Lotus Elan

It's getting hot in here...

PostPost by: Robbie693 » Mon Jun 12, 2006 2:10 pm

Why can't I get cold air through the heater? (If that's not a contradiction in terms)

I've adjusted the cables and they move the acctuators on the heater unit. Sealed up the hoses, although offside demister hose wasn't long enough to reach the heater outlet whilst attached to the dash top, so I taped it up. I know the fan works because I get fresh air from the side vents (blessed relief!)

But still I get hot air all the time, very little output (apart from the side vents) and it seems to come out of the demister and knee warmer at the same time.

Confused and sweating

Any ideas?
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PostPost by: marcfuller » Mon Jun 12, 2006 3:16 pm

+2 are always running coolant through the heater core/matrix. They do not have a valve as the Elans do. You need to add a valve and close it or otherwise stop the flow of coolant through the core.
-Marc '66 Elan DHC (36/6025)
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PostPost by: john.p.clegg » Mon Jun 12, 2006 3:36 pm

Robbie
The problem I had with mine was the seals on the flaps in the heater,they were nearly 40 years old and as perished as a perished thing.
Hot air was getting everywhere all the time through the gaps.The cure was to strip the heater out and make-up new flap seals out of some rubber strip and replace the perished ones- it's not an easy job and helps if you have a spare heater box to refurbish then swap-but now it works like it was intended all those years ago

John :wink:
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PostPost by: niallf » Mon Jun 12, 2006 3:59 pm

John's right, it's all down to flap sealage!

In the section on dash build here...
http://community.webshots.com/user/niallf18

...there's a few cut away heater box shots.

I've modded mine to allow fitting of a modern depth (DIN) radio, but this prevents full flap movement and has messed up my car's demisting capabilities. OK in the summer, pain in the winter.

Allows you a glimpse inside without the mamoth dismantling job, though.

Good Luck,

Niall
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PostPost by: Robbie693 » Mon Jun 12, 2006 4:50 pm

Ugh! I was hoping that wasn't the case...

I assume you can't get at the flaps without removing the unit (ie disconnecting the heater matrix)?

Is it possible to get at the hose connections in the engine bay? The only time I have disconnected those was when I had the cylinder head off, can you reach them without?

Also, is the heater held together with screws or pop-rivets?
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PostPost by: M100 » Mon Jun 12, 2006 6:11 pm

Relying on flaps to cut off airflow through the matrix is always going to be a cheap and nasty bodge and surely getting the heater out has to involve removing the dash (cue electrical problems as wires fall off)

Despite the Chapman simpilcate and add lightness methodology my advice would be to fit a shutoff valve, either the one fitted on the 2 seaters that screws into the head, a manual one based on a gas shutoff cock, or a vacuum operated one as used on 80's/90's Jags fitted inline with the heater pipe.

The 2 seater valve can be latched closed as installed and to open it fully for winter just needs a cable tie.
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PostPost by: Robbie693 » Tue Jun 13, 2006 9:11 am

That's a thought, would it be possible to attach the hot/cold control cable to the valve instead of the flap?
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PostPost by: M100 » Tue Jun 13, 2006 1:50 pm

Possibly but you'd loose the air blending (I assume?) the 2 heater has. i.e. hot air to footwells cooler air to the dash vents although if you could take another cable from the lever on the heater to the valve under the bonnet and arranged it so each operated at the correct rate (by adjusting the lever arm length) you could get the best of both worlds, an air blending heater and a proper cold shutoff.

Maybe fit the valve first, see if you can manage with the manual underbonnet operation method and then fix the heater at your leisure maybe over the winter months or just leave the valve on standby for those really hot days when you know you won't need the heater and wish you had aircon. :D
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PostPost by: niallf » Tue Jun 13, 2006 1:54 pm

Robbie693 wrote:Also, is the heater held together with screws or pop-rivets?


Mine was riveted at one end and screwed at the other.

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PostPost by: Robbie693 » Wed Jun 14, 2006 9:10 am

Right, that gives me a few options. Thanks guys.

Niall - very usefull pics by the way, cheers :D
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