blackstone Lab, instead I use a local oil testing lab which isn't probably specialised in aircraft engine. Hence I am asking for the normal ranges for these elements in an aircraft engine oil. Anyone has got Blackstone lab reference numbers for M20J engine using X/C 66 20-50W Multigrade? Thanks Quote
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