Hood Scoop - internal vs external flange

[mopowers]

For those who've install fiberglass hood scoops on steel hoods, do you prefer using scoops with external flanges or internal flanges? Seems like the internal flange would be difficult to mechanically secure but would ultimately require less body filler to blend.

What do you all prefer??

 

[MV8]

For a bolt-on with no filler, internal is easiest. I've used flangeless scoops after grinding the edges to match the hood curvature, as a bolt-on by bending and glassing threaded rod into the shell with washers under the hood and nyloc nuts.

 

[BrianT]

I went with an internal flange scoop and it was actually a pretty easy install. No bondo necessary.

 

[Demonracer]

I have a glass hood and had a Pro Stock style scoop installed by a fellow racers body shop. We opted to slot my hood and put the flange on the underside. Our thinking was that it would be less prone to cracking when the hood started lifting slightly down track. So far, 10 years later there are no signs of cracking.

 

[mopowers]

Thanks guys. Internal flange units do seem a little easier to finish. What fasteners are typically used to attach scoops with internal flanges? Do you run bolts from the top, or glass in nuts or rivnuts on the scoop side?

I went with an internal flange scoop and it was actually a pretty easy install. No bondo necessary.

View attachment 1716417952

Nice work. How visible is the flange? What fasteners did you use?

 

[tjpatte]

I went with an internal flange scoop and it was actually a pretty easy install. No bondo necessary.

View attachment 1716417952

Nice Brian, don’t happen to have a side shot?

 

[BrianT]

How about this one? @mopowers the flange isn't visible at all unless you're looking into the scoop? The flange had hardware set into the fiberglass. I just set the scoop where I wanted it, marked where the bolts were and then drilled the holes. Easy peasey

 

[mopowers]

How about this one? @mopowers the flange isn't visible at all unless you're looking into the scoop? The flange had hardware set into the fiberglass. I just set the scoop where I wanted it, marked where the bolts were and then drilled the holes. Easy peasey

View attachment 1716418277

So, the bolts were fiberglassed into the flange. That does make it easy.

 

[tjpatte]

How about this one? @mopowers the flange isn't visible at all unless you're looking into the scoop? The flange had hardware set into the fiberglass. I just set the scoop where I wanted it, marked where the bolts were and then drilled the holes. Easy peasey

View attachment 1716418277

That is Clean, well done!