Id like to know why piston squirters are recommended or even mandatory for Nikasil plated all aluminum cylinders when they expand more than biral or cast iron cylinders? Does this make sense, should the opposite be true?
Id like to know why piston squirters are recommended or even mandatory for Nikasil plated all aluminum cylinders when they expand more than biral or cast iron cylinders? Does this make sense, should the opposite be true?
Any guesses?
My guess would be that the squirters are aimed at the crown of the piston and this amounts to a form of oil cooling. The heads and cylinders are air cooled directly by cast fins. The pistons also need to be cooled, and oil squirters are the first part of the process.
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I added them to my 69S motor during the rebuild, why not? Added hydro tensioners too.
Our cars are really oil cooled, with some secondary cooling from air, so I suspect that this is correct. The specific heat capacity of 20W50 oil is around 20000 J/kg degC while air is 1000 J/kg degC. The flowing oil does a lot more to cool the motor than the air.Originally Posted by davep
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I understand the function of the squirters although I wonder how hard you have to drive your car to achieve the quoted 50 degree C improvement in piston temp. I’m talking about higher expansion rates for aluminum vs. biral cylinders. If the biral cylinders expand less then why are squirters required for nicasil cylinders? Seems like the pistons in lower expansion biral cylinders need the cooling more not less. My 2.5 is definitely air cooled, a later fan pulley with an early crank pulley is stepping up the fan speed, that and no engine mounted oil cooler keep oil too cool to open the front (troutman) thermostat for the cooler. Only time the front cooler gets warm is when the car sits at an idle on a hot day.
Last edited by 66S; 11-27-2024 at 11:30 AM.
66S, what temps are you seeing after a spirited drive? I see 190F with a non trombone 2.2 MFI motor. That's assuming the gauge is correct. Haven't bought an infrared thermometer yet. Squirters just allow for the oil to be part of the heat sink.
Around 200 deg.
If you've got an infrared what brand and where do you point it? I'll buy that one for an apples to apples comparison. It could be your 2.5 throws off more heat than my 2.2.
I just read the oil temp gauge, no other measurement. I have a front mounted tank and about 15 qts off oil. It would be an apples to oranges comparison with my stepped up fan speed and no engine mounted cooler.
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