Bonnet hinge modification

[cass3958]

I want to alter the hinge in such a way that it still looks and works like the original but by removing a nut and bolt you can then swing the bonnet up vertically and fix it in place allowing you to get to the back of the engine compartment without either banging your head on the bonnet, having to slide under the bonnet whilst lying across the wing or having to remove it completely which is what I normally end up doing. As I said I have ideas but no time at the moment.

[cass3958]

Today I learnt two things.

1. Somethings are designed they way they are for a reason.
2. You only find out about number one if you try and change the design.

Something I have been meaning to do for a long time but now I am incarcerated in the house for the next three months because of the Corona Virus and have time on my hands I thought I would have a go at the bonnet hinges. One of the design faults of the Mk2 and S type Jaguar is that the bonnet does not open fully going up no more than 45 degrees. This means if you want to clean or work on something at the back of the engine bay the bonnet does not lift high enough and you end up either doing the limbo under it to clean or you have to remove the whole bonnet for the bigger jobs. Even removing the battery or putting jump leads on the terminals is a pain the way the bonnet opens.
So I got out a spare set of hinges I had, sat down and gave them a good look. The bonnet is stopped from rising higher than 45 degrees because of two things on the hinge.

First there is a riveted block which one of the hinge arms hits as the bonnet raises.
Secondly one of the lower arm swivels hits the bracket that bolts to the wing.

Hinge stoppers.jpg (5.16 MiB) Viewed 2639 times

Stopper rivet removed.JPG (2.19 MiB) Viewed 2639 times

Bottom Bracket Stopper.JPG (2.6 MiB) Viewed 2639 times

OK so what happens if you remove the rivet and move it back ¼ of an inch.

New stopper bolt in place.JPG (465.18 KiB) Viewed 2639 times

Then cut out an arc from the lower swivel arm?

Bottom Bracket altered.JPG (2.09 MiB) Viewed 2639 times

Hey I can now get the hinge to rotate from 45 degrees to 75 degrees and have not radically altered the look of the original hinge.

IMG_8642.JPG (2.39 MiB) Viewed 2639 times

Result I thought as you can see from this last photo how much more upright the bonnet plate is compared with the original unaltered hinge behind.

Removed the bonnet and the old hinges from my car. Left hand side is a bit of a fiddle as the heater box gets in the way but the three bolts came out. Fitted the new adapted hinges, again a fiddle to get the left side bolts in but all done. Refitted the bonnet to the hinges and raised it gingerly to about 50 degrees and then found that the way the hinge works is such that the back of the bonnet lowers in to the engine bay as you raise the front. As the back of the bonnet drops it hits the top of the heater box and that my friends is why the bonnet has those two pieces to stop it going beyond 45 degrees.

Bonnet resting on heater box.JPG (1.69 MiB) Viewed 2639 times

Car has been put back to normal and I have gone back to the drawing board with my new found experience.

[DevilDog]

What a job and tremendous effort.

Keep charging,

[Glyn Ruck]

Rob, Isn't there a completely redesigned hinge shown somewhere on this forum to raise the bonnet to vertical? I know I've seen it somewhere. Either here or Jaguarforums.

You are a brave man. Every time I've removed my bonnet it has take at least 6 hours to get it aligned perfectly again when refitting.

[cass3958]

Glyn on page one of this topic there are pictures of a hinge designed, made and fitted to an S Type which raises the bonnet to a vertical position but it does not bear any resemblance to the original design. I could replicate that but thought as I had a spare set of hinges I would mess about with them and see what I could produce. I would like to keep the original hinge but somehow adapt it to open fuller. It is still a work in progress so watch this space. During the Corona Virus lockdown I have lots of time to think about it.

[Glyn Ruck]

Sorry Rob ~ none so blind as myself for not paging back. I knew I'd seen it somewhere.

[NigelW]

It might be of interest to try to design a hinge modification something similar to the boot hinge mod that was designed by a member of the XJ forum from California that raised the boot lid position and moved the lid away from the window.

I recently fitted a kit he sent over to me and has made a big difference in so much as I don't hit my head every time I open it and makes working on the fuel supply system much easier as it is all fitted beneath the boot floor. The kit has an added bonus of a pair of gas struts to support the original hinges that were getting weak.

[cass3958]

I like that one Nigel and had thought of just adding an extra section to lift the bonnet higher whilst leaving the original hinge in place. One of the problems we have with the Mk2/S type bonnet is that as the hinge lifts the bonnet up it also slides it forward so the back of the bonnet still covers items such as the battery and starter solenoid even if I can get it vertical. Needs a bit more thinking me thinks.
At least with this spare set of hinges I can bastardise them as much as I want to the point of ruin if need be. I also have a set of BMW gas strut hinges which I am going to play with but I did want to keep the original hinges or at least the original look with an adaptation.
Watch this space.

[Glyn Ruck]

The bonnet opening is less than ideal for access. I connect my maintenance charger via the gap between the rear of the bonnet & the scuttle. I have just bought a set of leads to plug it into the underbonnet auxiliary socket.

[cass3958]

I have a remote connector on my battery charger which is basically two wires which connect to the terminals and a plastic plug which can reach out onto the wing but can be stored down the side of the battery when not in use. The battery charger has the same connection so I can just plug the two together to trickle charge every now and then. I have the same set up on the motorbike as it saves me having to strip the bike down to get to the battery terminals. https://www.ebay.co.uk/itm/12-24V-Motor ... SwcOBduUxp