Heater core question

[timsz]

I have a note attached to my 71Z heater core. (it's out of the car). The note is partially ruined. Does foam attach to the side, top, etc. of the core? Would anyone know where it attaches or is there a picture somewhere? I can't find any. Thank you, TimsZ

[grannyknot]

Tim, I had a thread bookmarked that showed everything in the heater/blower box but just checked it and it's not live anymore. Search the archives using "Rebuilding 240Z heater/vent system PICS".

Basically you will want some kind of sealed foam or plumbers putty all around the outside of the heater core so all air flows only through it.

[SteveJ]

You could always use the Internet Wayback Machine to see if the site is archived. I've brought some old links back to life that way.

[timsz]

Thank you,TimsZ

[timsz]

I typed rebuilding 240Z heater on google and it came up.

[Namerow]

I'm in the final stages of restoring the Heater Box for my 70 Z. I measured all of the factory foam (intact, but badly aged) during disassembly so that I could duplicate later with new foam. Sorry, no pix, so I'll try to explain in words...

The job involves a total of 8 pieces of foam. Six are applied to the Core. The other two are applied to the inside of the Heater Box side plate (driver's side only).

Pieces 1 & 2: To start, you'll need 1"-thick foam, cut into long, 30mm-wide strips. It needs to be quite 'crushable', so use open-cell foam. I found a package of scotchbrite-type sanding sponges that were perfect (after I cut off the abrasive layer). You could also try the foam from a cheap floor mop. Cutting foam this thick is easiest with a long, hook-shaped X-acto blade. Just press down hard with a steel ruler along your cut line, then run the blade two or three times along the cut.

First, you'll need to apply strips along the upper half of the left (driver) and right (passenger) sides of the Heater Core, filling in the depression between the edges of the header tanks. Cut two strips of 120mm length. Glue in place.

Pieces 3 - 6: Next, cut four short lengths (35mm length each; again, all are 30mm in width). Glue two of these onto the ends of the header tanks on the driver's side of the Core. These will butt up against the fixed side plate of the Heater Box. Then glue the other two pieces onto the inside surface of the side plate (driver's side, of course) of the Heater Box, to line up with the pieces you just glued to the Core header tanks (i.e. you'll have a double-layer of foam cushioning in these two locations).

Pieces 7 - 8: The last two pieces are a bit trickier (if you want to match the OE installation). These are specially-shaped and holed in order to slip over the supply and outlet tubes of the Core. They're also vinyl-faced (on the side that will face outboard and butt up against the passenger-side side plate of the Heater Box (i.e. the removable side plate). I used the same 1-in. -thick foam as before. Glue thin flexible vinyl sheet onto one side before you cut the pieces to shape. Now:

Cut two rectangles (57mm x 37mm for the rear Core tube location; 43mm x 35mm for the front Core tube location). Now you need to make a hole in each piece so it can slide over the Core tube. The hole in each piece should be 15mm diameter. In each case, it will need to be positioned quite off-centre... For the rear tube's pad, the hole will be biased towards the upper rear corner of the pad. For the front tube's pad, the hole will be biased towards the upper front corner of the pad. To locate the hole centre in each pad: From the top outboard corner of each rectangle, measure in 15mm and down 15mm to locate/mark your centre). Once marked, it's easier to punch out the holes rather than trying to cut them out. Make a punch from a suitable-diameter piece of thin-wall tube (sharpened by chamfering one cut end). Once finished, just these two pieces over the Core tubes. No glue here. The long dimension of each piece runs horizontal.

I had great results using 3M 80888 sprayable contact cement. Requires a lot of masking off off the Core and the Heater Box in order to avoid getting it in the wrong places. Do NOT use this glue indoors (it's really hard on the lungs -- probably explosive, too). If you follow the directions, this glue gives you a ~5-minute grace period where you can adjust your positioning before clamping.

Before you slide the Core back into the Heater Box, apply a (very) thin smear of white grease on the surfaces of the 'shelf' brackets so that the Core slides in nice and EZ.

Hope this helps.

[timsz]

Thank you, TimsZ