Some info for David.
I cleaned up and measured the pull strength of three different hood springs. Not the most precise measuring tools were used, but I pulled them the 1-1/4" distance that is their full travel when opening and closing the hood, and noted the maximum reading. Measurements were taken with a digital luggage scale.
The best spring, no rust and heavily painted gray, measured in excess of 110 lb, as that's the limit of the scale. It had nearly reached the full stretch before it went over scale so I'm sure it's somewhere close to 110. The next best, also no rust and heavily painted, was 108 lb. The last had some surface rust that was beginning to etch the surface of the entire spring. It measured 87 lb.
I have two more springs still attached to the hinges that I will measure when I get around to removing and cleaning them, but they too have some rust, so I'm guessing they will also be weaker. They are still on the parts car and the hood sags somewhat.
Interesting. What type of scale did you use to measure them? I would really like to know the difference between the Dodge and Plymouth springs. Let me know how you did the test and I will check out the extra sets of springs that I have or I can send you the set I believe to be Dodge springs.
ReplyDeleteI didn’t attempt to recreate the exact configuration of the installed parts, but rather I compared the performance of the different springs under the same conditions. I secured one end of the spring to a solid mount and used a luggage scale to pull test them. The amount of stretch as installed on the hood hinge is about 1-1/4”, so that’s what I used for a test point. If I had used the full movement the spring is exposed to during actual use, the scale would have indicated an error as all the springs would have exceeded the scale’s range. My digital luggage scale has a maximum indication of 110 lb, and is advertised to be accurate to within .1 lb, which is well within my requirement for comparison testing. Had all of them tested within a pound or two, I would have built a tool to test them as installed, but at this point it didn’t seem necessary since there was so much difference seen in my simple test.
ReplyDeleteAs far as Plymouth v. Dodge questions, I’m not positive that the two strongest springs I tested are from a Plymouth. I ordered them from ebay soon after I bought the Belvedere, as one was missing and I knew I’d need replacements. I know the rusty one that read low was the one left on my car, so I have no reason to believe it wasn’t the original. I really don’t want to pull the ones from my Fury until it’s time to strip everything, and since that hood already sags I’m certain they won’t be anything I want to use. Any testing of them would be curiosity only.
If you want me to test your springs, I'd be glad to test them the same way, if you think it's worth doing, but since my test was only for comparison, I won't swear to accuracy of the readings. That would require a much better test setup.