Date: Fri, 25 Sep 2015 22:40:09 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Oil Temperature??
In-Reply-To: <B045181C-B56C-4F3A-B872-AA0659E948E9@gmail.com>
Content-Type: text/plain; charset="US-ASCII"
Yes and that is normal. The cooler does do too functions. It helps to warm
the oil up faster and then help keep the temperature down afterwards. The
problem is that it can only use the coolant which is at ~190 and can only
cool the oil as it goes out of the engine. So if we do best case and cool it
down to 190 when it goes back in and cools off the underside of the pistons
and picks up heat from the bearings and being pumped it will only get
hotter. An external cooler using air properly sized can benefit of getting
the oil temp towards ambient, not the hot coolant. Some engines use oil
coolers in the radiator or creatively piped to use the coolant after the
radiator to get the most benefit.
When the oil gets too hot viscosity is not the only cause for low oil
pressure. With the oil overheated the case and bearings will also be
overheated. The case material will expand making the bearings loose causing
oil pressure losses there. Rods will also increase size loosening the
bearings there. To make things worse as the oi pump case grows the clearance
there also changes and pump loses its efficiency. To me a major weakness of
the Waterboxer is the lack of thermal control of the oiling system. This is
what causes low end failures.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Angus Gordon
Sent: Friday, September 25, 2015 10:12 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Oil Temperature??
> is that stock oil cooler/heat exchanger get the heat from the coolant
> or cooling the oil via the coolant?
I can contribute a data point on the stock 2.1 oil cooler. One day this past
summer I had the cooler off my engine, so I ran my Syncro around the same
course on the same day, with and without the cooler installed. Temperature
outside was roughly 80F (27C) and the route I drove was long enough to get
the oil fully warmed up (about 30 minutes).
Without the cooler my oil temp peaked at 230F. The second run with cooler
installed showed 215F. I did notice the oil warmed faster with the cooler
installed, but didn't make any measurements on that aspect.
Angus
