hood straightening

[shelbymann1970]

Interesting. I always thought this might be the case since the hood doesn't fly open when you release the latch. It does pop so maybe there is some load or pressure?


  Take the weight of the hood. The springs all the way in the close position may not open the hood all the way but what cars do? They are still putting pressure on the hood at the back so the weight beyond the hinges is fighting the short area where the springs have pressure which leads to hoods bowing. How do I know this is true? Well on my old black 68 Shelby my hood had a slight bow until I removed my springs. Ditto for my 70 over the last 35 years. Try it out sometime and see.  Gary

[Rodster-500]

Interesting. I always thought this might be the case since the hood doesn't fly open when you release the latch. It does pop so maybe there is some load or pressure?


  Take the weight of the hood. The springs all the way in the close position may not open the hood all the way but what cars do? They are still putting pressure on the hood at the back so the weight beyond the hinges is fighting the short area where the springs have pressure which leads to hoods bowing. How do I know this is true? Well on my old black 68 Shelby my hood had a slight bow until I removed my springs. Ditto for my 70 over the last 35 years. Try it out sometime and see.  Gary

Hotrod Hillbilly claims there is no pressure on the back of the hood when the hinges are closed and in the rest position. Kind of like something going over center. I can imagine the hood hinges designed to operate that way but I don't have any cars with the hood off for a real world test.  Can anyone confirm this?

I wasn't going to take a chance so I removed the springs on my 500. I have springs on my 350 but leave the hood open. Is that better or worse?

I wonder if it's hood dependent too?  Hard to believe all hoods are built exactly alike and some are 'weaker' than others?

[shelbydoug]

Interesting. I always thought this might be the case since the hood doesn't fly open when you release the latch. It does pop so maybe there is some load or pressure?


  Take the weight of the hood. The springs all the way in the close position may not open the hood all the way but what cars do? They are still putting pressure on the hood at the back so the weight beyond the hinges is fighting the short area where the springs have pressure which leads to hoods bowing. How do I know this is true? Well on my old black 68 Shelby my hood had a slight bow until I removed my springs. Ditto for my 70 over the last 35 years. Try it out sometime and see.  Gary

Hotrod Hillbilly claims there is no pressure on the back of the hood when the hinges are closed and in the rest position. Kind of like something going over center. I can imagine the hood hinges designed to operate that way but I don't have any cars with the hood off for a real world test.  Can anyone confirm this?

I wasn't going to take a chance so I removed the springs on my 500. I have springs on my 350 but leave the hood open. Is that better or worse?

I wonder if it's hood dependent too?  Hard to believe all hoods are built exactly alike and some are 'weaker' than others?

It's the nature of the materials used. The resin is flexable much like wood would be and can be bent.

The original hinge design is for steel hoods.

This is really an issue of mixing mediums. A fiberglass hood is really a "race car derivative". That has a few implications.

One is the issue of longevity. The other is lack of intended precision.

While Smith is somewhat of a cutting edge manufacturer with molded fiberglass reinforced resins, the point in time had approached solving issues with precision fiberglass "stampings" but not necessarily rigidity. Certainly not for a product that would have intentions to last over 50 years?

I'm not sure how you would reinforce the fiberglass to resist these "warpings" but the fact that you can bend it back to where it was supposed to be is a pretty good indication of the flexible nature of the material. It's too flexible.

The use in the Shelby hoods is probably crossing the line into how to use stressed fiberglass panels in a structural application. Something that I never heard of when back in school.

I suppose the text was still waiting to be developed at that point?

Although Smith had built many fiberglass Corvette hoods by then, the hood hinge approach by GM is different.

As I remember the 68s and 69s, the Shelby hoods new that I saw all fit very well.

The '67s apparently were just made twisted to begin with? I think that bending them with these methods like "sand bags" is close to the solution "restorers" are using to get some sort of fit on the front that doesn't make the car look like it was hit hard on the drivers side

[2112]

Do you leave the chain hanging on the hinge while driving?

(Second picture prompted the question)

Yes, I leave chains hanging, the heater hoses help keep them from scraping everything up.
The chains were originally going to be temporary until I came up with something nicer (plastic coated cables maybe?), but we all know how that goes!

I think it is a great solution.

Especially after seeing your hood.

[mikeh]

Thanks 2112.
And R.I.P. Neil Peart

[1969shelbygt350]

I removed the springs on both sides and now the hood is straight with closing! NOW WHAT. Should I use low tension springs or as they are for now?

Thx
Paul

[Bob Gaines]

I removed the springs on both sides and now the hood is straight with closing! NOW WHAT. Should I use low tension springs or as they are for now?

Thx
Paul

The low tension springs may not hold the hood up . It will on some but others not.  If it did I would be careful leaving it open unattended. A slight breeze may cause it to come crashing down on someone's head.  I used to re attach the factory springs when having my hood open. I got so I could do ether side in leas then a minute . I repurposed a spare tire long hold down hook and used it to lever the springs on and off using my shoulder to hold the hood while doing it.

[1969shelbygt350]

This is a picture after I removed springs and hood latch closed