GD Heater Box.

[Trigger]

Hi Guys, anyone know how to shoe-horn the heater box into the passenger side footwell void? The mounting flanges stop the box going right in and right up. The cover won't be able to go on and the water outlets will be too low. I can "adapt" it but would like to fit it the "right" way. I have the pictures that were put up on the site put can't see enough detail for them to help me. Cheers for any help, Trigger.

[SimonP]

Hi Trigger,
I didn't have too much trouble with mine, but I found that self tappers weren't the best thing to secure it, due to the limited clearance on the sides, so you can't get much leverage on a screwdriver.
Unfortunately these clearances prevent detailed photos being taken too.
I marked and drilled the inner two holes through the bulkhead, then used nuts and bolts (M5) to secure the unit. The outer fixings were still self tappers.
I had to make the ducting holes through the bulkhead oversize in order to get the unit to fit comfortably, otherwise it would have been forced against the bodyshell.
Here's a photo of how my heater connectios line up:
http://www.cobraclub.com/crcforum/user_files/3043.jpg

I think I also had to trim a little off the mounting flanges.

Simon.

[Trigger]

Thanks for the reply Simon. I did get it last night as I was out till late. Tried again this morning with a template to figure out how much to cut off the flanges but even with the end covers off and the matrix in the box the water elbow is preventing the box from going where it needs to be. Looks like the whole unit is just too big for the space provided. Lunchtime now so will think of other things to try during that. Waste of time. Two days to fit the heater ... so far!

[craigh]

it is a bitch of a job,i made a template of the mounting holes with card and transferred these to the bulkhead to drill and fix with nuts and bolts,it had to go as far up in the compartment as possible to get it to fit but i didnt have to cut away any metal.
the hoses exit on the right hand side looking from the front of the car,the elbow is quite tight to the side of the compartment,this was my best position maybe the internals of the underwheel compartments differ slightly

[chris m]

I'm about to fit my heater soon, so this thread is very timely! The instructions say you should use self tappers though the hole in the heater flanges, mine hasnt got any holes, did you have to drill them?

Chris

G.D. Chevy 350

[Trigger]

Hi Guys, I did the necessary butchering to the body work to get the body of the box into position. It will now fit in the space but I will still have to cut the right-hand mounting flange for it to fit in place. I made a template of the back of the box and then cut off the right hand flange from the template to get it to fit. Now I can see how it fits in I will be able to judge how much to take off the right hand flange actually on the box. No need to cut off the left hand flange as clearance is needed for the water connection elbow, hose elbow and hose clip. I still have to mark and cut the holes for the ducts and water connections but with the template this won't be too difficult. I think it will be better to fix in position with screws, nuts, washers rather than just self-tappers.

I'm not too happy about having to do this cutting and hacking. This is why I called on the forum for help just in case I was doing something wrong but there was no way to get the box in without. I used a Dremel type tool to get in there. I don't know if my body is different from others but this is what I had to do. I know we can all do what's required but these kits are not cheap and after sourcing all your parts from the manufacturer one would expect things supplied to fit. If you're using your own sourced parts well you would have to do the necessary.

Happy hacking ... Trigger!

[Robin427]

>I'm about to fit my heater soon, so this thread is very
>timely! The instructions say you should use self tappers
>though the hole in the heater flanges, mine hasnt got any
>holes, did you have to drill them?

Mine hasn't got any holes either, but I'm not too worried about drilling them. Can I not use bolts to mount the thing, though? I don't like using self tappers when I can possibly help it.

Could someone point me in the right direction as to where the water inlets and outlets go through into the engine bay, please? (and which is which and where does the rubber elbow go...?)





Robin

Drive it like you stole it...
http://www.creffield.com/cobra/index.html

[Happy Jim]

>Mine hasn't got any holes either, but I'm not too worried
>about drilling them. Can I not use bolts to mount the thing,
>though? I don't like using self tappers when I can possibly
>help it.
Nothing to stop you using bolts, but how are you going to hold the head and the nut ? it's a long way to stretch Just to cheer you up, I found fitting the heater box one of the most frustrating bits of the build, not hard just a pain in the Ar&e



>Could someone point me in the right direction as to where the
>water inlets and outlets go through into the engine bay,
>please? (and which is which and where does the rubber elbow
>go...?)

If Simon hasn't got a snap I'll do one tomorrow :tu

Cheers

Jim

[SimonP]

Robin,
The problem you will have is on the right hand side of the heater box (as you look at it from under the wheel arch).

Remember that nice PU-foam-filled wing section that Andy B jumps about on in the demonstration....well that's where the other side of the bolts end up.
I recall that I could just-about see the trace of the bottom hole on that side, so I cut a small (15mmx10mm) hole in the inner wing panel in order to get a nut and washer on.
Using bolts on the other side makes things easier (if you have an assistant to run the nuts on!)

Once you have the heater box mounted, you can plot the hole centres.
Start with the one nearest the front of the car, which the pipe goes straight through to.
The holes will be about 25mm, but it isn't easy to get them 100% first time.
So, drill a small hole, say 3mm and use a piece of welding rod or similar to gauge where you are in relation to the heater outlet.
Assuming the hole is somewhere near, remove the heater box then drill the hole out to 13mm, then open it up further with a round file.
As the hole approaches the correct size, you should be able to use a half-round file. Keep re-fitting the heater box to check alignment.
http://www.cobraclub.com/crcforum/user_files/3714.jpg

The Elbow:
Fits on the rear connection, which exits the heater from a brass elbow.
Trim some length off the vertical leg of the elbow to allow the horizontal leg to be at the same height as the straight front connection when installed. Don't fit the jubilee clip yet.
Next, measure the horizontal centres between the connections.
You can then plot this back from the hole you have already done.

Final fitting:
This is a real cow. Depending on the minor variations between bodies and heater assemblies, you may find one method a struggle, the other impossible!

1) Fit the elbow to the heater box, then tighten the jubilee clip.
The worm-screw MUST be against the heater box for clearance to the inner wing.
Ease the assembly into place, using whatever implement you have handy in order to get the elbow to go through the inner wing.

2) Drop the jubilee clip over the heater elbow (same way round as above, but make sure it's adjusted out enough) then loosely fit the heater box. Thread the rubber elbow through the inner wing into the heater elbow, then ease the jubilee clip into place and tighten.

The jubilee clip will be hard against the inner wing, as you can see here:
http://www.cobraclub.com/crcforum/user_files/3712.jpg
Not much room for a screwdriver!

Here's how they connect to the engine. The one with the rubber elbow is the heater inlet.
This pic will also answer your bonnet seal question!
http://www.cobraclub.com/crcforum/user_files/3668.jpg

Simon.

[Trigger]

Hi Simon, very good description. I did mine a little differently as the box would not fit in without modifying the right hand side of the compartment and the mounting flange. I secured my box by replacing the self tappers on the outlet nozzle plate, drilling out the holes and replacing with screws which I then nutted tightly. Drilled the bulkhead and offered up the box passing the screws through and nutted inside the car. The mounting flanges keep the body of the box away from the bulhead to give clearance for the nuts. I then drilled through the flange holes that I could get at and screwed and nutted up. The straight inlet I projected on to the engine comp wall by slipping a short piece of hose on to the stub pipe then pushing it against the wall and drawing round it. The elbow side by measurement from the first hole.

Question: How do you know the elbow side is the inlet? I would have thought the hot water would go in at the upper straight stub and drop down the element as it cooled in a thermo-syphonic fashion. I know the water has to rise again to get out through the elbow and I know the water is pumped through in a fashion from the connection to the water pump but it still seems wrong to go in at the bottom!!