Date:         Wed, 14 Oct 1998 07:45:59 -0700
Reply-To:     Vanman <mckayaa@OIT.EDU>
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Vanman <mckayaa@OIT.EDU>
Subject:      more on engine braking
Comments: To: vanagon@vanagon.com
Content-Type: multipart/alternative;

After having heard this arguement for the last couple of days, I decided to put in my own take on this issue.

1. Engine braking is required with these vans: I have an 85 GL and live right next to the Cascade mountain range in Oregon.  Less than a week ago I went to go visit a college friend on the other side of the range (Klamath Falls to Ashland via 66).  Coming down into the valley that Ashland is in, the road turns into a steep, downhill, slolom track.  Half way down the hill, my brakes had faded to almost nothing, requiring me to mash on the brakes, throw it into second, and do 30mph down the rest of the hill, letting my engine do all of my braking, and being content with 30 mph instead of 35-40mph.  Without the engine braking, I would have flown over the edge (there were no guard rails).

2. It is the air cooled engines that can be damaged by the engine braking.  This is due to the engine coming to very high temps while going up a mountain pass, and then the rapid cool down that comes with the engine braking going down the other side of the pass causes the metals in the engine to contract rapidly, mainly the cylinder liners cooling and contracting faster than the pistons, causing excessive wear and tear on the pistons and liners.  This is where the rumor about engine braking being bad for your engine started.  The water cooled engines have the water jackets and thermostats to maintain engine temp., therefore avoiding the rapid cool down problems.

mckayaa@oit.edu
college student in mechanical engineering at Oregon Institute of Technology
'85 vanagon GL

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