Blocking Hear Riser

[RalphG]

Gene1949,

The exact reason I blocked mine off was too cut off the heat going to the carburetor, I did the metal tabs with the edge bent up, rather than the penny's, so I could install and remove them with needle nose pliers, after just loosening the bolts. Just in case I didn't like it. 13 years later and they are still in. Here is the before and after blocking off the heat riser, at the same location.

And you don't have a problem with carburetor icing on a cold start in damp weather? Mine is stock and clean wide open passages just for that reason. I've never had a problem with vapor lock but then I don't drive if the temp is 90 degrees either.

 

[Merc Cruzer]

RalphG,

I can see that might be an issue where "cold and damp" conditions would exist. As you will remember I am at 8300 ft in Colorado. So cold we have but damp, well the current temperature is 45 degrees and the humidity is 13%. If it rains we are lucky to get up to 45%- 50% humidity. We are known as High Desert.

I grew up in Michigan, so I know what cold and high humidity is. There the ice in the gutters on the street, stayed until Spring. The snow on the side of the road used to get very dirty, but here it is gone before it can get dirty. Here, the snow doesn't melt on,the highways it evaporates. When I drive the car on the dry days, in the winter months, and the temperature is around 40 degrees, it loves it.

But when summer comes and the humidity is in the single digests and the temperature is in the 80's, then you deal with vapor lock. One of the more common solutions, is to stop by a store and buy a bag of ice and put it on the fuel line and carburetor.

With the amount of heat generated under the hood, I am surprised the carburetor would ever ice. So I guess you are not going to cut louvers in you hood any time soon . Thanks for the insight. But on the other hand, you are lucky enough to have long stretches of flat roads, where as when I go to Denver and return home, I am climbing 3,000 feet in 13 miles. At times it can become very difficult to pass a slow moving semi, when you are stuck behind it and waiting for a gap in traffic. Trying to tune a 50's carburetor for that can be a challenge, to say the least.

 

[RalphG]

RalphG,

I can see that might be an issue where "cold and damp" conditions would exist.
With the amount of heat generated under the hood, I am surprised the carburetor would ever ice. So I guess you are not going to cut louvers in you hood any time soon . Thanks for the insight. But on the other hand, you are lucky enough to have long stretches of flat roads, where as when I go to Denver and return home, I am climbing 3,000 feet in 13 miles. At times it can become very difficult to pass a slow moving semi, when you are stuck behind it and waiting for a gap in traffic. Trying to tune a 50's carburetor for that can be a challenge, to say the least.

Not sure I've ever had to pass anybody with my Merc. Unless its a farm tractor. I remember watching some of your driving videos. Very interesting. We are just over 2000 feet elevation here.