Bonnet metal hoop, when was it introduced?

[nebogipfel]

Hello all,

Just wondering if anyone knows when the tubular hoop was fitted to the underside of the bonnet? We were having a conversation the other day and the topic came up so I wondered if anyone knows roughly when Lotus fitted it (chassis number/series) and if it continued to the end of Elan production?

I'm referring specifically to the tube which starts roughly 6" from the trailing edge of the bonnet and curves around the front perimeter and to which the spring hook is attached.

Thanks

[garyeanderson]

Greg posted some info on his sprint bonnet here
elan-f14/bonnet-spring-hook-t23362.html

I posted a photo of 36/5520 bonnet there too, I can get some more I am sure but my original 70 coupe bonnet is now gone, left with 45/8221 and those photos are now gone. 45/7334 is an S3 SE has the same as 36/5520

[nebogipfel]

Greg posted some info on his sprint bonnet here
elan-f14/bonnet-spring-hook-t23362.html

I posted a photo of 36/5520 bonnet there too, I can get some more I am sure but my original 70 coupe bonnet is now gone, left with 45/8221 and those photos are now gone. 45/7334 is an S3 SE has the same as 36/5520

45-7334 front.JPG

Thanks Gary, I have seen the method used on your picture of 36/5520 but assumed the tubular reinforcement was the improved and final method used?

It appears that at least some current replacement bonnets are manufactured without the metalwork and are intended to have the flat plate arrangement pictured on 36/5520 retro fitted.

The hoop is clearly the strongest and best solution and I was wondering when it was introduced both as a matter of interest to me and for general historic/originality info' for members of the forum

[garyeanderson]

I don't remember it being on the bonnet from 7004090078E but its been gone for almost 9 years. That said it could have been but I think I would have noticed it being different, it was on and off a lot it seems. I hadn't seen the tube type until Greg posted the question in the link, I am not into those new Elans, I like the older models you know.

Gary

[nebogipfel]

I don't remember it being on the bonnet from 7004090078E but its been gone for almost 9 years. That said it could have been but I think I would have noticed it being different, it was on and off a lot it seems. I hadn't seen the tube type until Greg posted the question in the link, I am not into those new Elans, I like the older models you know.

Gary

Yes, you and I are of a similar vintage Gary and the old brain cells become unreliable

I'm a fan of the new fangled Type 36/45 and to be honest I thought they all had hoop type bonnets.

I assume there must have been a point in production when it was introduced to overcome a problem with the earlier type and it would be interesting to know when.

Perhaps this is a question for Robinshaw and Ross? or indeed our own Tim Wilkes?

[elansprint71]

Is the hoop metal? I always thought that it was a piece of rope glassed into give the strength. I've seen cardboard tube used on race-car applications to give support to flimsy glass panels.

Both my cars have it- 69 and 72.

[nebogipfel]

Is the hoop metal? I always thought that it was a piece of rope glassed into give the strength. I've seen cardboard tube used on race-car applications to give support to flimsy glass panels.

Both my cars have it- 69 and 72.

I know what you mean about glassing over something to create a stiffener.

I've always assumed it's tube Pete and that the bonnet spring hook is welded to it?

Some clever person on here must know ...

[garyeanderson]

Is the hoop metal? I always thought that it was a piece of rope glassed into give the strength. I've seen cardboard tube used on race-car applications to give support to flimsy glass panels.

Both my cars have it- 69 and 72.

Have what Pete? a tube, a plate, or paper tube?

Look at the link
elan-f14/bonnet-spring-hook-t23362.html

Gary

[nebogipfel]

Is the hoop metal? I always thought that it was a piece of rope glassed into give the strength. I've seen cardboard tube used on race-car applications to give support to flimsy glass panels.

Both my cars have it- 69 and 72.

Have what Pete? a tube, a plate, or paper tube?

Look at the link
elan-f14/bonnet-spring-hook-t23362.html

Gary

Thanks Gary, Greg's pic' in the link above clearly shows the metal tube

So now I'm back to my original question/s

1. When was it introduced?

2. Did it continue to the end of Sprint production?

PS FWIW My '69 car has it, but I can't be certain the bonnet is the original.

[elansprint71]

Is the hoop metal? I always thought that it was a piece of rope glassed into give the strength. I've seen cardboard tube used on race-car applications to give support to flimsy glass panels.

Both my cars have it- 69 and 72.

Have what Pete? a tube, a plate, or paper tube?

Look at the link
elan-f14/bonnet-spring-hook-t23362.html

Gary

Thanks Gary, Greg's pic' in the link above clearly shows the metal tube

So now I'm back to my original question/s

1. When was it introduced?

2. Did it continue to the end of Sprint production?

PS FWIW My '69 car has it, but I can't be certain the bonnet is the original.

No use in trying cross-ocean irony on this forum, Mr Time-traveller; it goes no further West than Rockall.

In answer to your subsequent two questions:

1. Don't know.

2. Don't know.

No idea why the "plate" red-kipper was dragged in, seems to me that someone is desperate to answer questions which were not asked, for reasons I cannot fathom.

[elanfan1]

My January 73 Sprint has the metal tube so that might answer one question.

A previous Sprint (1971 not that it matters) had a replacement bonnet that just had a plate at the front to which the hook was welded. This eventually deformed the front edge - I'm guessing a mixture of heat from the radiator and the tension of the spring pulled the front edge down and i had to replace it.

[nebogipfel]

My January 73 Sprint has the metal tube so that might answer one question.

A previous Sprint (1971 not that it matters) had a replacement bonnet that just had a plate at the front to which the hook was welded. This eventually deformed the front edge - I'm guessing a mixture of heat from the radiator and the tension of the spring pulled the front edge down and i had to replace it.

Thanks for that info'

As I expected a latish Sprint had the improved arrangement.

I have always thought that the later design was incorporated for just the problem you describe on your replacement bonnet.

Any other offers please ..........Tim W ....where's our historian?

[Elan45]

I use a 1 inch diameter (25mm) keyring threaded onto the bonnet and then attach the big spring to the keyring. Essentially, this weakens the spring force down on the leading edge of the bonnet. There is enough force to assist in lifting the bonnet when the releases are pulled, but not so much that it causes distortion from the baking sun or engine temps.

Roger

[nebogipfel]

I use a 1 inch diameter (25mm) keyring threaded onto the bonnet and then attach the big spring to the keyring. Essentially, this weakens the spring force down on the leading edge of the bonnet. There is enough force to assist in lifting the bonnet when the releases are pulled, but not so much that it causes distortion from the baking sun or engine temps.

Roger

That's interesting Roger but doesn't answer the question

I have it from a pretty reliable source that later S4's and all Sprints have the improved bonnet as standard. ...... So unless someone wishes to disagree?

[bcmc33]

FWIW, the hoop on my car is steel - it's magnetic.