Clamshell Wings - The Fixing Of......Why use Rivnuts??

[Tazio]

I am just beginning the process of stripping a BDR down to refurbish it. The aim is to keep its originality including the Clams.  The existing wings are held on by M5/6 bolts into rivnuts, mostly rusted in solid, requiring the heads to be ground off ( thanks Ian).  

The question I have is why were/are rivnuts used?, what are the benefits? Couldn't I simply use nuts bolts and appropriate sized large washers inside the body to spread the load as an alternative?

Anyone have any views?

Alan

[Jonathan Kay]

The convenience of only needing access from one side?

Jonathan

[ECR]

I'd do as you suggest. A large washer will spread the load better. The only concern is corrosion caused by dissimilar metals ( but you have that in the rivnut set up. You could coat the washer with duralac ( ?). The paste that Elise owners use to stop corrosion of this sort

[Rex]

I use stainless steel bolts, nuts and large washers.  I use large rubber washers under the stainless steel ones.

[Tazio]

Thanks gents, seems like a plan...

[CharlesElliott]

Can you actually access the inside for all of them?

if you can then the only downside is the damage it will do to the body if one gets hit/ripped off. 

[Wrightpayne]

I was assisting Tazio with removal and didnt understand why, in the boot the wings attach with nuts, bolts and penny washers but in the engine bay rivnuts?.

I think there are a couple of rivnuts needed aside the footwell but rest can be N&B’s.

Its great attacking someone elses car with an angle grinder :-0

Ian

 

[elie boone]

Apart from the big bolt that goes in to the frame i used alloy bolts to hold the clam on.

[Jonathan Kay]

... in the boot the wings attach with nuts, bolts and penny washers but in the engine bay rivnuts?.

In my 1998 build the rear wings had some blind rivet nuts and some nuts and bolts.

And as soon as I heard about the advantage of fitting sacrificial bolts I changed them all to nylon. Does anyone do that for clamshell front wings, and, if not, what's the difference? Greater aerodynamic forces?

Jonathan

[Jim 123]

Probably not very significant, but I'd assume that removing the rivnuts will leave an oversize hole in the side skins for existing diameter bolts.  Are you going to rely on clamping load to prevents gradual movement or drill the clamshells to take a slightly larger bolt?

[elie boone]

An rivnut for a 5mm bolt is leaves a 7mm hole, if you replace this with a 6mm bolt that is not too bad.

[Wrightpayne]

Jim,

Side skins being replaced as part of the chassis refurb so will need to drill new holes anyway.

Jonathan,

Clamshells are fixed to the front headlight brackets and have two larger bolts along their length into threaded bosses in the chassis. The smaller bolts into rivnuts are probably of lesser significance (IMHO).

The rear wings have rivnuts where the back of the panel is inaccessible, where it transitions from boot space to cockpit. 

Regards

Ian

[Wile7]

RE Rivnuts - I don't care - the fact that you are keeping the original Clams on a BDR makes me like you very much  

 

[Tazio]

Why thank you Wile, I think its important to keep it as original as I can, it has S type seats in so they have to go, have bought an original pair of 1992 seats that need to be re-covered. One concession to modernity are adjustable front top links to have some control over camber.... Don't talk about colour though...struggling with that..lol

[Paul McKenzie]

Got to be BRG, Tazio (just like mine, which you've seen - BRG with clams)

[Tazio]

Been thinking of Jaguar Racing Green from the D type era, with a noseband and rear panel in Toyotas 'Solar Orange' ....but there;s time to think of loads of others lol.