New Bonnets

[andrewh]

There has probably been a lot of chat on this subject before, I have done a search but didnt find the information I would like, so here goes.

Many years ago, I heard that the Heritage Bonnets made and supplied by Jaguar were made on old tooling and were not that accurate in shape. I realise that a bonnet needs a lot of fitting to each car, but thats not really what I mean. Are the creases and swages generally correct and are all the holes in the right places with the correct tappings etc? Just general obsevations would be appreciated. Thanks

[christopher storey]

This question is not easy to answer. My heritage bonnet for my S1FHC, supplied about 2.5 years ago , was very accurate in terms of shape, but I was annoyed to find that the fixings for the headlight glass surrounds were not in the correct place, and the bodyshop had to spend a fair amount of time correcting this . However, wherever you get the bonnet from , fitting problems of this sort are likely to arise . If your current bonnet is repairable - and many are if the top centre section is still OK - you are better off having it dismantled and reassembled with new relevant parts . The bits which tend to go first are the front underpan , and if the car has been used in poor conditions , the upper parts of the wings and the centre section flange to the wing . You will get really good advice on this if you speak with Andy Rayner at Hutsons , who make many of the bonnet parts now , 01274 669052 , and who if you sent your bonnet to him, would give you straight advice as to whether a first class job could be made of repair or not

[andrewh]

thats interesting, I had heard that its best to try to use the original bonnet if possible. It was that comment that prompted the questoin. Why? I am sure my centre section would go agian, but not sure why one would bother if you then fit new replacement parts elsewhere. One sort of thinks it must be better to get a whole new bonnet. What I am trying to understand is why a professionsal restorer would value keeping the centre section. There must be some issues with the replacements!?

[christopher storey]

The centre section is the most difficult to reproduce accurately because of the size of press tool / die required . Even the Abbey panels ones are said to have varied over the years because the tool/die were rumoured to have been made of concrete which wears of course ! I believe that Hutsons have now found a workshop in Poland with tool capacity to make these centre sections accurately . The reason why the centre section is crucial is, I believe , because although it is the most visible part of the assembly it is also the least stiff part and thus its initial accuracy is of primary importance

[Dave K]

As christopher says even when Abbey panels made the bonnets (some of my mates served their time at Abbey) there were fitting issues.
On my bonnet which is an original one wing is slightly longer than the other at the side where it meets the sill.
They tools were originally made from concrete mainly because Jaguar never thought they would have to make many of the cars.

Dave

[PeterCrespin]

The concrete tool thing is true, but only in the very, very, beginning. I'm sure that by about the 500-1000th they were made on proper press tooling. I think it gives a number in Porter's big book?

Of course there are quite a few bonnets that were subsequently pressed out of shape again by concrete, but we won't go there (and they shouldn't have either

As for bonnets from Jaguar not having the holes in the right place for the headlight trims, is it not possible that by 40 years later the headlight trims are the incorrectly-made item, not the bonnet? If you are trying with original trims then obviously not, but I still have my original 2+2 1966 bonnet and the repro headlight rings I have don't fit.

I bet a small part like that is much easier to mess up and make without due care, than a big bonnet...

[MarkE]

Andrew, I?ve noticed differences between the bonnets on my two cars, both original, and the ?new? bonnets available.

For the S1, the main difference appears to be around the louvers and the nose. The louvers don?t sit up on the new bonnet as they do on the original, and the double curvature of the nose seems to be flatter on the new. When my Coupe was being painted, another S1 came in for a bonnet, and the bodywork guy pointed out these differences, which were quite striking when parked next to each other. He also pointed out the curves on the top of each wing (when looking down the bonnet, were a bit flatter on the new bonnet, but I must confess that I couldn?t see a huge difference here.

There?s a much more noticeable difference with the S3 bonnet, which has little squared-off flairs on each wheel arch. These are quite sharp and well defined on the original bonnet, and on the new bonnet it?s more rounded and dull?looks like it?s full of filler! The S3 also has the same problems as the S1 bonnet.

I have little doubt that something has changed between making the original and the current bonnets. If yours needs work, try and get it repaired rather than replaced.

The other panels are worse, by the way!

[christopher storey]

is it not possible that by 40 years later the headlight trims are the incorrectly-made item, not the bonnet? If you are trying with original trims then obviously not, but I still have my original 2+2 1966 bonnet and the repro headlight rings I have don't fit.

I bet a small part like that is much easier to mess up and make without due care, than a big bonnet...

Peter : I cannot be sure that my chromes were original, because I have only had the car 18 years, but all the indications were that they were original . It was only when we tried both my originals ( which didn't fit) and a pair of definite originals ( which didn't fit) and a pair of repro ones, ( which were much closer to fitting) that it became clear that the bonnet was at fault

[andrewh]

As always guys, this is great colour. Although I have had several E Types I have not restored one, and I am finding this forum superb for getting me up the curve on information. I tend to think well in front of myself when doing a restoration and want to get as much information as possible as it helps with the whole understanding and project management. The bonnet issue is an interesting one, and one I am going to look into in more detail. I have spoken with the chap who I am considering asking to restore the body, and he has told me today, that as said here, if we can at least keep the centre section it would be preferable. This may be a reference to the louvres and or the curvature of the bonnet itself. Certainly going to try to do that if I can. Thank you for all your input.

[ChrisC]

I have the original light trims but my bonnet too had the holes in the wrong places. I thought I had a rogue bonnet so in some ways it's nice to know there are more like it out there. I welded up the holes and had new cage nuts put in the right place.

[PeterCrespin]

It was only when we tried both my originals ( which didn't fit) and a pair of definite originals ( which didn't fit) and a pair of repro ones, ( which were much closer to fitting) that it became clear that the bonnet was at fault

Case closed.

Not good eh? I suppose it's because the new bonnets are so cheap, NOT.

[Heuer]

From our 'Factoids' thread:

29. Because of the low planned production run Jaguar did not want to spend money on body tooling. The first tools were made by hand forming 16 gauge steel panels, putting them in wet sand and pouring concrete on top. Panels were then formed by stretch pressing over these concrete reinforced steel moulds. They wore out quickly and one of the first casualties was the definition of the bonnet power bulge ? originally a very sharp crease at its perimeter, now usually a gentle curve.
30. Later body tools were made of zinc based Kirksite, more suitable for mass production, but not ideal. Other parts used mechanical press or a rubber die press.