Winker varieties
Posted by:
Kelly (IP Logged)
Date: February 23, 2008 07:41PM
The winker on the Marshall Collection's 1918 735 has not been winking. It's definitely oiling, because there's plenty in the water tank & condenser. Unfortunately the people who have driven it recently don't recall if the winker is always showing brown or always showing the plunger face.
So I took a look into it last Tuesday - first time I had seen the inside of one. The plunger is an easy fit in the bore; in fact it rocks slightly more than I'd expect, but doesn't seem terribly loose. The spring seems very light. Spring pressure is presumably related to the winker's behavior, so we went to the parts bin and pulled out the spare winkers. All of them had a spring that was much stronger than the one in the 735.
Tom suggested that we take a look at the 1916 725, because its oiling system should be similar to the 735 - condensing car, thinned cylinder oil. (The 1922 740 uses a pressure gauge to monitor oil feed - no help there.) The 725 has the same light spring. As far as I can tell, it is exactly the same spring - slightly tapered on the ends. BUT - the hole in the plunger is larger than that of the 735.
I wasn't sure of the period of time when SMCC specified the thinned oil, so I thought perhaps the 725 was a transition and was oiled like the noncondensers. I then looked at the 607, the 76, and the 87 (1914, '13, and '12). They all had the heavy spring and the large plunger hole.
So I was unable to establish a pattern. Here's the data:
735 - - - - - - - small hole, light spring
spares - - - - - -small hole, heavy spring
725 - - - - - - - large hole, light spring
noncondensers - large hole, heavy spring
What's the real equation for oil weight, plunger hole size, and spring strength, to yield a good solid wink?
Kelly