Aluminum on outside of footboxes?

[westva]

I am building HM 2003. Hurricane no longer uses aluminum on the outside of the foot boxes. I am thinking about making the aluminum panels and attaching them to the outside of the foot boxes. My plan is to attach them with 3/16 rivets. Is there any reason not to use the aluminum panels? Can I expect any problems such as the rivets not holding in the fiberglass tub? Should I use washers and/or a strip of aluminum on the inside of the tub to help hold the rivets from pulling through?

I do have the heat shield tape on the foot boxes.

[1985 CCX]

Here is my two cents

1) Use small spacers between aluminum and the glass footbox to creat an air gap. (1/8")
2) Use 1/8" rivets with 1/2" - 5/8" reach
3) 1/8" Locking rings on the inside of box as it will help with securing them.
4) Aluminum rivets are ok as you are only contacting glass and aluminum. When connecting steel to glass use SS rivets as dissimilar metals will not hold out.
5) Original cars only had glass, I have seen some asbestos insulation however I would not go that route.

Have fun!

[YerDugliness]

Originally Posted by westva

I am building HM 2003. Hurricane no longer uses aluminum on the outside of the foot boxes. I am thinking about making the aluminum panels and attaching them to the outside of the foot boxes. My plan is to attach them with 3/16 rivets. Is there any reason not to use the aluminum panels? Can I expect any problems such as the rivets not holding in the fiberglass tub? Should I use washers and/or a strip of aluminum on the inside of the tub to help hold the rivets from pulling through?

I do have the heat shield tape on the foot boxes.

I've been a long time fan of the Hurricane product, westva....has the "new" Hurricane stopped offering the aluminum cover option? The footboxes were never aluminum, but Hurricane did offer an aluminum overlay.

If Hurricane has stopped offering that option, I can see that you would be able to do as you suggested, but I agree with Jeff that you should leave a small air gap between the aluminum covers and the fiberglass footboxes. That will provide a bit of heat resistance, and we all know that the footboxes can get VERY warm from the heat radiated by the headers. On my cobra replica (sadly, NOT a Hurricane), there is a small heat shield between the header and the footbox on the driver's side, but none on the passenger's side. The difference is quite noticable on any day when the ambient temperature is 80* or above.

I am going to approach the heating of the footbox area by using a radiant barrier on the inside of the cabin, between the fiberglass and the carpeting, but if it is not adequate, I'll be adding a layer of metal of some kind, aluminum or stainless steel, to the front of the footboxes in the engine compartment, and it will be separated from the fiberglass by perhaps as much as 3/4".

Good luck on your new Hurricane.....

Cheers from Dugly

[westva]

Hurricane still offers the aluminum above the foot boxes that goes against the firewall, but not the aluminum that goes on the foot boxes. Hurricane does send stick on heat reflective material. Do you think I need to space the aluminum out from the reflective heat material?

[s_reynolds]

Westva, I have the Gen I Hurricane and on the Gen I models the alum panels were riveted with 1/8" alum rivets directly over the heat shield material on the foot boxes.

Regards, Sam

[Sminor]

Hey Westva,
I put aluminum on the outside of my footboxes. I used bolts to attach the aluminum sheets, and like 1985 CCX recommended, I used spacers between the footboxes and aluminum to create an "air-gap." I have a big block FE in my car and have never noted excessive heat in the footbox. Hope this helps, Steve

[elmariachi]

Some experience from Hurricane #6, which has a 427 FE and now has 6k miles in South Texas heat and humidity. More important than any hear barrier is the flanged headers and side pipes. If you have the slip-fits, you need to flange them before doing anything else. If possible have at least the headers ceramic coating as its does make a huge difference.

With regard to the footboxes, I doubt an air gap would provide any measurable temp difference. What will significantly affect foot box cabin temps is using some sort heat barrier sheeting. I bought a few pieces from Pegasus Racing and used them behind the footbox sheet metal, which is then riveted in place using 1/8 rivets 3" apart. If you buy the right length rivets they will pull and hold just fine no backing required.

I also used the same barrier inside on the front and side footbox walls under the carpet. The interior floor area was brutally hot until I flanged the exhaust but now its fine. Short of Space Shuttle tiles there is nothing you can do to completely negate the heat. But the barrier material is far more important than any air gap in my opinion.

Here's how I did mine and I have not had one single rivet come loose:

[LMH]

I have a heat shield between the outer aluminum sheet and the fiberglass footbox's. I didn't do an air gap but I like the idea. I used aluminum washers on the inside with the rivets. Ace hardware sells the washers.
Larry