Monday, March 7, 2011

Volume plus pressure

Though I flunk math a couple of times in my life, understanding the problem was not very difficult....just a little friction.
The twin turbos on this ride burned up.  American turbos don't require as much oil as the stock ones, and with a high volume oil pump, this 3.1 litter is pumping 80 lbs cold.
The diagnose from the turbo company was "lack of oil"  What !!!  at the end of this equation, I think somebody made a mistake, but before we start asking for heads to roll, let's check our own stuff first;  All lines are fine, all fitting are restricted as recommended, we have plenty of pressure, Ok, so remove all restriction and increase the diameter of the feeding hoses.....the important thing here is, give the customer what he came here to get, a rumbling twin turbo.  A couple of days after he took delivery of the car, he called back.
Have you seen spies movies ??  they all have a button to release a smoke screen to get away.....so much oil pressure, the turbos were squirting it out of sides and into the tail pipe;  Now for the big dilemma, restrict the oil flow and risk the turbos, not an option, the problem wasn't volume alone, it was volume with that kind of pressure.
There is a company near by that makes all kind of check valves, and they had one that allows only 20 lbs of pressure, this might work, we tested it, and documented the test, it has good pressure, good flow, now for a test drive.   Oil + temperature = low viscosity.  The pressure dropped to a very uncomfortable level.
One fun thing about my job is that I get to take things apart just to see how they work,  Inside the valve there were springs, rubber seals and two machined fittings,  replaced the spring, drilled a couple of holes and machined a little more.  The result: the proper volume at the proper pressure......so far so good.

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