TR2/3/3A Hood / bonnet plinths

[LionelJrudd]

My car is pre 60k and does not have plinths for the hinges on the boot or hood. I have a post 60k bonnet I want to use and will therefore remove the raised plinths on the hood so it matches the body tub.
I notice the hood has a strengthening piece under the plinth that sits in the plinth recess in the hood.

Could someone advise me whether the pre 60k hoods had a similar strengthening piece where the mounting studs go through the hood. If it does have the reinforcing pieces, is the strut that goes accross the back of the hood recessed to accommodate the reinforcing piece?
A photo would be nice.
Regards, Lionel

 

[CJD]

To the best of my memory...the rear strut, or reinforcement band that runs across at the rear of the bonnet is the hinge reinforcement. It has slotted holes for the hinges, but no other brackets or such. I’ll double check to be sure...

Edit...

Nope, my memory fails! Here are pics. There is a reinforcement, but a recess is not required. The rear band is held off from the bonnet by horse hair, except at the location of the hinges. At the hinges the band stretches down to the reinforcements, sort of the opposite of a recess.

https://i.imgur.com/ZNcLEnF.jpg

 

[CJD]

Doggone if imgur isn’t screwing with their service. I’ll have to figure out how to post again.

Edit...Yep. I can no longer use the phone to post. Only on a real computer. Here are the pics...

 

[Frank Canale]

Hi Lionel, I compared my bonnet to the pre 60K bonnet that came with my car and noticed the pre 60K bonnet has a rivet that attaches the reinforcing piece to the bonnet. There is one rivet on each side. the picture is the right side facing the bonnet. Hope this helps. I thought about converting the pre 60K bonnet but looks like less work fixing the original bonnet. My car has stalled, adding on to my shop to make room to work. Hope to be back at it this fall.

 

[LionelJrudd]

Thanks for the help John and Frank. I have removed the stiffening pieces from the bonnet and attached photos of the bolt holes and reinforcement. From your photos and mine it seems the post 60k has an additional strengthening piece that fits up into the plinth. I think I only need to remove the additional piece from each side and use the stiffening piece as it is.
I have already worked the plinth back into the bonnet so they are now flat as per the pre 60k bonnets. Without the extra strengthening piece, it will sit flush with the bonnet shell.
Let me know if you disagree.

As an aside, the front stiffening piece was spot welded in several locations along the leading edge to the bonnet. Is this your experience?

 

[LionelJrudd]

Frank, John, any idea when those rivets were used? John, did your TR2 have them? Seems to me they would have the potential to force the bonnet skin closer to the stiffener and potentially distort the shape.

Frank, I know about delays. Body work on my car stalled for a variety of reasons including simply needing a break from wielding the hammers. Even so, I have continued getting the engine organised and suspension work done... not that any of it is complete. So many small things to do that don't make headlines in your report.

 

[Frank Canale]

My extra pre 60 K bonnet onle has a note on it, "TR3 56 - 59 so I don't know about the change. My original bonnet has spot welds only at the far edge where the stiffener fits into the channel that meets the wing. Thank you for the encouragement like you say research continuing and minor organizing, I know it all has to get done so any work helps the cause.

 

[CJD]

The rivets were used on the bonnets with the sharp rear edge. Since the bonnet skin essentially “floats” separate from the rear stiffener, they are needed to keep the skin aligned in the left/right direction. The stiffener has a pad bent upward where the rivet goes, to prevent the bonnet skin from puckering downward. It is pretty Mickey Mouse!

The rivets ended when the factory started rolling the rear edge of the bonnet skin over to give it some rigidity. The front brace is held like a door skin. The bonnet edge bends 180 degrees to capture it, and then they spot welded.

 

[Frank Canale]

according to Bill Piggott " Original Triumph TR" book at the end of the chapter he list the production changes. TS 22530 October 57 Rivets deleted from rear edge of bonnet.

TS60001 October 59 new bodyshell tooling, raised platforms for the bonnet and boot hinges.

 

[LionelJrudd]

How thick am I? Looking back I see I forgot to attach the photos!
Here they are for completeness.


Thanks for the follow up Frank.

 

[sp53]

I would guess that little re-enforcement piece would have set up in the void and now you would not want it. I am curious how did you get the raised part flat—heat and beat?—Moreover, are the hoods the post60k and pre60K hoods the same size--- width, length, and height. I read something years ago about there being 3 or 4 actual hood styles and maybe sizes also. But I am sure you will make it work fine—keep posting Lionel- I have no entertainment and this helps. I did have some fun this summer in Cambodia playing poker for 3 weeks and seeing old friends, but I spent all my money, but what the heck have some fun in life. Perhaps I should have popped down under to see if you really exist and are not some Artificial Intelligence putting a car together as a secret computer project using the forum language as a scanning tool for assembly.
steve

 

[LionelJrudd]

Steve, just back from a month in Indonesia. We could have met halfway in Thailand.
Re the size, I think they are basically the same overall size. Really only minor changes such as number of rear slots and then the introduction of the raised plinths.
The majority of bonnets have the lip at the rear edge. I folded that out a little so it was at right angles to the panel and then just cold worked the plinth back into the panel with hammer and dolly. The small amount of shrinkage required did not present a problem.
The reinforcement piece is held on with two spot welds so was easily removed leaving the structure in John's photo above. Have to rebuild the front edge and the rear edges where the stiffening braces go but will report back on that in my original thread when I complete it.

 

[Jim_Stevens]

I had the opposite to deal with... the rear half of my pre-60k car was from a post-60k repair. So the plinths had to come off and we had to put back in the sloping rear floor. The car was a real mess!
.