Extending bonnet length

I finished mocking up the bonnet and trial fitted it yesterday. My son and I spent all morning with a laser level, tape measure, spirut level etc making sure that the car was level and the bonnet was centered and levelled to the car. It fit better than expected except for one little hitch. Even with all the shims that control forward and aft movement there is still a 1/2 inch gap between the back edge and the scuttle so I am faced with welding on an extension. It appears to have been trimmed in the past as the edge is somewhat ragged.

As the rear support brace has to be removed to repair rust holes and for rebonding my plan was to put the join where it well be covered by the support on the bottom. That way the weld does not have to be dressed down except for on the top surface. I am looking for any advice or tips from anyone who has had to add material to the back of a bonnet or really to any other very long, very visible area.

Panel alignment pins, careful fitting, low heat welding, hours of fettling.

That’s no fun. I am looking for magic here.

Have you tried

these? CJ claims they will bring your bonnet up to 1/2" closer to the firewall - might be worth a try. No affiliation.

Good luck.
Craig

Hello Geoff,
Are all the air ducts and baffles in place and secured to the angle strips that should be bonded to the under surface of the bonnet? You will find that the whole bonnet centre and wing assembly relaxes forwards without these supports. The whole bonnet can be pushed to the rear as the lower valance inner bracing flexes.

An S1 2+2 that we have currently in work had a rear bonnet edge gap slightly larger than yours and ultimately had a small amount removed from the raw edge to get the shut line perfect with all the ducting in place and bonded.

Regards,

Bill

I fitted these on my car. Had about a 3/8" gap when I bought it with lots of shims. Now at 3/16" with less shims.

Take a look here

http://www.monocoque-metalworks.com/main/2014/10/adding-metal-to-the-rear-edge-of-an-e-type-bonnet/

John North
S2 Coupe
S1 Roadster

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First off, many of the replies seem sensible - especially the special hinge in your case (I think those only move it in toward the scuttle, not OUT).
I used a method that seemed to work very well for me. Since we have a doubled edge from the supports the run along the rear edge of the fenders and the center bonnet section, you can use a double thick piece of sheet metal folded over with the inner edge lined up with the support. This isn’t very noticed and also gives a rounded edge of double thickness as an edge. This is hard to explain, but I have a picture of a section I put on the edge of a fender:


Now you have 2 options - you can plug weld this from the back side by Whitney punching plug weld holes or you can use panel adhesive if you don’t want heat all over the place (like you have bondo or paint everywhere). I used panel adhesive. There are various types, some are more resistant to temp change, “ghosting”, etc. You fill the outside edge rather than weld it. Now you have a sharp line to fill, which can leave a visible line if the filler cracks, etc. Lead would be best but if you glued it, heat is out. I beveled the edge a bit and you really need to get the filler right and pressed in any gaps with no voids - even tiny ones. If the gap is tapered or arced making the piece is real hard, you need to allow complex bend allowance. The metal must take a 180 degree bend, so must be soft-ish.

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You might want to consider a flange tool so that you don’t have to butt weld. Also, a stitch welder would help. Check out youtube for quarter panel replacement.

https://search.eastwood.com/search?lbc=eastwood&method=and&p=Q&ts=custom&uid=903498845&w=flanger&af=tab:video

Thank you for all the excellent suggestions. My bonnet is assembled with all the pieces bolted and screwed together but the frlanges are not bonded yet. I think my plan of attack is to get under the car and slightly loosen all fasteners and then attach a tiedown strap to the rear support beam and gently try to pull the bonnet back. If that does not give me sufficient movement then the Classic Jaguar hinge is probably the best solution. My only reservation is that my car has the covered headlights so the clearance from the headlamp buckets is less than the later cars. Does shifting the front crossmember back 1/2 inch potentially run the risk of clearance issues?

It definitely can result in clearance issues, not only with the buckets on a hard bounce but even the baffle itself.

Before you go any extreme lengths by adding metal to the bonnet edge it’s maybe worth checking a couple of measurements first in case something else is wrong with the bodywork such as incorrectly installed sill panels etc.

The length from the bottom rear corner of the fender wheel arch to the rear edge of the fender should be between 19-1/4" and 19-3/8". According to what you showed, yours would be about 1/2" shorter. If this is the case, I guess the only solution is to go ahead with the extension but at least check it first.

Getting a good bonnet fit is probably one of the most frustrating jobs on an E-type, I think.

I had the same problem with my bonnet. Since I am not an accomplished welder, I paid a local shop $700 (in about '86) $700 to hammer-weld a 1" strip along the entire rear edge of the bonnet, then took it home and trimmed it to fit. Came out great.

Regards,
Ray L.

Ding DingDing Ding. It looks like Bill has given me the answer. Thank you Bill. I loosened up everything and then put a tiedown from the bonnet to the trunk panel. A bit of gentle pulling closed up the gap to 3/16 at the narrowest place. I feel a little foolish for not realizing that a floppy bonnet would move lengthwise as well as in all other directions. It would have pulled back more but I think that is good enough for now. I now will pull the whole thing apart for epoxy primer and then get the panels bonded on when I remount it. The lower wings at the back still need replacing and the rear supports need repair and rebonding/ welding but that will wait untill the final shape of the rest is set. Once again thank you to everyone for their suggestions. It amazes me how almost any problem gets solved on this forum. ( And no one calls anyone else a moron unlike lots of other forums)

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Clive.
Sills are in correctly as they are new MM units and are installed lined up with the new Robey floors. They have 19 3/8 stickout at the front which is within spec. Unfortunately my lower rear wings have been replaced in the past bu a cowboy with a big hammer and amig welder. They have to be removed and new patch panels fitted once the bonnet position is finalized. Thanks for the heads up though. I always appreciate a reminder.

Ray
Probably the safest solution but it looks like I may get away without adding metal. Bill supplied me with what looks like a viable work around. With that plus paint thickness and possibly a slight skim of the hinge I think I will be ok. Just for info purposes (hopefuly) what was your trimming technique?

It was a long time ago, but I believe I fitted the bonnet, getting it all aligned correctly, but too far forward. Then drew a rough line that would leave it about 1/4" too long, and cut off the excess. Then used a caliper to scribe a line, exactly parallel to the front edge of the cowl. Trimmed to that line, leaving a tiny bit of extra metal. Finished using a file to get it perfect. Took a few hours to do the whole thing.

Regards,
Ray L.

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Geoff,
I trimmed my wings with a regular hacksaw followed with a long flat file. I had bought new wings from Jaguar, way back and they came maybe 1/2" longer than I needed.

Hows does the fit of the wheel arch to the rocker look?

Can’t tell because the lower rear of the wing is not original. One of the patches is too short and the other is too long when measured from the front of the wheel arch. Hoping I get really lucky and my patch panels fot right in the middle. It could happen.