I have a 1974 OTS, the car was damaged in shipment, it was in a container, which was dropped by the shipping company, resulting in it rolling back and forth for an unknown number of miles.
This primarily damaged the nose of the bonnet quite badly.
Prior to this the car was in perfect condition, it only has 17000 miles from new and has always been in California.
The bonnet was removed, disassembled, stripped, and all pieces E-Coated.
It was then panel beaten back to shape (center section and lower valance).
It is now reassembled with all the original parts, but not yet bonded.
On offering it up to the car it is way out of alignment, which I expected, but this isn't even close.
Before I make any adjustments I thought I should check that the Engine frame/monocoque relationship is correct.
I am unable to find any basic measurements/dimensions with which to perform the check.
Does anyone know where I might find this information?
Any help greatly appreciated, thank you all!
Tony R
basic dimensions for front frame alignment
#2 Re: basic dimensions for front frame alignment
Hello Tony,
You will find the dimensions you require in the V12 Series 3 E Type, Repair Operation Manual at the start of the Body Section.
You have the right approach in checking that the frame members are in the correct location. It could also be that the support section of the lower valance, where the bonnet hinges attach, could be damaged, resulting in poor bonnet alignment.
You haven't mention what alignment issues you have. Is the shut line gap between the rear edge of the bonnet and the cowl way too big, or is the edge of the bonnet overlapping. For the frames to be damaged, the gap there would be nonexistent, or the bonnet overlapping the cowl. However, if the air ducts and other support features on the underside of the bonnet are not jet secured in place by bonding etc. its typical for the unsupported bonnet to relax forward, resulting in a large gap between Bonnet and Cowl.
With cars that have had a well fitting bonnet and it has been dismantled and reassembled, we typically use light ratchet straps secured to the rear brace of the bonnet, at the centre of the power bulge, with the bonnet mounted on the car, to pull it back to good alignment before bonding the support components.
If the bonnet is too far back, don't get sucked into putting a extra large stack of hinge to bonnet spacers in place. The maximum stack thickness is circa 11mm. Sure, you can loosen the quite long bolts that are correct for there and more spacers put in place, but when the bolts start to tighten on the stack of spacers, the mechanical advantage obtained by the Thread Helix, will simply distort the area of the lower valance panel where the hinges attach. If it looks like you have to use more than 11mm of spacers, look for the reason and correct it.
Regards,
Bill
You will find the dimensions you require in the V12 Series 3 E Type, Repair Operation Manual at the start of the Body Section.
You have the right approach in checking that the frame members are in the correct location. It could also be that the support section of the lower valance, where the bonnet hinges attach, could be damaged, resulting in poor bonnet alignment.
You haven't mention what alignment issues you have. Is the shut line gap between the rear edge of the bonnet and the cowl way too big, or is the edge of the bonnet overlapping. For the frames to be damaged, the gap there would be nonexistent, or the bonnet overlapping the cowl. However, if the air ducts and other support features on the underside of the bonnet are not jet secured in place by bonding etc. its typical for the unsupported bonnet to relax forward, resulting in a large gap between Bonnet and Cowl.
With cars that have had a well fitting bonnet and it has been dismantled and reassembled, we typically use light ratchet straps secured to the rear brace of the bonnet, at the centre of the power bulge, with the bonnet mounted on the car, to pull it back to good alignment before bonding the support components.
If the bonnet is too far back, don't get sucked into putting a extra large stack of hinge to bonnet spacers in place. The maximum stack thickness is circa 11mm. Sure, you can loosen the quite long bolts that are correct for there and more spacers put in place, but when the bolts start to tighten on the stack of spacers, the mechanical advantage obtained by the Thread Helix, will simply distort the area of the lower valance panel where the hinges attach. If it looks like you have to use more than 11mm of spacers, look for the reason and correct it.
Regards,
Bill
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#3 Re: basic dimensions for front frame alignment
Hi Bill,
firstly, thank you so much for responding, really appreciate it.
Found the dimensions as you pointed out, don't know why I missed them the other 10 times I looked, senior moment I guess.
Check ed the Frames, all is well there.
Loosened everything up on the bonnet, removed the rear stiffness from the Wings and Air Ducts and its a lot closer now, close enough to get it there I think!
Problem now is once I have it adjusted correctly, getting that same alignment when I remove the Bonnet and flip over for bonding. ( the engine etc is in the car).
I have seen what appears to be an assembly frame being used in a couple of videos, it seems to set from the hinges and hold the latch pins at the rear in the correct relationship to the hinges, in my case pulling the bottom of the wings where they meet the sill extension back to the right place a prestressing the Bonnet to the correct shape. Is this the way to go do you think?
there's an example here,
of course getting the dimensions to build this is the tricky bit, still puzzling through that one, although I have a friend with a Laser Tracker who could come in and gather all that data for me if I can't find the plans somewhere.
all the best!
Tony
firstly, thank you so much for responding, really appreciate it.
Found the dimensions as you pointed out, don't know why I missed them the other 10 times I looked, senior moment I guess.
Check ed the Frames, all is well there.
Loosened everything up on the bonnet, removed the rear stiffness from the Wings and Air Ducts and its a lot closer now, close enough to get it there I think!
Problem now is once I have it adjusted correctly, getting that same alignment when I remove the Bonnet and flip over for bonding. ( the engine etc is in the car).
I have seen what appears to be an assembly frame being used in a couple of videos, it seems to set from the hinges and hold the latch pins at the rear in the correct relationship to the hinges, in my case pulling the bottom of the wings where they meet the sill extension back to the right place a prestressing the Bonnet to the correct shape. Is this the way to go do you think?
there's an example here,
of course getting the dimensions to build this is the tricky bit, still puzzling through that one, although I have a friend with a Laser Tracker who could come in and gather all that data for me if I can't find the plans somewhere.
all the best!
Tony
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#4 Re: basic dimensions for front frame alignment
Hello Tony,
If the engine is out of the car, the bonnet without the air ducts etc can be assembled on the cars and the shut line gaps made good before the air ducts and other support features are added. Once you're happy with the fit, bonding of the the air ducts and other components requiring bonding to the bonnet can be done with the bonnet in place, from below.
We do a trial fit of the support components, so that masking tape can be applied to limit the area to which the bonding material can spread. This helps enormously when cleaning up after the job is completed. Once the tape is in place, the support components are removed, the bonding material applied (this includes a special primer for the material we use and an accelerator) and the support components replaced.
Regards,
Bill
If the engine is out of the car, the bonnet without the air ducts etc can be assembled on the cars and the shut line gaps made good before the air ducts and other support features are added. Once you're happy with the fit, bonding of the the air ducts and other components requiring bonding to the bonnet can be done with the bonnet in place, from below.
We do a trial fit of the support components, so that masking tape can be applied to limit the area to which the bonding material can spread. This helps enormously when cleaning up after the job is completed. Once the tape is in place, the support components are removed, the bonding material applied (this includes a special primer for the material we use and an accelerator) and the support components replaced.
Regards,
Bill
Last edited by angelw on Mon Feb 07, 2022 8:18 pm, edited 1 time in total.
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#5 Re: basic dimensions for front frame alignment
Thanks Bill, I'll give it a go.
Appreciate the help very much
all the best
Tony
Appreciate the help very much
all the best
Tony
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#6 Re: basic dimensions for front frame alignment
Bill,
Would you happen to know the size of the bolts that are used at the hinge to attach the bonnet to the lower valance?
I am referring to the bolts that go in from back to front.
Was playing with the shim adjustment a few months ago and somehow managed to lose the bolts.
Thanks for your help,
David
Would you happen to know the size of the bolts that are used at the hinge to attach the bonnet to the lower valance?
I am referring to the bolts that go in from back to front.
Was playing with the shim adjustment a few months ago and somehow managed to lose the bolts.
Thanks for your help,
David
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#7 Re: basic dimensions for front frame alignment
Hello David,
5/16 UNF in the thread size, but I'll have to measure one tomorrow for the original bolt length. The original bolt (actually a set screw) is somewhat longer than what one would consider required, but the extra length was to allow easier assembly and insertion of spacers. In my mind's eye, I would say that they are circa 1.5" long.
Some will say that you can use any maximum spacer stack thickness you can shoehorn in between the face of the hing and the frame of the lower valance. This is not so; 11mm (7/16") is the maximum spacer stack thickness that should be used. Any advance on that and as the bolts tighten, the mechanical advantage of the thread helix kicks in and simply distorts the cage for the threaded plate and the area of the Lower Valance where the hinges interface with it. If you need more stack thickness than that to adjust the bonnet shut line gaps, there are probably issues with the Bonnet Hinge Frame that need to be addressed.
Regards,
Bill
5/16 UNF in the thread size, but I'll have to measure one tomorrow for the original bolt length. The original bolt (actually a set screw) is somewhat longer than what one would consider required, but the extra length was to allow easier assembly and insertion of spacers. In my mind's eye, I would say that they are circa 1.5" long.
Some will say that you can use any maximum spacer stack thickness you can shoehorn in between the face of the hing and the frame of the lower valance. This is not so; 11mm (7/16") is the maximum spacer stack thickness that should be used. Any advance on that and as the bolts tighten, the mechanical advantage of the thread helix kicks in and simply distorts the cage for the threaded plate and the area of the Lower Valance where the hinges interface with it. If you need more stack thickness than that to adjust the bonnet shut line gaps, there are probably issues with the Bonnet Hinge Frame that need to be addressed.
Regards,
Bill
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