Post by richard on May 13, 2012 17:11:20 GMT -5
This is a little project I have been working on for about a year. Last year about this same time I noticed that when riding my 71 xs650 in the summer heat the top of the head was getting what I felt was a little hot. Seeing that made me curious as to what it was running at? I started carrying around my hand held laser thermometer and found the temperature on the top of the head was getting up to 230F and sometimes even more. Now my experience with other air cooled bikes I have seen the top of the head get up to 25oF and in fact it is not unusual to see head temperatures of 255 or more new Harleys. To give a point of reference some oil begins to break down as it reaches 400 degrees F. I have been around a lot of industrial equipment that ran oil temps over 400 degrees, but to me any oil temp over 350F is something to be concerned about. Almost all of my bikes have had oil coolers on them which helped, but oil coolers tend to be passive in traffic and need air flow to dissipate the heat within them. I wanted a solution that would have a higher heat dissipation rate at any air flow rate and right at the source of the heat. With that in mind I decided to make some finned covers to see what was possible. Here ia what I can up with.
Since making and setting up tooling takes longer than machining parts most of the time I made several sets and variations of these finned valve covers. The jigg I made mounted four at a time.
This is one of the 4 bolt covers I made for the 447 engine. I made sets of covers for both engines with spares
This is a side view of both the two valve covers and the oil filter cover.
This is the two covers on my XS1B. I made a set of four just for this bike but so far used only two of the valve covers on the head. I didn’t want to change the bike any more than needed for this test.
This is an example of the counter bore on the XS1 covers with the bore slope set so the oil would run back into the head. I wanted a large surface area to dissipate heat as much as possible.
This is the finned oil filter cover for the 256 engine on the XS1. I only made one of these. I made 4 for the 447 because I needed one for my 82, but there are so few XS1s it didn’t seem worth making more than the one I used for my XS1B. I’m still not sure how well the finned oil filter cover will dissipate heat. I have to run it a while to see.
The end result using my laser temp meter, with the same ambient temperature of 87 degrees before and after the covers were added. Traveling around town as well as a three mile stretch at 55 mph the finned covers dropped the head temperature from 230 to 197 degrees taken at the front two valve covers. The finned oil filter seemed to have less of an effect on this trip. The crank case below the cylinders was 175 degrees before and with the finned oil filter cover I got 167 with a surface temp of the fins being at 116 degrees. These are just my initial findings and I think I could get a better assessment on a longer trip, but at this point I feel safe in saying I gained something for my effort. I think the finned oil filter cover may have more benefit with longer sustained freeway speeds. With the limited surface area inside the cover I will need the differential between the fins and the oil temp, so I’ll check the temps again on the next long trip.
Here’s the frame mockup for the 82. It will have to be reinforced in a lot of places and I’ll have to make parts for it since it will look more or less like a standard with an upper triple tree clamp for standard bars. I'm still doing the math at this point
Since making and setting up tooling takes longer than machining parts most of the time I made several sets and variations of these finned valve covers. The jigg I made mounted four at a time.
This is one of the 4 bolt covers I made for the 447 engine. I made sets of covers for both engines with spares
This is a side view of both the two valve covers and the oil filter cover.
This is the two covers on my XS1B. I made a set of four just for this bike but so far used only two of the valve covers on the head. I didn’t want to change the bike any more than needed for this test.
This is an example of the counter bore on the XS1 covers with the bore slope set so the oil would run back into the head. I wanted a large surface area to dissipate heat as much as possible.
This is the finned oil filter cover for the 256 engine on the XS1. I only made one of these. I made 4 for the 447 because I needed one for my 82, but there are so few XS1s it didn’t seem worth making more than the one I used for my XS1B. I’m still not sure how well the finned oil filter cover will dissipate heat. I have to run it a while to see.
The end result using my laser temp meter, with the same ambient temperature of 87 degrees before and after the covers were added. Traveling around town as well as a three mile stretch at 55 mph the finned covers dropped the head temperature from 230 to 197 degrees taken at the front two valve covers. The finned oil filter seemed to have less of an effect on this trip. The crank case below the cylinders was 175 degrees before and with the finned oil filter cover I got 167 with a surface temp of the fins being at 116 degrees. These are just my initial findings and I think I could get a better assessment on a longer trip, but at this point I feel safe in saying I gained something for my effort. I think the finned oil filter cover may have more benefit with longer sustained freeway speeds. With the limited surface area inside the cover I will need the differential between the fins and the oil temp, so I’ll check the temps again on the next long trip.
Here’s the frame mockup for the 82. It will have to be reinforced in a lot of places and I’ll have to make parts for it since it will look more or less like a standard with an upper triple tree clamp for standard bars. I'm still doing the math at this point
