Bonnet conversion.. gas strut / heat issues?
Discussion
Evening all. Thought i'd start a thread rather than this get lost in one of the others.
Having had my bonnet conversion now for around 1500 miles, i've noticed that the main bonnet has started to warp/distort at the point where i've mounted the top of the gas struts to. I think it's a combination of the under bonnet temps, and the fact that the struts will be putting a small amount of constant pressure on the bonnet.
I have some spreader plates fitted behind the strut mounts, but being metal i'm wondering if these are heating up themselves and thus causing the fibreglass to become more pliable than normal?
So... anyone else who's done this conversion, have you seen anything similar? Or how have you mounted the tops of the gas struts?
I haven't figured out my next step yet. It'll either be to add even more reinforcement to the side section of the main bonnet where the struts mount to (i'd already added a bit of fibreglass). Or i might ditch the struts and go for an old style bonnet stay. Here's the bit affected in case this is making no sense!
Having had my bonnet conversion now for around 1500 miles, i've noticed that the main bonnet has started to warp/distort at the point where i've mounted the top of the gas struts to. I think it's a combination of the under bonnet temps, and the fact that the struts will be putting a small amount of constant pressure on the bonnet.
I have some spreader plates fitted behind the strut mounts, but being metal i'm wondering if these are heating up themselves and thus causing the fibreglass to become more pliable than normal?
So... anyone else who's done this conversion, have you seen anything similar? Or how have you mounted the tops of the gas struts?
I haven't figured out my next step yet. It'll either be to add even more reinforcement to the side section of the main bonnet where the struts mount to (i'd already added a bit of fibreglass). Or i might ditch the struts and go for an old style bonnet stay. Here's the bit affected in case this is making no sense!
you know what you have just made a crap eve just slightly Better! Sorry to hear whats happened, i have been struggling with the same problem and i havent even mounted the struts properly yet. I had them in 24 hours, came back to it tonight and had probs with that same area. I thought it was just me being a prat. Somehow the securing studs at this point at one side had stopped lining up. I thought it was the pressure from the strut and let some out, i bloody over did it and the strut now wont hold the bonnet up that side . . . So got to call sgs 2moro and find out what i can do
Anyway, i think my bonnet was slightly twisted in this area already as i always had to use the nuts on the studs to get the bonnet to sit down for the service bonnet pins to engage properly. . . What did you do about these? How is your alignment at the top of the bonnet? Mine needs moving again! I actually think it will be ok with a little adjustment and the new strut . . .
Anyway, i think my bonnet was slightly twisted in this area already as i always had to use the nuts on the studs to get the bonnet to sit down for the service bonnet pins to engage properly. . . What did you do about these? How is your alignment at the top of the bonnet? Mine needs moving again! I actually think it will be ok with a little adjustment and the new strut . . .
hi dave, having bought one of your first sets of hinges i probabily have had them on for the same ammount of time tho for a longer distance than you, and have done some rather spirited driving on and off track with some very warm temperatures! i have mounted my gas struts as per the surface and design method, and the only sort of mis-shaping i have is where the top of the original bolting points are but this might be because of me not bolting it down any more.
with regards to your problem are you gas struts permanetly pushing on the bonnet? once mine reaches 3/4 closed the support from the struts is non-existant, if anything it actually helps keep it closed. when closed my struts are close to full compression, is it the same with yours? i have re-inforced the sides of the bonnets, tho this is the only re-inforcing i have done. i hanven't re-inforced where the hinges bolt to the main bonnet, not where the gas struts mount to the top of the arch. as of yet i have not had an problem with cracking of the fiberglass nor does my install seem flimsy (altho there is some minor stress crack on the bonnet hignes but this was due to me over tightening!)
with regards to your problem are you gas struts permanetly pushing on the bonnet? once mine reaches 3/4 closed the support from the struts is non-existant, if anything it actually helps keep it closed. when closed my struts are close to full compression, is it the same with yours? i have re-inforced the sides of the bonnets, tho this is the only re-inforcing i have done. i hanven't re-inforced where the hinges bolt to the main bonnet, not where the gas struts mount to the top of the arch. as of yet i have not had an problem with cracking of the fiberglass nor does my install seem flimsy (altho there is some minor stress crack on the bonnet hignes but this was due to me over tightening!)
Rob - The alignment on my bonnet was ok before. The hols for the middle studs weren't perfectly over the centre of the stud but I never needed to put any pressure using the middle studs in order to help the service bonnet catches work. I only used to put the nuts on the middle studs and do up enough to be finger tight. I think SGS can re-gas the struts for you?
Stu - would you mind trying to take a pic of your struts when the bonnet is almost shut? What kind of plate/reinforcement are you using at the point where they attach to the bonnet? I didn't like the S&D solution as it restricts access so hopefully I can come up with a solution that's the best of both!
Ben... If you're having trouble with the service bonnet catch coming undone then this might indicate the edge of the bonnet is starting to move slightly due to the gas struts. Using your pic.. what's happened to mine is that when the bonnet is shut, the pressure from the strut is pushing outwards from the centre of the car.
The "lip" that the strut is mounted to has bent outwards slightly and the clearance between the service bonnet and the main bonnet has closed up. When going over some bumpy ground the service bonnet catch has released. This was the trigger for me to take a proper look and realise that the main bonnet has changed shape slightly.
Where you have the reinforcing plates, i'm thinking maybe bond and L shape plate onto the bonnet to stop the lip from bending outwards?
Stu - would you mind trying to take a pic of your struts when the bonnet is almost shut? What kind of plate/reinforcement are you using at the point where they attach to the bonnet? I didn't like the S&D solution as it restricts access so hopefully I can come up with a solution that's the best of both!
Ben... If you're having trouble with the service bonnet catch coming undone then this might indicate the edge of the bonnet is starting to move slightly due to the gas struts. Using your pic.. what's happened to mine is that when the bonnet is shut, the pressure from the strut is pushing outwards from the centre of the car.
The "lip" that the strut is mounted to has bent outwards slightly and the clearance between the service bonnet and the main bonnet has closed up. When going over some bumpy ground the service bonnet catch has released. This was the trigger for me to take a proper look and realise that the main bonnet has changed shape slightly.
Where you have the reinforcing plates, i'm thinking maybe bond and L shape plate onto the bonnet to stop the lip from bending outwards?
Hi Dave et al,
OK, I've mounted my struts in the same position as (seemingly) everyone posting on this thread.
I've used 2mm x 25mm (about 100-150mm long)flat ali bar shaped to the curve of the bonnet masticked and bolted with M4 c/sunk bolts - nylock nuts engine side, to brace the area where the strut 'ball' attaches. I did the conversion about 4 months ago now and I cant see any bonnet distortion.
All the catches and studs still 'mate' with the holes/fixings on the large bonnet.
All the fixings for the hinges and gas strut top and lower 'balls' are in stainless metric bolts - c/sunk as appropriate.
The car has been up to STR8Six and received no comments re: problems closing. In fact Jason/Mark etc said how much easier it is to work on.
Nick
OK, I've mounted my struts in the same position as (seemingly) everyone posting on this thread.
I've used 2mm x 25mm (about 100-150mm long)flat ali bar shaped to the curve of the bonnet masticked and bolted with M4 c/sunk bolts - nylock nuts engine side, to brace the area where the strut 'ball' attaches. I did the conversion about 4 months ago now and I cant see any bonnet distortion.
All the catches and studs still 'mate' with the holes/fixings on the large bonnet.
All the fixings for the hinges and gas strut top and lower 'balls' are in stainless metric bolts - c/sunk as appropriate.
The car has been up to STR8Six and received no comments re: problems closing. In fact Jason/Mark etc said how much easier it is to work on.
Nick
Cheers!
I think it's down to where i've mounted the lower section of the strut. It's quite "inboard" so there was a small amount of pressure directed outwards. I've got a long length of right angle aluminium so i'm going to fix it, and bond that to the inside of the bonnet so it provides some reinforcement. Also, now my rubber rivnuts have arrived, i'll mount the lower ball joint a little more towards the outside of the car. This will ensure any force that is present is directed more along the line of the bonnet!
Will update with some pics once i've re-done.. got some more things to do first. Namely driving it!
I think it's down to where i've mounted the lower section of the strut. It's quite "inboard" so there was a small amount of pressure directed outwards. I've got a long length of right angle aluminium so i'm going to fix it, and bond that to the inside of the bonnet so it provides some reinforcement. Also, now my rubber rivnuts have arrived, i'll mount the lower ball joint a little more towards the outside of the car. This will ensure any force that is present is directed more along the line of the bonnet!
Will update with some pics once i've re-done.. got some more things to do first. Namely driving it!
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