1968 Spitfire Mk3 - Replace heater ducting

[Rockape]

So, one job leads to another.
 

Replacing driver’s side crash-bar and glove box, and found the routing of the corrugated pipe from the heater to the windscreen demister fitting to be extremely tight. And, I guess it’s the original plastic piping as it pretty much fell apart….picture of the piece that came off attached!

but how do you get access to the heater to replace the duct tubing? Please someone tell me I don’t need to remove the dashboard ! 
 

i could buy a 90° joint section to reconnect this piece … that might be an option too….

[Josef]

I’m assuming Spitfire? This is what the roundtail heater fitment looks like. You can probably get to it lying with your head in the footwell, depending on how the hose clamp has been fitted previously. 

[Josef]

Err yeah, Mk3 Spitfire, it’s in the post title… Managed to forget in the 2 mins between taking photos and posting!

[Rockape]

Thanks Josef….i will have another look - maybe I didn’t have my head far enough into the footwell yesterday ! 
 

i note from your photos you have added the sound deadening stuff….i have done the same!

[Colin Lindsay]

I bought 60 sheets of the stuff recently (Dodomat / Hexmat) with the intention of coating the Herald floorpans and bulkhead but the worrying thing was the weight - the box weighed a ton. It arrived through the post like a wrapped concrete block. I'm wondering how much weight that will add to the car?

[Rockape]

Well - the obvious answer is it will add the weight of the box when it arrived.

 

joking aside - I agree….clearly it is adding a few kilograms . But the Spitfire weighs around 750 kg. 10kg of sound deadening will add about 1.5% to the weight of the vehicle. Compare this with the weight of a passenger !

 

unless you are building a machine for racing, I don’t think it’s an issue TBH.

[Josef]

Well I’ve had my Herald for 14 years now and the only insulation it has is the remains of some factory fitted stuff on the drivers side bulkhead. It definitely gets too warm so I figured it was worth a go with the Spitfire! Had the same thought process about weight too, and also decided it probably didn’t matter. 
 

Haven’t put any in the boot on mine. Might do the rear arches though now looking at yours. 

[PeteH]

The long term project 13/60, is going to get some modern sound and thermal insulation/deadening material. I well remember how noisy and "warm" SWMBO`s Vitesse got back in the 80`s. I cannot see 10 kg of improved comfort making much of a dent in performance. (the weight of a small child?). Our dog Weighs in at 8Kg.

🤣 Head of security!.

Pete

[Colin Lindsay]

I was only wondering, as if it weighs the same as a concrete block then it's like driving about all the time carrying a concrete block. No interest in improving performance, however, fuel economy... yet it does make me wonder when we have owners running about fitting everything from alloy distributor pedestals to alloy waterpump housings and carrying a ton of spares in the boot.

And no you'll never see me in lycra, I once wore a wetsuit and looked like Flipper.

HOWEVER: back to the original topic - has anyone ever found a good suitable t-piece for this type of ducting?

[Clive]

on my mkIV I eventually found some very flexible silicone ducting the correct diatemer, and it was wire wound (thing a stretched out spring, stops it collapsing) . Only downside it is orange, but not seen.

And yes, I have always managed to sort ducting by inverting and inserting myself in the footwell. A decent light, headtorches are good, and glasses that don't keep falling off are a big help. An extensive "vocabulary" makes you feel better too. 

As to fittings, I wonder if 40mm waste fittings are correct size?

[Peter Truman]

On the Vitesse heater outlet distributor I used plastic pipe fittings bends (non pressure I think) but I had to ream out the female socket a little so it would fit over the steel duct outlet, made the set up a lot tidier and sprayed it black so disguised.

[dougbgt6]

2 hours ago, Colin Lindsay said:

HOWEVER: back to the original topic - has anyone ever found a good suitable t-piece for this type of ducting?

Canley GT6 bits, more of a "Y" piece.

Doug

[Colin Lindsay]

Interesting!! I'm debating a small modification to a larger modification in my Herald; when I bought it, the heater was very very good (amazing given that the rest of the cooling system was clogged to death and ran on pure water) but this was traced to the fact that the PO had disconnected the screen demisters and placed angled pipes over the outlets so that there was tons of warm air to the feet.

Curious idea, but very practical! If you look at the original design there is a moveable directional flap which directs the warm air but there's no priority for the feet; it's either full on screen or half screen / half to feet and if you move it too far, it's off completely.

What I'm debating is keeping the passenger side as in the photo (with a bit of a tidyup to make it more professional looking) but splitting the driver's side so that there's still heat to the screen, albeit reduced flow as it's not split to left and right - hence the need for a t-piece. This means I can still clear the screen if needs be, the Herald being intended to be a fair-weather car only (but you can't guarantee the weather all day!) and so 'Er Indoors will get maximum heat to the feet which should stop that whining noise from the front of the car. Plumbing t-pieces all seem to be heavy duty and too heavy for the tubing. I do have so much spare tubing lying about I could probably do a cut-and-splice but I'm exploring the options.

The original tubing seems to be about 1.5 inch.

 

 

[Clive]

48 minutes ago, Colin Lindsay said:

Plumbing t-pieces all seem to be heavy duty and too heavy for the tubing. I do have so much spare tubing lying about I could probably do a cut-and-splice but I'm exploring the options.

The original tubing seems to be about 1.5 inch.

 

 

Plastic waste fittings are very light, and available in white, grey and black, There are different sizes of fitting too (solvent weld and push fit) and I can measure some when I stumble across my box of leftover fittings. Cost about 80p each. 

[NonMember]

51 minutes ago, clive said:

I can measure some

Plastic waste pipe comes in a number of standard sizes, but I think 1.5" is one of them (1.25" is also common)

[Clive]

15 minutes ago, NonMember said:

Plastic waste pipe comes in a number of standard sizes, but I think 1.5" is one of them (1.25" is also common)

trust me, 40mm (still called 1 1/2" by the old guys, I am mid 50's and too young to do that!) is different

push fit is 40.8mm od, solvent weld 43mm od. Doesn't sound a lot, but they are not interchangeable. (that's where waste compression fittings come in handy)

[Colin Lindsay]

That is quite a bit when talking about a push fit; if I'm right 1.5 inches is 3.8 cm so 38mm. Happily I'd be looking at the t-piece being bigger than the tubing... wonder if it stretches at all?

[PeteH]

Standard (common) sizes are 21.5mm, overflow. 32mm, sink and basins. 40mm, Sinks and Baths. And then there are the differing types of fittings. Push,solvent welded, and Compression. Having done I full self build, I full Refurb; and other stuff for various family members I guess I am familiar with them all, and have a variety stuffed under the bench somewhere!. Some 150mm sewer pipe lurking outside along with odd fittings too.

Reading that, I realise just how sad I have become!.

Pete

[Clive]

7 hours ago, Colin Lindsay said:

That is quite a bit when talking about a push fit; if I'm right 1.5 inches is 3.8 cm so 38mm. Happily I'd be looking at the t-piece being bigger than the tubing... wonder if it stretches at all?

measure the tubing, but it may be  a reasonable fit, and a bead or LMN silicone or PU adhesive (or whatever) would fill any gaps. 

[Peter Truman]

On the Vitesse and presumably Herald to shorten the radii of the windscreen vent piping I used 32mm ID PVC Pressure Elbows, which has a pipe PD of 38mm and a socket OD of 41mm. The steel Internal Heater Distributor end of the PVC socket had to be internally opened out (now female end) to 38mm by using a Dremel drum sanding disc, whilst the flexible piping end had to be trimmed down to 38mm (now male end) for the piping to fit over, see photo of elbow below. Second photo is the elbows fitted to the standard Heater Distributor box, with neat piping connected. The flexible plastic piping I used was from a Jag and was a single long run where the heater outlet warmed the rear passengers, it is a sort of corrugated pipe with no wire coil making it easier to manoeuvre around obstacles.

The third photo is the original Mk2 Vitesse internal cab heater deflector attached I believe to the drivers side to stop the hot air flow from the std heater distributor cooking the left foot instead it deflects the air flow over the footwell. The fitting is screwed onto the top RH bolt of the gearbox cover. 

[Colin Lindsay]

8 hours ago, Peter Truman said:

The third photo is the original Mk2 Vitesse internal cab heater deflector attached I believe to the drivers side to stop the hot air flow from the std heater distributor cooking the left foot instead it deflects the air flow over the footwell. The fitting is screwed onto the top RH bolt of the gearbox cover.

Used in the Herald Estate too; but only ever on the drivers' side. The poor passenger didn't count!