Engine Side Valances for Spitfire 1500

by Andrew Miller

I have prototyped two styles of engine side valances. The first style is a 1/8" masonite substrate wrapped in fibreglass, the second is the same substrate sandwiched between an aluminium sheet and fibreglass (the aluminium sheet faces the engine - opinion seems divided as to whether this heat reflector is a good thing or a bad thing). Two local LBC mechanics use aluminium exclusively, two use fibreglass panels (although they are not sure where they come from) and a fifth asked "why did I want valances ?"

I recommend the fibreglass wrapped valance, if you use coloured resin you can 'adjust' the valance for fit with a a surform or sandpaper (or in extreme cases, a belt sander) after the fact (please be aware that the sanding dust contains glass fibres and is very itchy). The aluminium sand which style has less flexibility for installation.

P. S. Although for straight ease and cost a masonite shape painted with one of the rust paints or polyurethane paints would work as well. I originally planned to make two sets. One for myself and one for the fellow who supplied the dimensions (Thanks Rod !) out of fibreglass or resin coated masonite. This took a long time. On reflection I would argue that primed and painted masonite is still better than the 20 year-old cardboard.

If you still have an air pump, I found it easier to build the 'tent' from aluminium and rivets and bolt in place rather than trying to create one form drawing and masonite. Since I no longer have an air pump fitted I wasn't able to trial fit.

Tools Required:

Style 1, jigsaw, ruler, pencil, paintbrush to be sacrificed to the God of epoxy resin, Boddingtons, Ruddles or Kilkenny.

Style 2, jigsaw, ruler, paintbrush to be sacrificed to the God of epoxy resin, metal shears, utility knife, drill, pop rivet gun, Newcastle Brown, Smithwicks or Guiness.

If you do elect the fibreglass route - I recommend fibreglassing the masonite prior to final cut and trim. Fibreglassing over cutouts was a pain.

Materials:

I bought some Aluminium flashing/Aluminium repair patch sheets from Home Depot (10' x 2') it was approx $ 14.00, this is enough to make two valances, make mistakes on many more and have enough aluminium to make a spare set.

Fibreglass cloth and resin. If you want to get fancy and avoid painting the fibreglass later, check out the specialty stores for epoxy colouring agents. Fibreglass must be done outside or in a very well-ventilated area!!!

Spitfire right side engine valance (as viewed from the tyre side). The valance has only two 90 degree angles, the top right (M) and the bottom right (unlabelled). I used *" masonite originally, but the fibreglass sandwich seems to be strong enough. There is no structural component to the valance, it seems to protect the expensive bits from road spray, rocks, marmots etc.

To aid in reproduction, I have not taken any angle measurements - I have provided points to connect as lines. The finished valance is the polygon described by B-M-bottom_right_corner-K-H-G-J-C

Start with a project sheet of 1/8" masonite (hardboard) 22"(width) x14"(height) [A->M=22"], [A->D=14"]
Mark the following points

AB = *"
AC = 10 *"
AE = 8 1/8"
AF = 16 *"
EG = 6"
FH = 6 *"
DI = 7"
IJ = 3 *"
DL = 16 *"
DK= 16 *"

Draw the lines

B to C
E to I
F to K
C to J
G to H

Draw the radii

G and H is 1 *"
point L is 3"

This is the carb side engine valance, the following adjustments are required to fit your particular setup

the top edge must be shaped to fit the carb setup/manifold/air filters. If you still have the metal top edge from the original valance it may be used as a template. My car was originally a single ZS converted to duak SU-HS4 with K&N's so any hope of reusing things was lost.
the brackets for firewall connection and radiator frame connection must be marked

Once the masonite is shaped construction may begin. The finished product is an aluminium, masonite, fibreglass sandwich. The alumium is fastened to the engine side of the valance, the fibreglass side is waterproof and road slime resistant and so faces the fenders (wings)

Aluminium I traced the 'adjusted' masonite template on the aluminium and cut 1 *" oversize on all sides. I used a standard utility knife and a straight edge to score the straight edges and coaxed the rest with a combination of knife and shears I then folded the oversize edge over the masonite, slitting the aluminium as required to make the three radii Once folded over, I secured the aluminium sheet with 1/8" aluminium rivets from a handheld pop rivet gun Fibreglass Mix a small amount of epoxy resin in a disposable container 'paint' the side to be fibreglassed place the dry cloth over the now sticky surface 'paint' enough resin over the cloth to cover any dry areas Cover the epoxy resin with a sheet of kitchen wax paper (this gives it a smooth surface as it dries ANDreduces the potential of something valuable coming into contact with the resin ) (tools, skin, hair on your forearm etc. use a 'Surform' or a sheet of coarse sandpaper over a small wooden block to 'ease' the edges Mounting and Installation Mark the holes for the mounting hardware prepare, prime and paint as required. (The original valances were unpainted cardboard (??), perhaps paint to match hoodsticks, the jack which is absent from the bootÉ) The distributor side of the engine valance B-C-K-L-M-J-H-G-I

The left side valance is a piece of masonite 23 *" wide, A-D = 23 *" and 17 *" high, A-B=17 *" Mark the points AC=1" ,draw the line BC DE = 6 *" ,draw the line CE KE =1" FL = 1" DF = 9 *" draw the line KL and LM AN= 7 *" AO = 11 5/8" BI = 5 *" BJ = 12 *" draw the line NI and OJ NG= 10 *" OH = 10 *" draw the line GH , the radii at G and H are also 1 1/4" Cut out the valance C-K-L-M-J-H-G-I-B Adjustments

This is the distributor side valance, the following adjustments are required to fit your particular setup

the edge above must the line GH may need to be shaped/extruded to fit the air pump (if applicable)
the brackets for firewall connection and radiator frame connection must be marked.