manga_blue wrote:It had never occurred to me that oil foaming could be a factor. Mine is a standard NA8 sump, pump, pickup, etc with no extra baffles or anything like that. I installed it myself and I made bloody sure it was fault free and fitted without leaks, etc. The oil fill quantity checks out perfectly on an OEM dipstick, so I'm positive the fill level is right.
Can anyone say that oil foaming occurs in a properly built standard NA8 engine? ... Or any other B6 or BP engine for that matter?
Edit: also anal about oil gallery cleanliness in the build and oil cleanliness in refills.
oil foaming is usually caused by air introduced into the oil system"air leaks in pickup " oil cavation (spelling) types of oil (low in silicion, silicon reduces foaming)
overfilling of sump, cavation of oil pump due to design, oil starvation common in BP race engines re: dry sumping,vaccuming, scrappers or extra baffles.
I'm not going to get into any blues regarding oils for these motors, but consider the following, 237 degrees celcius at which stage the sensor melted, pistons, bearings, cams and crankshaft all servived, no galling, no pick up on anything. Everything was stuffed but the oil, the most important part of any engine survived.
My rep from Pacific Petrolium is a engineer not a salesman and so was the rep before him, both worked at Mobil and have raced in production series.
Their recommendation for Mazda BP or B6 motors, not to use synthetic oils. These are old designs from the 60/70s and modern high zinc performance oils are all that is needed to protect these motors.
So what can we do other than redesigning the whole motor or fitting dry sumps etc.
Use good oil, high in zinc and having silicon antifoaming additives.
Keep the oil cool on track.
Don't overfill it, measure the amount 3.8Lts and install and check dipstick level.
try not to over rev the motor or at least try and keep it under the red as much as you can.
Remember these aren't cosworth engines, these are motors designed for a 323/ Laser hatch/sedan, not designed to rev for 1 hour at 8000 rpm and come back the next day for more of the same, these are mass produced family car engines that date back to the 60/70s????.The fact that we can race them is testament to the designers abilities
Thats my 2c worth!!
T